Draba
Draba incrassata
Draba, whitlow-grass, whitlow-wort
Sweetwater Draba, Sweetwater Mountains Draba
usually erect to ascending, sometimes decumbent or prostrate, unbranched or branched (usually distally).
unbranched, 0.2–0.8 dm, glabrous throughout.
usually basal and cauline, sometimes cauline absent;
petiolate or sessile;
basal usually rosulate, usually petiolate, rarely sessile, blade margins usually entire or toothed, rarely pinnately lobed;
cauline (when present), petiolate or sessile, blade (base cuneate [auriculate]), margins entire or dentate.
rosulate;
subsessile;
petiole ciliate;
blade (thick and somewhat fleshy), obovate to spatulate or oblanceolate, 0.3–1 cm × 1.5–4.5 mm, margins entire, (sometimes sparsely ciliate), surfaces glabrous or pubescent proximal to apex, with simple and fewer, short-stalked, 2-rayed trichomes, 0.2–0.7 mm.
0.
(often corymbose, sometimes bracteate), elongated or not in fruit.
8–22-flowered, ebracteate, elongated in fruit;
rachis not flexuous, glabrous.
sepals (rarely persistent), erect, ascending, or, rarely, spreading, ovate or oblong [elliptic], lateral pair not saccate or subsaccate basally;
petals (erect or ascending to patent), yellow, white, pink, purple, or orange [red], obovate, spatulate, oblanceolate, or linear [orbicular, oblong], (longer than or, rarely, shorter than sepals), claw obscurely to well-differentiated from blade, (apex obtuse, rounded, notched, or, rarely, deeply 2-lobed);
stamens slightly to strongly tetradynamous;
filaments dilated or not basally, (glabrous);
anthers ovate or oblong, (not apiculate);
nectar glands (1, 2, or 4), distinct or confluent, subtending bases of stamens, median glands present or absent.
sepals oblong, 1.7–3 mm, glabrous or pubescent, (trichomes subapical, simple or 2-rayed);
petals bright yellow, oblanceolate to spatulate, 3–5 × 1.7–2.5 mm;
anthers oblong, 0.4–0.6 mm.
(proximalmost) erect or ascending to divaricate, slender.
horizontal to divaricate-ascending (distinctly decurrent basally), curved upward, 3–7(–10) mm, glabrous.
silicles or siliques, sessile, ovate, lanceolate, elliptic, oblong, linear, suborbicular, ovoid, or subglobose, plane or spirally twisted, smooth, (not keeled, unappendaged), usually latiseptate, rarely terete;
valves (papery), each with distinct or obscure midvein and lateral veins, glabrous or pubescent;
replum rounded;
septum complete;
ovules 4–70(–88) per ovary;
style obsolete or distinct;
stigma capitate.
ovate to ovate-lanceolate or narrowly elliptic-lanceolate, plane, flattened, 3–7(–10) × 2.2–4.5 mm;
valves usually glabrous, rarely sparsely puberulent, trichomes simple, 0.03–0.1 mm;
ovules 8–12 per ovary;
style 0.2–0.8 mm.
biseriate, oblong, ovate, or orbicular, usually flattened (slightly flattened in D. aleutica, D. verna), usually not winged (winged in D. asterophora, D. brachycarpa, D. carnosula, D. pterosperma);
seed coat (minutely reticulate), not mucilaginous when wetted;
cotyledons accumbent.
oblong, 1.5–1.8 × 0.8–1.1 mm.
= 6–12.
= 24.
Draba
Draba incrassata
North America; Mexico; South America (Andes, Colombia to Patagonia); Europe; Asia; nw Africa; alpine and boreal; rarely in temperate and low-elevation areas of North America and Eurasia
CA
Species ca. 380 (121 in the flora).
Draba, the largest genus in Brassicaceae, is a well-defined, monophyletic, and complex group represented by native species on all continents except Australia and Antarctica. It is poorly developed in Africa. The four centers of highest diversity include western North America, subarctic regions, Himalaya, and high Andes.
The infrageneric classification of Draba is problematic, and preliminary molecular studies (M. Koch and I. A. Al-Shehbaz 2002) do not support the circumscriptions of most of the 17 sections recognized by O. E. Schulz (1927, 1936). A. I. Tolmatchew (1939, 1975) recognized representatives of 29 series occurring within the former Soviet Union, and his classification is far more practical that Schulz’s, though it covers only a small portion of the genus. An overall comprehensive infrageneric taxonomy of Draba is needed.
Much of the complexity within Draba is attributed to hybridization, disploidy, polyploidy, and apomixis; the interested reader should consult E. Ekman (1932b), T. W. Böcher (1966), C. Brochmann (1992, 1992b, 1993), Brochmann and R. Elven (1992), Brochmann et al. (1992, 1992b, 1992c, 1992d, 1993), G. A. Mulligan (1970, 1971, 1971b, 1972, 1974, 1975, 1976), Mulligan and J. N. Findlay (1970), and M. D. Windham (2000, 2004). Except for the results of some studies (e.g., Mulligan and Findlay; Brochmann et al. 1992d; Brochmann 1993; H. H. Grundt et al. 2005), little is known about the reproductive biology of Draba species. The polyphyletic origins of some species (e.g., D. cacuminum, D. corymbosa, D. lactea) have been well-documented (Brochmann et al. 1992b, 1992c; Grundt et al. 2004).
Knowledge of chromosome numbers, combined with a critical study of morphology, is essential in the delimitation of Draba species and in understanding their origin. In addition to the works by T. W. Böcher, C. Brochmann, H. H. Grundt, G. A. Mulligan, and M. D. Windham cited above, those by O. Heilborn (1927) and G. Knaben (1966) also are pertinent. Although the base chromosome number in the genus ranges from six to twelve, the majority of the species (ca. 67%) are based on eight, as compiled from S. I. Warwick and I. A. Al-Shehbaz (2006). The highest chromosome number in the genus, 2n = 144 (18-ploid), was reported by Mulligan (1974b) for D. corymbosa, and a complex, intraspecific disploid series (see below) was documented in D. verna (Ø. Winge 1940).
Although Erophila is recognized in recent floras as distinct from Draba, the sole characteristic on which it is based (petal apex deeply 2-fid versus emarginate to entire in Draba) is unreliable, and it is well-nested within the larger and highly diversified Draba (M. Koch and I. A. Al-Shehbaz 2002).
Because some superficially similar species of Draba grow sympatrically, extra care must be taken in recording flower color and in collecting voucher material for cytological or molecular studies. Cases in point are Thompson & Thompson 578a (DAO), a collection that consists of four species (see 2. D. albertina), and Bruggeman 41 (DAO), one that includes D. fladnizensis, D. lactea, and D. nivalis.
The number of ovules per ovary is taxonomically important in Draba, but this is rather difficult to determine in the ovary. Counting total number of aborted ovules plus mature seeds per fruit should determine the overall ovule number. The use of seed number per fruit often is unreliable because tremendous variation can be found on the same plant as a result of the failure of some ovules to develop into mature seeds. The number of flowers is counted from the main raceme of a plant with branched stems, the length of style is measured from mature fruits, and the size of basal leaves is taken from the largest leaves of the rosette. In order to accurately determine a given collection to species, complete specimens with flowers and mature fruits are needed. Finally, although most authors of this account prefer to use the subspecific rather the varietal rank, no attempt was made here to enforce the choice of either; no new combinations have been made.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Although originally treated as a variety of Draba lemmonii, D. incrassata is quite distinct both morphologically (R. A. Price and R. C. Rollins 1991) and chromosomally (M. D. Windham, unpubl.). The species is known from the Sweetwater Mountains in Mono County.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key to Species Groups of Draba
1. Annuals or biennials, without caudex or stolons, not pulvinate, not cespitose | Group 1 |
1. Perennials, with caudex or, rarely, stolons, sometimes pulvinate or cespitose | → 2 |
2. Cauline leaves of flowering stems 1+ | → 3 |
2. Cauline leaves of flowering stems 0 | → 6 |
3. Abaxial surface of leaf blades glabrous or with simple trichomes | Group 2 |
3. Abaxial surface of leaf blades with only branched trichomes | → 4 |
4. Fruit valves glabrous | Group 3 |
4. Fruit valves pubescent or puberulent (at least on margin) | → 5 |
5. Abaxial surface of leaf blades with at least some 7-15-rayed trichomes | Group 4 |
5. Abaxial surface of leaf blades with 2-4(-6)-rayed trichomes | Group 5 |
6. Rachises glabrous | → 7 |
6. Rachises sparsely to densely pubescent | → 8 |
7. Abaxial surface of leaf blades glabrous (sometimes trichomes only on margins and apices) | Group 6 |
7. Abaxial surface of leaf blades pubescent | Group 7 |
8. Leaf blade margins not ciliate | Group 8 |
8. Leaf blade margins ciliate | → 9 |
9. Abaxial surface of leaf blades usually with simple or simple and branched trichomes, rarely glabrous | Group 9 |
9. Abaxial surface of leaf blades with branched trichomes | Group 10 |
Group 1
1. Cauline leaves 0 | → 2 |
1. Cauline leaves 1-54(-76) | → 7 |
2. Petals deeply 2-fid; rachises of fruiting racemes flexuous. | D. verna |
2. Petals usually obtuse, rarely emarginate; rachises of fruiting racemes usually straight, if flexuous then petals yellow | → 3 |
3. Petals white; late-season flowers apetalous; fruit valves usually with antrorse, simple trichomes, rarely glabrous | → 4 |
3. Petals yellow; late-season flowers with petals; fruit valves usually glabrous, rarely puberulent | → 5 |
4. Racemes 10-50(-70)-flowered, elongated in fruit, rachises densely pubescent; fruiting pedicels densely pubescent. | D. cuneifolia |
4. Racemes (3-)5-12(-16)-flowered, subumbellate in fruit, rachises usually glabrous, rarely sparsely pubescent; fruiting pedicels glabrous or sparsely pubescent. | D. reptans |
5. Abaxial surface of leaf blades glabrous or sparsely pubescent, trichomes simple and 2-rayed; stems usually glabrous, rarely pubescent proximally, trichomes simple. | D. crassifolia |
5. Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; stems pubescent, trichomes 2-4-rayed (sometimes simple) | → 6 |
6. Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12(-15) mm. | D. albertina |
6. Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-)10-17(-20) mm. | D. stenoloba |
7. Styles (0.8-)1-3.5 mm | → 8 |
7. Styles 0.01-0.6 (-0.8) mm | → 12 |
8. Adaxial surface of basal leaf blade pubescent with simple, subsetiform trichomes, rarely mixed with 2-rayed ones; fruit valves sparsely puberulent, trichomes simple. | D. bifurcata |
8. Adaxial surface of basal leaf blade pubescent with at least some 2-4-rayed trichomes; fruit valves usually pubescent, rarely glabrous, trichomes 2-4-rayed | → 9 |
9. Petals linear, 0.2-0.5 mm wide; s California. | D. corrugata |
9. Petals oblanceolate to spatulate, 1-3.5 mm wide; se Arizona, Colorado, New Mexico, Utah | → 10 |
10. Fruits plane, valves pubescent, trichomes 2-4-rayed; petals 3-5 × 1-1.5 mm, often fading whitish; Utah. | D. santaquinensis |
10. Fruits slightly to strongly twisted, valves glabrous, pubescent, or puberulent, trichomes simple and 2(-4)-rayed; petals 5-8.5 × 1.5-3.5 mm, not fading whitish; Arizona, Colorado, New Mexico | → 11 |
11. Cauline leaves (8-)12-31(-43); rachises pubescent; fruiting pedicels 4-10(-13) mm. | D. helleriana |
11. Cauline leaves 1-3; rachises often glabrous or, rarely, sparsely pubescent; fruiting pedicels (6-)9-18(-22) mm. | D. mogollonica |
12. Racemes bracteate basally; fruiting pedicels erect to ascending (subappressed to rachises); cauline leaves (15-)22-54(-76), densely overlapping proximally. | D. incana |
12. Racemes ebracteate; fruiting pedicels horizontal to divaricate-ascending (not appressed to rachises); cauline leaves 1-15(-25), seldom overlapping | → 13 |
13. Rachises glabrous | → 14 |
13. Rachises pubescent | → 18 |
14. Petals white or, rarely, absent; basal leaves not rosulate; racemes subumbellate in fruit. | D. reptans |
14. Petals yellow; basal leaves rosulate; racemes elongated in fruit | → 15 |
15. Cauline leaves 4-12(-15); fruiting pedicels 7-28(-35) mm, (1.5-)2-7 times longer than fruit. | D. nemorosa |
15. Cauline leaves 1-3(-5); fruiting pedicels (1-)3-14(-19) mm, subequaling or shorter than fruit | → 16 |
16. Abaxial surface of leaf blades glabrous or sparsely pubescent, trichomes simple and 2-rayed; stems usually glabrous, or, rarely, sparsely pubescent proximally, trichomes simple. | D. crassifolia |
16. Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; stems pubescent basally, trichomes 2-4-rayed (sometimes simple) | → 17 |
17. Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12(-15) mm. | D. albertina |
17. Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-)10-17(-20) mm. | D. stenoloba |
18. Leaf blade surfaces with cruciform trichomes | → 19 |
18. Leaf blade surfaces with simple and 2-7-rayed trichomes | → 20 |
19. Fruit valves pubescent; ovules 4-6(-8) per ovary. | D. aprica |
19. Fruit valves glabrous; ovules 8-16(-20) per ovary. | D. brachycarpa |
20. Fruits obovate to obovate-oblong. | D. platycarpa |
20. Fruits elliptic, oblong, linear, lanceolate, or, rarely, ovate | → 21 |
21. Late-season flowers apetalous; basal leaves not rosulate | → 22 |
21. Late-season flowers with petals; basal leaves rosulate | → 23 |
22. Racemes 10-50(-70)-flowered, elongated in fruit, rachises denselypubescent; fruiting pedicels densely pubescent. | D. cuneifolia |
22. Racemes (3-)5-12(-16)-flowered, subumbellate in fruit, rachises glabrous or, rarely, sparsely pubescent; fruiting pedicels glabrous or sparsely pubescent. | D. reptans |
23. Abaxial surface of leaf blades pubescent, trichomes 3-6-rayed; petals white. | D. praealta |
23. Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; petals yellow (sometimes fading white) | → 24 |
24. Styles 0.2-0.6(-0.8) mm; fruits 2-3.5 mm wide, valves pubescent, trichomes simple and 2-rayed. | D. brachystylis |
24. Styles 0.01-0.15 mm; fruits 1.3-2.3 mm wide, valves glabrous or pubescent, trichomes simple | → 25 |
25. Cauline leaves 3-10(-17); racemes (15-)20-51(-62)-flowered; fruits lanceolate, 6-9(-11) mm; Arizona, Colorado, New Mexico, Utah. | D. rectifructa |
25. Cauline leaves 1 or 2(-4); racemes (2-)4-10(-15)-flowered; fruits usually linear, rarely linear-elliptic, (8-)10-17(-20) mm; Alaska, Alberta, British Columbia, Washington, Yukon. | D. stenoloba |
Group 2
1. Plants stoloniferous; basal leaves not rosulate (subopposite). | D. ogilviensis |
1. Plants not stoloniferous (usually cespitose); basal leaves rosulate | → 2 |
2. Abaxial surface of leaf blades glabrous | → 3 |
2. Abaxial surface of leaf blades pubescent | → 9 |
3. Fruit valves pubescent, trichomes simple and 2-4-rayed; styles (0.7-)1.6-3 mm; petals 5.5-8 mm; n California and s Oregon. | D. howellii |
3. Fruit valves glabrous or puberulent, trichomes simple; styles 0.02-1.2(-1.8) mm; petals 1.5-5(-6) mm; not California nor Oregon | → 4 |
4. Racemes bracteate; basal leaf blades linear to linear-oblanceolate. | D. graminea |
4. Racemes ebracteate; basal leaf blades usually obovate to oblanceolate, rarely linear-lanceolate | → 5 |
5. Cauline leaves 1; fruits plane; styles 0.02-0.4(-0.6) mm | → 6 |
5. Cauline leaves (1 or) 2-8; fruits slightly twisted or plane; styles (0.4-) 0.7-1.2(-1.8) mm | → 7 |
6. Petals yellow (often fading white), oblanceolate, 1.5-2.5(-3) × 0.5-1 mm; stems glabrous or with simple trichomes; styles 0.02-0.1 mm. | D. crassifolia |
6. Petals white, obovate, 3-5 × 1.8-3 mm; stems glabrous or with 2-8-rayed trichomes; styles 0.1-0.4(-0.6) mm. | D. lactea |
7. Basal leaves undifferentiated into blade and petiole, 0.5-0.8 cm, persisting as a whole, imbricate, blade margins with setiform trichomes. | D. heilii |
7. Basal leaves differentiated into blade and petiole, 1.2-8.5 cm, petiole persisting, not imbricate, blade margins without setiform trichomes | → 8 |
8. Fruits lanceolate to ovate-lanceolate, (7-)8-14 × 3-5 mm; rachises pubescent (trichomes crisped); Colorado, Montana, Utah Wyoming. | D. crassa |
8. Fruits linear-elliptic to elliptic, 5-10(-13) × 1.5-2.5 mm; rachises usually glabrous, rarely pubescent (trichomes non-crisped); se Arizona, s New Mexico, w Texas. | D. standleyi |
9. Fruit valves pubescent, trichomes 2-12-rayed | → 10 |
9. Fruit valves glabrous, pubescent, or puberulent, trichomes simple | → 13 |
10. Styles 1.4-3.4 mm; cauline leaves (4-)6-10(-13); racemes (10-)18-55(-67)- flowered; petals yellow, linear. | D. corrugata |
10. Styles 0.1-0.8 mm; cauline leaves 1-3; racemes 2-20-flowered; petals white, spatulate to obovate | → 11 |
11. Fruits 2-5 × 1.5-2 mm; ovules 36-52 per ovary; petals 1.5-2 × 0.7-0.8 mm. | D. yukonensis |
11. Fruits 4-9.5 × 2-4 mm; ovules 20-36 per ovary; petals 3-5 × 1.5-2.5 mm | → 12 |
12. Fruits with 2-4-rayed and, sometimes, fewer, simple trichomes; petals 3-4 mm; stems proximally with branched trichomes 2-6-rayed. | D. arctogena |
12. Fruits with (2-)5-12-rayed trichomes; petals 3.5-5 mm; stems proximally with branched trichomes 4-10-rayed. | D. oblongata |
13. Styles (0.7-)1-3 mm; fruits usually twisted, rarely plane; petals (4-)4.5-7.5 mm | → 14 |
13. Styles 0.01-1(-1.2) mm; fruits not or, rarely, slightly twisted; petals 1.5-4(-4.5) mm | → 17 |
14. Cauline leaf blade margins dentate; fruiting pedicels horizontal to divaricate; se Arizona. | D. bifurcata |
14. Cauline leaf blade margins entire; fruiting pedicels usually ascending, rarely divaricate-ascending; Arizona, Colorado, New Mexico, Texas, Wyoming | → 15 |
15. Fruits usually twisted (to 3 turns), rarely plane; stems proximally with trichomes 0.4-2.2 mm; ovules 20-34 per ovary; c Colorado, n New Mexico, se Wyoming. | D. streptocarpa |
15. Fruits usually twisted (to 1 turn), rarely plane; stems proximally with trichomes 0.1-0.7 mm; ovules 12-24 per ovary; se Arizona, s New Mexico, w Texas | → 16 |
16. Basal leaves undifferentiated into blade and petiole, 0.5-0.8 cm, persisting as a whole, imbricate, blade margins with setiform trichomes. | D. heilii |
16. Basal leaves differentiated into blade and petiole, 1.2-8.5 cm, petiole persisting, not imbricate, blade margins without setiform trichomes. | D. standleyi |
17. Annuals, biennials, or perennials (not cespitose); fruiting pedicels (3-)5-14 (-16) mm | → 18 |
17. Perennials (cespitose); fruiting pedicels 1-6 mm | → 19 |
18. Abaxial surface of leaf blades pubescent with 2-4-rayed trichomes; stems pubescent, trichomes simple and 2-rayed. | D. albertina |
18. Abaxial surface of leaf blades glabrous or with some simple and 2-rayed trichomes; stems usually glabrous, rarely pubescent basally, trichomes simple. | D. crassifolia |
19. Petals yellow, 1-2 mm wide; styles (0.2-)0.3-1.2 mm | → 20 |
19. Petals white, 0.4-1(-1.5) mm wide; styles 0.05-0.2(-0.3) mm | → 22 |
20. Abaxial surface of leaf blades with sessile or subsessile, appressed, 2-4-rayed trichomes; fruits ovate, 4-8 mm; styles 0.2-0.3 mm. | D. weberi |
20. Abaxial surface of leaf blades with stalked 2- or 3-rayed trichomes; fruits lanceolate to oblong-lanceolate, 4-13 mm; styles 0.3-1.2 mm | → 21 |
21. Petals 2-2.5(-3) mm, erect, not clawed; anthers oblong, 0.6-0.9 mm; fruits plane; rachises usually glabrous, rarely sparsely pubescent. | D. exunguiculata |
21. Petals 3-4.5 mm, not erect (flared, clawed); anthers ovate, 0.3-0.5 mm; fruits twisted or plane; rachises pubescent. | D. grayana |
22. Fruit valves glabrous; stems glabrous or, rarely, sparsely pubescent (trichomes straight); petals 2-3.5 × 0.8-1.5 mm. | D. fladnizensis |
22. Fruit valves usually pubescent, rarely glabrous; stems pubescent (trichomes crisped); petals 1.5-2 × 0.4-0.8 mm | → 23 |
23. Racemes 2-7-flowered, rachises glabrous; sepals caducous; fruits lanceolate, flattened; Yukon. | D. kluanei |
23. Racemes (3-)6-13(-17)-flowered, rachises pubescent or, rarely, glabrous; sepals persistent; fruits ovoid to subellipsoid, slightly inflated basally; e California. | D. monoensis |
Group 3
1. Basal leaf blade surfaces with malpighiaceous trichomes. | D. malpighiacea |
1. Basal leaf blade surfaces with simple, 2-rayed, forked, stellate, or dendritic trichomes | → 2 |
2. Abaxial surface of leaf blades with some 7-15-rayed trichomes | → 3 |
2. Abaxial surface of leaf blades with 2-5 (or 6)-rayed trichomes | → 11 |
3. Petals yellow; stem and basal leaf trichomes crisped. | D. streptobrachia |
3. Petals white or creamy white; stem and basal leaf trichomes usually non-crisped | → 4 |
4. Margins of basal and cauline leaf blades entire | → 5 |
4. Margins of basal and, sometimes, cauline leaf blades usually dentate or denticulate, if entire, racemes not flexuous in fruit | → 8 |
5. Plants usually forming mats; rachises slightly flexuous | → 6 |
5. Plants not forming mats; rachises not flexuous | → 7 |
6. Fruits 6-15(-18) mm; adaxial surface of leaf blades with simple and long-stalked, 2-rayed trichomes. | D. lonchocarpa |
6. Fruits 3.5-9 mm; adaxial surface of leaf blades with short-stalked, 8-15-rayed trichomes. | D. nivalis |
7. Rachises pubescent; ovules 22-32 per ovary; sepals persistent (until fruiting); e California, w Nevada. | D. californica |
7. Rachises glabrous; ovules 12-16 per ovary; sepals caducous; Alaska, Alberta, w Montana, nw Wyoming. | D. porsildii |
8. Cauline leaves usually 0, rarely 1 (as a bract); basal leaf blades each with prominent midvein; sepals glabrous or, rarely, with simple trichomes subapically. | D. lactea |
8. Cauline leaves usually 2-25, rarely 1 (D. chamissonis); basal leaf blades each with obscure midvein; sepals with 2-5-rayed trichomes | → 9 |
9. Fruits 1.1-1.6(-2) mm wide; petals 2-3.5 mm; petiole margins not ciliate; proximalmost flowers bracteate. | D. chamissonis |
9. Fruits 2-3.5 mm wide; petals 3.5-5.5 mm; petiole margins ciliate; proximalmost flowers usually ebracteate (sometimes bracteate in D. glabella) | → 10 |
10. Abaxial surface of leaf blades with sessile, stellate trichomes; styles (0.2-)0.4-1 mm; stems proximally with 8-12-rayed trichomes. | D. arabisans |
10. Abaxial surface of leaf blades with short-stalked, stellate trichomes; styles 0.05-0.2(-0.5) mm; stems proximally with some simple trichomes. | D. glabella |
11. Stem and leaf trichomes sessile, 2 rays parallel to long axis of stem or midvein, some malpighiaceous. | D. spectabilis |
11. Stem and leaf trichomes stalked, rays not parallel to long axis of stem or midvein, not malpighiaceous | → 12 |
12. Caudex fleshy, simple; petiole of basal leaves (1-)4-15 cm; fruits 4-7(-9) mm wide. | D. grandis |
12. Caudex not fleshy, usually branched, rarely simple; petiole of basal leaves obsolete or 1-2 cm; fruits 1-4(-6) mm wide | → 13 |
13. Abaxial surface of leaf blades with either cruciform or pectinate trichomes | → 14 |
13. Abaxial surface of leaf blades with cruciform and 2-6-rayed trichomes | → 15 |
14. Plants pulvinate, caudex densely branched; abaxial surface of leaf blades with pectinate trichomes; ovules 8-16(-20) per ovary. | D. incerta |
14. Plants not pulvinate, caudex loosely branched; abaxial surface of leaf blades with cruciform trichomes; ovules 16-30 per ovary. | D. juvenilis |
15. Seeds 1.8-2.8 × 1.2-2 mm, wing 0.5-1 mm wide; fruits (3.5-)4-6 mm wide. | D. asterophora |
15. Seeds 0.7-1.4(-1.6) × 0.4-0.8(-1) mm, not winged; fruits 1-4(-5) mm wide | → 16 |
16. Styles (0.6-)0.8-3.6 mm; petals 4-8.5 mm; anthers usually oblong (ovate in D. murrayi) | → 17 |
16. Styles 0.01-0.6 mm; petals 1.8-4 mm; anthers ovate | → 19 |
17. Petals white; anthers ovate, 0.4-0.5 mm; fruits 1.5-2 mm wide; styles 0.6-1.5 mm. | D. murrayi |
17. Petals yellow; anthers oblong, 0.6-1 mm; fruits 2-5 mm wide; styles (0.8-)1-3.6 mm | → 18 |
18. Fruits plane; ovules 10-18 per ovary; basal leaf blades (2-) 4-10(-14) mm wide; cauline leaves (3-)5-9(-11); petals 4-6 mm. | D. abajoensis |
18. Fruits slightly twisted; ovules 24-36 per ovary; basal leaf blades 7-25(-33) mm wide; cauline leaves 1-3; petals (5-) 6-8.5 mm. | D. mogollonica |
19. Rachises usually glabrous, (rarely sparsely pubescent in D. stenoloba); fruits usually linear, elliptic, or linear-lanceolate, rarely lanceolate, 1-2(-2.5) mm wide; styles 0.01-0.15(-0.2) mm | → 20 |
19. Rachises pubescent; fruits lanceolate to oblong or ovoid, (1.8-) 2-4 mm wide; styles 0.1-0.6 mm | → 22 |
20. Sepals pubescent, trichomes simple and 2- or 3-rayed; abaxial surface of leaf blades with trichomes (2-)4(-6)-rayed. | D. paucifructa |
20. Sepals glabrous or sparsely pubescent, trichomes simple; abaxial surface of leaf blades with trichomes 2-4-rayed | → 21 |
21. Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12 (-15) mm. | D. albertina |
21. Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-)10-17(-20) mm. | D. stenoloba |
22. Petals yellow; fruits ovoid to ovoid-lanceolate, inflated (at least basally); ovules (4-)8-12 per ovary. | D. sobolifera |
22. Petals white or creamy white; fruits oblong, lanceolate, or lanceolate-elliptic, flattened; ovules 18-32 per ovary | → 23 |
23. Fruiting pedicels pubescent, trichomes 4-8-rayed; sepals persistent; petals 0.8-1 mm wide; e California, w Nevada. | D. californica |
23. Fruiting pedicels pubescent, trichomes simple and 2-4-rayed; sepals caducous; petals 1.7-2.5 mm wide; Canada, Greenland. | D. norvegica |
Group 4
1. Fruit trichomes 2-7-rayed (at least on replum); petals white | → 2 |
1. Fruit trichomes simple and 2-5-rayed; petals white or yellow | → 8 |
2. Racemes bracteate (at least basally) | → 3 |
2. Racemes ebracteate | → 4 |
3. Racemes (10-)15-47(-63)-flowered, often considerably elongated in fruit; ovules 28-48 per ovary. | D. cana |
3. Racemes 2-5(-8)-flowered, slightly elongated in fruit; ovules 16-24 per ovary. | D. inexpectata |
4. Petals 2-3.5 × 0.7-1.4 mm; fruits 1.5-2.5 mm wide | → 5 |
4. Petals 3.5-6 × 1.5-2.5 mm; fruits 2-3.5 mm wide | → 6 |
5. Cauline leaves 1-3(-6); fruits usually twisted, rarely plane; rachises not flexuous in fruit; ovules 28-40 per ovary; California. | D. breweri |
5. Cauline leaf 1; fruits plane; rachises often slightly flexuous in fruit; ovules 12-24(-28) per ovary; Alaska, Canada, Greenland. | D. nivalis |
6. Basal leaf blade margins dentate or denticulate; fruits usually slightly twisted, rarely plane; styles (0.2-)0.4-1 mm. | D. arabisans |
6. Basal leaf blade margins usually entire, rarely 1-toothed on each side; fruits plane; styles 0.1-0.6 mm | → 7 |
7. Basal leaf blades with simple trichomes apically, abaxial surfaces with distinct midveins; seeds 0.8-1.1 × (0.6-)0.7-0.8 mm. | D. arctica |
7. Basal leaf blades without simple trichomes apically, abaxial surfaces with obscure midveins; seeds 0.6-0.8 × 0.4-0.6 mm. | D. cinerea |
8. Petals yellow | → 9 |
8. Petals white | → 11 |
9. Ovules 28-38(-44) per ovary; racemes basally bracteate, (10-)18-52(-72)-flowered; cauline leaves 5-20(-26); fruits (6-)9-14(-17) mm, often subappressed to rachis; stem trichomes non-crisped. | D. aurea |
9. Ovules 6-16(-18) per ovary; racemes ebracteate, 3-15(-18)-flowered; cauline leaves 1-4 (or 5); fruits 3-10 mm, not appressed to rachis; stem trichomes often crisped | → 10 |
10. Plants matted, caudex branches creeping; stem trichomes dendritic; ovules 6-12 per ovary; se Utah. | D. ramulosa |
10. Plants not matted, caudex branches not creeping; stem trichomes stellate; ovules 10-16(-18) per ovary; Colorado. | D. streptobrachia |
11. Styles (0.7-)1-2(-2.3) mm; fruits twisted; sw Colorado. | D. smithii |
11. Styles 0.05-0.6(-0.8) mm; fruits plane or slightly twisted; not sw Colorado | → 12 |
12. Leaf blade margins dentate or denticulate; cauline leaves 2-25 | → 13 |
12. Leaf blade margins entire; cauline leaves 1(-4) | → 14 |
13. Leaf blade surfaces pubescent, trichomes cruciform or (2-)4-6-rayed (rays usually simple, rarely branched); plants with rhizomatous caudex. | D. borealis |
13. Leaf blade surfaces pubescent, trichomes stellate-pectinate, 4-8(-12)- rayed; plants without rhizomatous caudex (sometimes cespitose). | D. glabella |
14. Rachises not flexuous; sepals persistent; fruits plane. | D. californica |
14. Rachises often slightly flexuous; sepals caducous; fruits slightly twisted or plane. | D. lonchocarpa |
Group 5
1. Fruit trichomes 2-rayed and/or simple | → 2 |
1. Fruit trichomes 4-rayed (some) (except D. saxosa 2- or 3-rayed) | → 12 |
2. Stem and leaf trichomes sessile, 2 rays parallel to long axis of stem or midvein, some trichomes malpighiaceous. | D. spectabilis |
2. Stem and leaf trichomes stalked, rays not parallel to long axis of stem or midvein, not malpighiaceous | → 3 |
3. Abaxial surface of basal leaf blades with cruciform trichomes | → 4 |
3. Abaxial surface of basal leaf blades with 2-6-rayed trichomes | → 5 |
4. Fruits plane; styles 0.2-0.7 mm; Alaska, Canada. | D. juvenilis |
4. Fruits often strongly twisted; styles 0.8-1.8(-2.5) mm; Arizona. | D. petrophila |
5. Fruits appressed or subappressed to rachises; proximalmost flowers bracteate. | D. aurea |
5. Fruits not appressed to rachises; proximalmost flowers ebracteate | → 6 |
6. Styles (1-)1.5-3.5 mm. | D. helleriana |
6. Styles usually 0.01-0.9 mm, if longer (D. pennellii), plants pulvinate or petals white | → 7 |
7. Plants not cespitose or pulvinate, caudex simple or poorly developed; fruits (7-)10-17(-20) mm; ovules 20-36(-42) per ovary | → 8 |
7. Plants cespitose or pulvinate, caudex branched; fruits (3-)4-9 (-14) mm; ovules (4-)8-24 per ovary | → 9 |
8. Fruits narrowly elliptic to lanceolate, 2-3.5 mm wide; styles 0.2-0.6(-0.8) mm; racemes (5-)10-35(-47)-flowered; ne Nevada, Utah. | D. brachystylis |
8. Fruits linear to linear-elliptic, 1.5-2 mm wide; styles 0.01-0.15 mm; racemes (2-)4-10(-15)-flowered; Alaska, Alberta, British Columbia, Washington, Yukon. | D. stenoloba |
9. Seeds 1.8-2.8 × 1.2-2 mm, winged. | D. asterophora |
9. Seeds 0.7-1.8 × 0.4-1 mm, not winged | → 10 |
10. Petals white; cauline leaves 1-4; styles (0.7-)1-1.8(-2.1) mm; fruits slightly twisted or plane; e Nevada. | D. pennellii |
10. Petals yellow (or fading white); cauline leaves 1; styles 0.2-0.9 mm; fruits plane; Nevada and elsewhere | → 11 |
11. Fruits flattened; abaxial surface of leaf blades with pectinate and sometime 4-6-rayed trichomes; petals yellow (fading white), 4-6 mm. | D. incerta |
11. Fruits inflated (at least basally); abaxial surface of leaf blades with 2-4-rayed trichomes; petals yellow, 3-4 mm. | D. sobolifera |
12. Caudices simple, plants not cespitose | → 13 |
12. Caudices branched, plants cespitose (branches sometimes surculose or rhizomatous) | → 18 |
13. Petals white; styles 0.03-0.1(-0.15) mm. | D. praealta |
13. Petals yellow, rarely fading whitish; styles (0.5-)0.9-3.5 mm | → 14 |
14. Cauline leaves 1-5; sepals with 2-4-rayed trichomes | → 15 |
14. Cauline leaves 5-33(-43); sepals glabrous or with some simple trichomes | → 16 |
15. Petals (5-)6-8.5 × 2.2-3.5 mm; fruits slightly twisted; ovules 24-36 per ovary; styles (0.8-)1-2.2 mm; se Arizona, w New Mexico. | D. mogollonica |
15. Petals 3-5 × 1-1.5 mm; fruits plane; ovules 14-22 per ovary; styles 0.9-1.2 mm; nc Utah. | D. santaquinensis |
16. Fruits 3-5 mm wide, plane; stems 0.3-1.5 dm; petals 0.5-1(-1.2) mm wide. | D. aureola |
16. Fruits 2-3.5 mm wide, usually twisted, rarely plane; stems (0.5-)1-4.3 (-5.2) dm; petals 1.5-2.5 mm wide | → 17 |
17. Styles 0.5-1.2(-1.5) mm; petals 3.5-5 mm; ovules 28-38(-44) per ovary; fruits often subappressed to rachises. | D. aurea |
17. Styles (1-)1.5-3.5 mm; petals 5-7 mm; ovules 14-28 per ovary; fruits not appressed to rachises. | D. helleriana |
18. Basal and often cauline leaf blade margins dentate; petals white | → 19 |
18. Basal and cauline leaf blade margins usually entire, sometimes denticulate (D. viridis); petals yellow (unknown in D. trichocarpa) | → 21 |
19. Styles (1-)1.5-3(-4) mm (sparsely pubescent); ovules 4-10(-12) per ovary; fruits often strongly twisted. | D. ramosissima |
19. Styles (0.01-)0.1-0.6(-0.8) mm (glabrous); ovules 16-28(-30) per ovary; fruits plane or slightly twisted | → 20 |
20. Petals 4-6 mm; fruits (5-)7-12 × 2.5-4.5 mm, slightly twisted or plane; Alaska, w Canada. | D. borealis |
20. Petals 2.5-4 mm; fruits 4-8 × 2-3 mm, plane; e Canada, Greenland. | D. norvegica |
21. Styles 0.3-1.2(-1.4) mm; ovules 8-12 per ovary; Idaho, Nevada | → 22 |
21. Styles (0.7-)1.2-3.5 mm; ovules 8-24 per ovary; s Arizona, California, s Oregon | → 23 |
22. Basal leaf blades 6-19(-24) × 2-5(-8) mm; styles 0.5-1.2(-1.4) mm; petals 3.5-5 mm; fruiting pedicels (3-)4-8 mm; Nevada. | D. arida |
22. Basal leaf blades 2-4 × 0.5-1.5 mm; styles 0.3-0.7 mm; petals 2-4 mm; fruiting pedicels 1-4.5 mm; Idaho. | D. trichocarpa |
23. Cauline leaves 5-16; fruits 3.5-8 mm; leaf blade surfaces with cruciform trichomes; s Arizona. | D. viridis |
23. Cauline leaves 1-3 (or 4); fruits 6-11(-15) mm; leaf blade surfaces with 2- or 3-rayed trichomes; California, Oregon | → 24 |
24. Petals 5.5-8 mm; cauline leaves 1-3 (or 4); fruits lanceolate to broadly ovate, plane; n California, s Oregon. | D. howellii |
24. Petals 3-3.5 mm; cauline leaves 1; fruits oblong to linear-oblong, slightly twisted or plane; s California. | D. saxosa |
Group 6
1. Branched trichomes sessile, malpighiaceous; Greenland. | D. sibirica |
1. Branched trichomes stalked, not malpighiaceous, sometimes only simple cilia present; not Greenland (except D. crassifolia and D. lactea) | → 2 |
2. Fruits 10-23 mm; seeds orbicular, 3-4.5 mm, broadly winged. | D. carnosula |
2. Fruits 2.5-11(-16) mm; seeds ovoid, oblong, or elliptic, 0.7-2(-2.6) mm, not winged | → 3 |
3. Plants stoloniferous; basal leaves not rosulate. | D. ogilviensis |
3. Plants not stoloniferous (usually cespitose or pulvinate); basal leaves rosulate | → 4 |
4. Petals white | → 5 |
4. Petals yellow (rarely fading white) | → 10 |
5. Petals 5-6.5 mm; styles 0.6-1.8(-2.5) mm; Nevada. | D. serpentina |
5. Petals 2.5-4.5(-5) mm; styles 0.1-0.9(-1.2) mm; not Nevada | → 6 |
6. Fruits inflated (at least basally); racemes (6-)10-28(-40)-flowered. | D. subalpina |
6. Fruits flattened; racemes 2-8(-12)-flowered | → 7 |
7. Ovules (10-)14-22(-26) per ovary; petals 1.8-3 mm wide; Alaska, Canada, Greenland | → 8 |
7. Ovules 8-16 per ovary; petals 1.2-2 mm wide; Idaho, Montana, Utah, Wyoming | → 9 |
8. Petiole and midvein of basal leaves thickened; basal leaves (1-)2-6 mm wide; styles 0.1-0.4 mm. | D. lactea |
8. Petiole and midvein of basal leaves not thickened; basal leaves 1-2 mm wide; styles 0.4-1 mm. | D. mulliganii |
9. Basal leaf blade apex acute; fruits ovate, plane, 2.5-4 mm wide; fruiting pedicels 2-6 mm; sepals persistent. | D. globosa |
9. Basal leaf blade apex obtuse; fruits ± oblong, slightly twisted, 1.5-3 mm wide; fruiting pedicels 4-13 mm; sepals caducous. | D. oreibata |
10. Fruits inflated (at least basally) | → 11 |
10. Fruits flattened | → 12 |
11. Adaxial surface of leaf blades with simple and 2-rayed trichomes; styles 0.1-0.5 mm. | D. macounii |
11. Adaxial surface of leaf blades with 2-4-rayed trichomes; styles 0.3-1(-1.3) mm. | D. sphaeroides |
12. Styles (0.5-)0.7-3 mm; petals (4-)5-8 mm; sepals 2-4 mm | → 13 |
12. Styles 0.02-0.8(-1) mm; petals 1.5-4(-6) mm; sepals 1-3 mm | → 15 |
13. Leaf blade margins ciliate with subsetiform, simple trichomes. | D. burkei |
13. Leaf blade margins not ciliate, often with some branched trichomes | → 14 |
14. Fruits 6-11(-15) × 3-5 mm; styles (0.7-)1.6-3 mm; ovules 8-22 per ovary; California, Oregon. | D. howellii |
14. Fruits (3-)4-6.5(-8) × 2-3.2 mm; styles 0.6-1.7 mm; ovules 4-8 per ovary; Utah. | D. maguirei |
15. Plants without sterile rosettes or shoots, not pulvinate or matted, caudex simple or branched; petals 0.5-1 mm wide; ovules (8-)16-24(-30) per ovary; seeds 0.7-0.8 mm. | D. crassifolia |
15. Plants often with sterile rosettes or shoots, pulvinate or loosely matted, caudex branched; petals 1-3 mm wide; ovules 4-16 per ovary; seeds 1-2(-2.6) mm | → 16 |
16. Fruiting pedicels decurrent basally. | D. incrassata |
16. Fruiting pedicels not decurrent basally | → 17 |
17. Plants loosely matted; racemes considerably elongated in fruit. | D. cruciata |
17. Plants pulvinate; racemes not or slightly elongated in fruit | → 18 |
18. Leaf blades with prominent midvein abaxially; fruit valves pubescent or puberulent. | D. densifolia |
18. Leaf blades with obscure midvein; fruit valves glabrous | → 19 |
19. Leaves fleshy, blade apex obtuse; fruiting pedicels 4-10 mm; fruit valves obscurely veined. | D. daviesiae |
19. Leaves not fleshy, blade apex acute; fruiting pedicels 2-6 mm; fruit valves distinctly veined. | D. globosa |
Group 7
1. Abaxial surface of leaf blades with some 7-16-rayed trichomes | → 2 |
1. Abaxial surface of leaf blades with simple and/or 2-5 (or 6)-rayed or malpighiaceous trichomes | → 9 |
2. Trichomes pectinate; leaf blades with midvein prominent abaxially; fruits inflated (at least basally). | D. oligosperma |
2. Trichomes stellate or, rarely, subdendritic; leaf blades with midvein obscure abaxially (prominent in D. lactea); fruits flattened | → 3 |
3. Leaf blades with midvein strongly thickened abaxially. | D. lactea |
3. Leaf blades with midvein obscure abaxially | → 4 |
4. Petals white, 2-4 mm | → 5 |
4. Petals yellow (white fading yellowish in D. palanderiana), 4-6 mm | → 7 |
5. Fruits linear to narrowly lanceolate or oblong, 6-15(-18) mm; ovules 16-24(-28) per ovary; rachises often slightly flexuous. | D. lonchocarpa |
5. Fruits ovate to oblong, 4-8 mm; ovules 12-16 per ovary; rachises not flexuous | → 6 |
6. Fruits not appressed to rachises; petals 2-3 mm wide; fruiting pedicels (4-)5-9 mm; style 0.4-1 mm. | D. mulliganii |
6. Fruits appressed to rachises; petals 0.7-1.2 mm wide; fruiting pedicels 0.5-2(-4) mm; style 0.05-0.1 mm. | D. porsildii |
7. Ovules 18-32 per ovary; seeds 0.9-1.1 × 0.5-0.7 mm; fruit valves glabrous. | D. palanderiana |
7. Ovules 8-16 per ovary; seeds 1.2-2 × 0.8-1.3 mm; fruit valves often puberulent, sometimes glabrous | → 8 |
8. Styles (0.7-)1-1.8(-2.4) mm; petiole bases and leaf blade margins not ciliate; sepals pubescent, trichomes 4-6-rayed; Idaho. | D. argyrea |
8. Styles 0.5-0.9(-1.1) mm; petiole bases and leaf blade margins ciliate; sepals pubescent, trichomes simple and 2-rayed; Alaska, British Columbia, Washington, Yukon. | D. ruaxes |
9. Leaf blades with malpighiaceous trichomes. | D. sibirica |
9. Leaf blades with simple, forked, stellate, or subdendritic trichomes | → 10 |
10. Abaxial surface of leaf blades with mixture of simple and 2(-4)-rayed trichomes | → 11 |
10. Abaxial surface of leaf blades with 2-6-rayed trichomes | → 18 |
11. Petals yellow (rarely fading white); fruits not inflated basally (flattened) | → 12 |
11. Petals white; fruits inflated basally (flattened in D. fladnizensis) | → 15 |
12. Perennials with poorly developed caudex, not stoloniferous; petals 1.5-3.2 × 0.5-1.2 mm; styles 0.01-0.12 mm; ovules (20-)24-38(-44) per ovary | → 13 |
12. Perennials with branched caudex or stoloniferous; petals 3.5-6 × 2-3.5 mm; styles 0.4-1 mm; ovules 8-20 per ovary | → 14 |
13. Abaxial surface of leaf blades pubescent with 2-4-rayed trichomes; stems pubescent, trichomes simple and 2-4-rayed. | D. albertina |
13. Abaxial surface of leaf blades glabrous or with some simple and 2-rayed trichomes; stems usually glabrous, rarely sparsely pubescent basally, trichomes simple. | D. crassifolia |
14. Plants stoloniferous; basal leaves not rosulate, blades with obscure midvein; fruits oblong, 2-3 mm wide. | D. ogilviensis |
14. Plants not stoloniferous; basal leaves rosulate, blades with prominent, persistent midvein; fruits elliptic to lanceolate, 3-4 mm wide. | D. pilosa |
15. Basal leaf blades with a prominent midvein | → 16 |
15. Basal leaf blades with obscure midvein | → 17 |
16. Fruits flattened, elliptic-lanceolate to oblong, 1.5-2 mm wide; rachises glabrous; petals 2-3.5 mm. | D. fladnizensis |
16. Fruits slightly inflated, ovoid to oblong, 2-3 mm wide; rachises usually pubescent, rarely glabrous; petals 1.5-2(-2.5) mm. | D. subcapitata |
17. Sepals persistent; fruiting pedicels 1-2.5(-4) mm; petals 1.5-2 mm; fruits (2-)3-5 × (1.2-)1.5-2.5 mm; e California. | D. monoensis |
17. Sepals caducous; fruiting pedicels (3-)5-10(-17) mm; petals 3-5 mm; fruits 4-8(-10) × 2.5-4 mm; s Utah. | D. subalpina |
18. Caudex simple or branched, without sterile rosettes; styles 0.01-0.15(-0.2) mm | → 19 |
18. Caudex often branched, with sterile rosettes; styles (0.1-)0.2-3 mm | → 21 |
19. Sepals pubescent with simple and 2- or 3-rayed trichomes; abaxial surface of leaf blades with (2-)4(-6)-rayed trichomes; s Nevada. | D. paucifructa |
19. Sepals glabrous or with simple trichomes; abaxial surface of leaf blades with 2-4-rayed trichomes; not s Nevada | → 20 |
20. Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12(-15) mm. | D. albertina |
20. Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-) 10-17(-20) mm. | D. stenoloba |
21. Abaxial surface of leaf blades with some pectinate or submalpighiaceous trichomes | → 22 |
21. Abaxial surface of leaf blades with cruciform or 2-5-rayed trichomes | → 23 |
22. Abaxial surface of leaf blades with pectinate and some 4-6-rayed trichomes; ovules 8-16(-20) per ovary. | D. incerta |
22. Abaxial surface of leaf blades with submalpighiaceous trichomes; ovules 20-28 per ovary. | D. kassii |
23. Fruits inflated (at least basally) | → 24 |
23. Fruits flattened | → 26 |
24. Styles 0.1-0.5 mm; fruiting pedicels not expanded basally; anthers 0.2-0.3 mm; Alaska, Alberta, British Columbia, Montana, Yukon. | D. macounii |
24. Styles 0.3-1(-1.3) mm; fruiting pedicels usually expanded basally; anthers 0.4-0.5 mm; Nevada, Utah | → 25 |
25. Plants densely pulvinate; petals 2.7-4 mm; fruiting pedicels divaricate- ascending. | D. sphaeroides |
25. Plants loosely cespitose; petals 3.5-5.5 mm; fruiting pedicels divaricate, horizontal, or slightly descending. | D. pedicellata |
26. Seeds 1.8-2.8 × 1.2-2 mm, winged. | D. asterophora |
26. Seeds 0.7-2(-2.6) × 0.4-1(-1.4) mm, not winged | → 27 |
27. Fruits twisted, curved. | D. sharsmithii |
27. Fruits plane, not curved (straight) | → 28 |
28. Leaf blades with prominent midveins, margins ciliate (trichomes simple). | D. densifolia |
28. Leaf blades with obscure midveins, margins not ciliate | → 29 |
29. Fruits 2.5-4.5(-5.5) mm wide; rachises often flexuous; fruiting pedicels expanded basally or not. | D. pedicellata |
29. Fruits 1.5-3 mm wide; rachises not flexuous; fruiting pedicels not expanded basally | → 30 |
30. Ovules 4-10(-12) per ovary; seeds 0.8-1.3 mm wide | → 31 |
30. Ovules 12-30 per ovary; seeds 0.4-0.8 mm wide | → 32 |
31. Styles (0.1-)0.3-0.8 mm; petals 4-5(-6) × 1.2-2 mm; sepals 1.5-2 mm; ec California. | D. cruciata |
31. Styles 0.6-1.7 mm; petals 5-7 × 2-3 mm; sepals 2.5-4 mm; n Utah. | D. maguirei |
32. Abaxial surface of leaf blades pubescent, trichomes cruciform; racemes (2-)4-13(-18)-flowered; petals 3-5 mm; Alaska, Alberta, British Columbia, Northwest Territories, Yukon. | D. juvenilis |
32. Abaxial surface of leaf blades pubescent, trichomes (2-)4 (or 5)-rayed; racemes 14-36-flowered; petals 5-6 mm; sw Utah. | D. zionensis |
Group 8
1. Abaxial surface of leaf blades with pectinate, subpectinate, subdendritic, or stellate with 7-16-rayed trichomes | → 2 |
1. Abaxial surface of leaf blades with simple, cruciform, or 2-4(-6)-rayed trichomes | → 12 |
2. Leaves, pedicels, and sepals with sessile or subsessile, pectinate trichomes | → 3 |
2. Leaves, pedicels, and sepals with stalked, stellate to subdendritic trichomes | → 5 |
3. Fruit valves pubescent, trichomes pectinate; ovules 4-8 per ovary. | D. pectinipila |
3. Fruit valves glabrous or pubescent, trichomes simple or 2-rayed; ovules (6-)8-16 (-20) per ovary | → 4 |
4. Fruits 5-9(-11) mm, flattened; petals 4-6 mm; sepals 2.5-3.5(-4) mm; leaf midvein usually obscure. | D. incerta |
4. Fruits 3-6(-7) mm, inflated; petals 2.5-4 mm; sepals 1.5-3 mm; leaf midvein prominent. | D. oligosperma |
5. Petals white or creamy white | → 6 |
5. Petals yellow | → 9 |
6. Sepals caducous; fruit valves glabrous; Alaska, Northwest Territories, Yukon | → 7 |
6. Sepals persistent; fruit valves usually pubescent, rarely glabrous (D. californica); e California, w Nevada | → 8 |
7. Stems pubescent throughout, trichomes 8-15-rayed; petals spatulate to oblanceolate, 2-3.5 × 0.8-1.4 mm; rachises and fruiting pedicels pubescent; styles 0.1-0.4 mm. | D. nivalis |
7. Stems pubescent proximally, trichomes 2-9-rayed; petals obovate, 4.4-5.5 × 2-3 mm; rachises and fruiting pedicels usually glabrous, rarely sparsely pubescent; styles 0.3-0.8 mm. | D. palanderiana |
8. Fruits usually twisted, rarely plane, with 2-5-rayed trichomes; fruiting pedicels 1.5-3(-4) mm. | D. breweri |
8. Fruits plane, with simple and 2- or 3-rayed trichomes, rarely glabrous; fruiting pedicels (2-)4-9(-12) mm. | D. californica |
9. Fruits 4-11 mm, flattened, twisted or plane | → 10 |
9. Fruits 2-5(-6) mm, inflated (at least basally), plane | → 11 |
10. Styles (0.7-)1-1.8(-2.4) mm; fruits symmetric; fruiting pedicels (4-) 5-12(-19) mm; c Idaho. | D. argyrea |
10. Styles (0.1-)0.3-0.7(-1) mm; fruits often asymmetric; fruiting pedicels 2-5(-7) mm; ec California. | D. sierrae |
11. Racemes (4-)6-18(-23)-flowered, elongated in fruit; petals 4-6 mm; fruiting pedicels 4-9(-13) mm; c Idaho. | D. sphaerocarpa |
11. Racemes 2-5(-10)-flowered (subumbellate), not or slightly elongated in fruit; petals 2.8-4 mm; fruiting pedicels 1.5-3(-6) mm; e California, w Nevada. | D. subumbellata |
12. Plants stoloniferous; basal leaves not rosulate. | D. ogilviensis |
12. Plants not stoloniferous (usually cespitose); basal leaves usually rosulate | → 13 |
13. Petals white | → 14 |
13. Petals yellow | → 16 |
14. Sepals persistent; fruits slightly inflated basally; petals 1.5-2 × 0.5-0.6 mm. | D. monoensis |
14. Sepals caducous; fruits flattened; petals 2-6 × 0.8-2.8 mm | → 15 |
15. Styles 0.1-0.7 mm; fruit valves usually glabrous, rarely pubescent, trichomes simple (along margin); Alaska, Alberta, British Columbia, Northwest Territories, Yukon. | D. juvenilis |
15. Styles (0.7-)1-1.8(-2.1) mm; fruit valves with simple and 2-rayed trichomes; e Nevada. | D. pennellii |
16. Abaxial surface of leaf blades with cruciform trichomes; ovules 16-30 per ovary. | D. juvenilis |
16. Abaxial surface of leaf blades with 2-6-rayed trichomes; ovules 4-18(-22) per ovary | → 17 |
17. Racemes (15-)30-75-flowered; Arizona. | D. asprella |
17. Racemes 3-20(-27)-flowered; not Arizona | → 18 |
18. Styles (0.7-)1.6-3 mm; petals 5.5-8 mm; anthers 0.7-0.9 mm. | D. howellii |
18. Styles 0.3-1.4 mm; petals 3.5-5.5(-6) mm; anthers 0.4-0.6 mm | → 19 |
19. Fruit valves glabrous or pubescent, trichomes simple and 2-rayed; fruiting pedicels usually expanded basally | → 20 |
19. Fruit valves pubescent, trichomes 2-6-rayed; fruiting pedicels not expanded basally | → 21 |
20. Petals 3.5-5.5 mm; fruiting pedicels horizontal to divaricate; ovules 8-16 per ovary. | D. pedicellata |
20. Petals 2.7-4 mm; fruiting pedicels divaricate-ascending; ovules 4-10 (-12) per ovary. | D. sphaeroides |
21. Fruits flattened, 2-4.5 mm wide, 10-18-seeded; styles 0.4-0.8(-1) mm; racemes 10-20(-25)-flowered; surface of leaf blades pubescent with (2-) 4-rayed trichomes; se Oregon. | D. cusickii |
21. Fruits inflated basally, 3.5-5 mm wide, 8-12-seeded; styles (0.5-)0.7-1.4 mm; racemes 5-10(-16)-flowered; surface of leaf blades pubescent with 2-6-rayed trichomes; Alberta, British Columbia, Colorado, Utah, Wyoming, Yukon. | D. ventosa |
Group 9
1. Abaxial surface of leaf blades usually with simple and/or 2-rayed trichomes, rarely glabrous | → 2 |
1. Abaxial surface of leaf blades with simple and 2-6-rayed trichomes, sometimes subdendritic and up to 12-rayed | → 8 |
2. Sepals persistent | → 3 |
2. Sepals caducous | → 4 |
3. Petals yellow, 3.5-5 × 1.5-2 mm; styles 0.4-1 mm; fruiting pedicels 3-7 mm; fruits 2.5-5 mm wide, flattened. | D. longisquamosa |
3. Petals white, 1.5-2 × 0.5-0.6 mm; styles 0.1-0.2 mm; fruiting pedicels 1-2.5(-4) mm; fruits (1.2-)1.5-2.5 mm wide, slightly inflated basally. | D. monoensis |
4. Abaxial surface of leaf blades glabrous, midvein prominent; plants pulvinate. | D. densifolia |
4. Abaxial surface of leaf blades usually pubescent, sometimes glabrous (D. cyclomorpha), midvein usually obscure (except D. subcapitata); plants often not pulvinate | → 5 |
5. Petals 1.4-4 × 0.5-1 mm; racemes 1-8 (or 9)-flowered, not or slightly elongated in fruit; Alaska, Canada, Greenland | → 6 |
5. Petals 4-6 × 1.5-2.5 mm; racemes 4-15(-21)-flowered, elongated in fruit; California, Oregon | → 7 |
6. Petals yellow or yellowish green, linear-oblanceolate, 3-4 × 0.5-0.8 mm; leaf blades each with midvein usually obscured; ovules 4-8 per ovary; Alaska. | D. aleutica |
6. Petals white or creamy white, spatulate, 1.5-2(-2.5) × 0.7-1 mm; leaf blades each with midvein strongly thickened; ovules 14-24 per ovary; Alaska, Greenland, Northwest Territories, Nunavut, Quebec. | D. subcapitata |
7. Fruits plane, valves glabrous; fruiting pedicels softly pilose; ovules 8-12 per ovary; seeds 1.4-1.9 × 1-1.2 mm; ne Oregon. | D. cyclomorpha |
7. Fruits slightly twisted, valves pubescent; fruiting pedicels hirsute; ovules 10-16 per ovary; seeds 1-1.4 × 0.6-1 mm; ec California. | D. lemmonii |
8. Racemes not or slightly elongated (sometimes subumbellate) in fruit | → 9 |
8. Racemes elongated in fruit | → 13 |
9. Abaxial surface of leaf blades with 2-5-rayed trichomes; fruit valves glabrous; petals 1-2 mm wide. | D. macounii |
9. Abaxial surface of leaf blades with some simple trichomes; fruit valves pubescent or puberulent (sometimes glabrous in D. stenopetala and D. subcapitata); petals 0.3-1.5 mm wide | → 10 |
10. Basal leaves densely imbricate; fruits 3-6 mm, inflated (at least basally) | → 11 |
10. Basal leaves not imbricate; fruits 5-10 mm, flattened | → 12 |
11. Petals usually yellow, rarely purple, linear, 2.5-5 × 0.3-0.7 mm; ovules 4-10 per ovary. | D. stenopetala |
11. Petals white or creamy white, spatulate, 1.5-2(-2.5) × 0.7-1 mm; ovules 14-24 per ovary. | D. subcapitata |
12. Fruits ovate-elliptic, 2-3.2 mm wide, valves often densely pubescent; ovules (16-)18-28 per ovary; leaf blades with apices obtuse to rounded, surfaces with subcruciform trichomes. | D. micropetala |
12. Fruits obovate, (3-)3.5-5 mm wide, valves often glabrate; ovules 8-16 (-20) per ovary; leaf blades with apices acute or subacute, surfaces with simple and/or 2-branched trichomes. | D. pauciflora |
13. Plants stoloniferous; basal leaves not rosulate; fruit valves glabrous. | D. ogilviensis |
13. Plants cespitose, not stoloniferous; basal leaves rosulate; fruit valves pubescent or glabrous | → 14 |
14. Petals linear, 0.3-0.7 mm wide; fruits inflated basally; ovules 4-10 per ovary. | D. stenopetala |
14. Petals obovate, spatulate, or narrowly oblanceolate, (0.7-)1-4.6 mm wide; fruits flattened; ovules 12-36 per ovary | → 15 |
15. Petals white; fruit valves pubescent, trichomes 2-5-rayed; stigmas distinctly wider than styles; abaxial surface of leaf blades with some 6-12-rayed trichomes | → 16 |
15. Petals pale or bright yellow (sometimes creamy white in D. oxycarpa); fruit valves usually pubescent, sometimes glabrous, trichomes simple, spurred, or 2-rayed; stigmas about as wide as styles; abaxial surface of leaf blades with 2-5-rayed trichomes (rays sometimes spurred in D. oxycarpa) | → 17 |
16. Fruits with 2-4-rayed and, sometimes, simple trichomes; petals 3-4 mm; stems proximally with branched trichomes 2-6-rayed. | D. arctogena |
16. Fruits with (2-)5-12-rayed trichomes; petals 3.5-5 mm; stems proximally with branched trichomes 4-10-rayed. | D. oblongata |
17. Fruiting pedicels 1-3(-4) mm; petals 2-3 × (0.7-)1-1.5 mm; styles 0.05- 0.3 mm; racemes slightly elongated in fruit. | D. micropetala |
17. Fruiting pedicels (2.5-)4-13(-30) mm; petals 3.5-6 × 1.7-4.6 mm; styles (0.1-)0.2-0.9 mm; racemes often considerably elongated in fruit | → 18 |
18. Basal leaf blades linear to linear-oblanceolate, 1-2.5(-4) mm wide, midveins prominent. | D. pilosa |
18. Basal leaf blades oblong, lanceolate, oblanceolate, or obovate, 2-9 mm wide, midveins obscure | → 19 |
19. Petals 1.7-2.5 mm wide; sepals purplish tinged; fruits elliptic; abaxial surface of leaf blades with 2-4-rayed trichomes; seeds pale brown. | D. alpina |
19. Petals 2.5-4.6 mm wide; sepals gray-green; fruits ovate, ovate-oblong, or lanceolate; abaxial surface of leaf blades with 2-5-rayed and subdendritic trichomes; seeds dark brown or black | → 20 |
20. Basal leaf blade margins usually denticulate; fruits ovate to ovate-oblong, 3-5 mm wide; styles 0.2-0.6 mm; Greenland. | D. oxycarpa |
20. Basal leaf blade margins entire; fruits lanceolate, 2.3-3.8 mm wide; styles 0.1-0.3 mm; Canada. | D. simmonsii |
Group 10
1. Abaxial surface of leaf blades with pectinate, subdendritic, or some 7-12-rayed, stellate trichomes | → 2 |
1. Abaxial surface of leaf blades with 2-6-rayed trichomes | → 14 |
2. Styles 1.5-3(-3.8) mm; seeds winged; anthers 0.7-0.9 mm. | D. pterosperma |
2. Styles (0.05-)0.1-1(-1.2) mm; seeds not winged; anthers 0.2-0.7 mm | → 3 |
3. Abaxial surface of leaf blades with some pectinate trichomes | → 4 |
3. Abaxial surface of leaf blades with stellate or subdendritic trichomes | → 5 |
4. Fruits 5-9(-11) mm, flattened; petals 4-6 mm; sepals 2.5-3.5(-4) mm; leaf blades usually with obscure midveins. | D. incerta |
4. Fruits 3-6(-7) mm, inflated; petals 2.5-4 mm; sepals 1.5-3 mm; leaf blades with prominent midveins. | D. oligosperma |
5. Fruit valves pubescent, trichomes 2-6-rayed | → 6 |
5. Fruit valves glabrous or pubescent to puberulent, trichomes primarily simple and 2-rayed | → 9 |
6. Plants not pulvinate; leaf blades 0.4-2.3(-3) cm × 1-6.5 mm; petals white; ovules 20-42 per ovary | → 7 |
6. Plants pulvinate; leaf blades 0.2-0.8 cm × 0.5-1.5(-2) mm; petals yellow; ovules 4-12(-16) per ovary | → 8 |
7. Basal leaf blades apically with simple trichomes, midveins distinct abaxially; seeds 0.8-1.1 × (0.6-)0.7-0.8 mm. | D. arctica |
7. Basal leaf blades apically without simple trichomes, midveins obscure abaxially; seeds 0.6-0.8 × 0.4-0.6 mm. | D. cinerea |
8. Fruits inflated basally (symmetric), plane, (2.5-)3-4(-5) mm; Alberta, British Columbia, California, Montana, Utah, Wyoming. | D. novolympica |
8. Fruits flattened (asymmetric), twisted or plane, 4-8(-10) mm; ec California. | D. sierrae |
9. Seeds 1.5-2.2 × 1-1.4 mm; fruits 3-5 mm wide; styles 0.5-1.2 mm; petals yellow; ovules 8-16 per ovary | → 10 |
9. Seeds 0.7-1.3 × 0.5-0.8 mm; fruits 1-2.5(-3) mm wide (-5 mm wide in D. oxycarpa); styles 0.05-0.6(-1 in D. scotteri) mm; petals white or creamy white (yellow in D. scotteri and, sometimes, D. oxycarpa); ovules (10-) 12-28 per ovary | → 11 |
10. Leaf blades each with prominent midvein; basal blades linear to linear-oblanceolate, 0.8-1.5 mm wide; petals pale yellow; fruits slightly inflated basally; w Montana, nw Wyoming. | D. paysonii |
10. Leaf blades each with obscure midvein; basal blades oblanceolate to obovate or suborbicular, 2-4.5 mm wide; petals bright yellow; fruits flattened; Alaska, British Columbia, Washington, Yukon. | D. ruaxes |
11. Rachises often slightly flexuous; petals 2-3.5 × 1-1.5 mm; fruits linear to narrowly lanceolate or narrowly oblong, slightly twisted or plane. | D. lonchocarpa |
11. Rachises not flexuous; petals 3-5.5 × 1.5-3.5 mm; fruits ovate, oblong, lanceolate, or broadly so, rarely narrowly lanceolate, plane | → 12 |
12. Fruits 3-5 mm wide; fruiting pedicels often curved upwards; leaf blade margins usually denticulate. | D. oxycarpa |
12. Fruits 1.5-3 mm wide; fruiting pedicels straight; leaf blade margins usually entire, rarely denticulate (D. lactea) | → 13 |
13. Petals white; fruits 4-8 mm, valves glabrous. | D. lactea |
13. Petals yellow; fruits 5-11 mm, valves pubescent. | D. scotteri |
14. Ovules (16-)18-36 per ovary | → 15 |
14. Ovules 4-14(-16) per ovary | → 20 |
15. Styles (0.8-)1.2-3.5 mm; racemes 12-43-flowered; s California. | D. saxosa |
15. Styles 0.01-0.7 mm; racemes 2-12(-23)-flowered; Alaska, Canada, Greenland | → 16 |
16. Fruits linear to linear-elliptic, (8-)10-17(-20) × 1.5-2 mm; plants not cespitose, caudex simple. | D. stenoloba |
16. Fruits oblong, ovate, or lanceolate, 4-12 × 2-5.5 mm; plants often cespitose, caudex branched | → 17 |
17. Leaf blade margins entire | → 18 |
17. Leaf blade margins dentate or denticulate | → 19 |
18. Petals 4-6 × 3-5 mm; fruits 3.5-5.5 mm wide (stigmas distinctly wider than styles); racemes not elongated (corymbose) in fruit. | D. corymbosa |
18. Petals 2-3 × (0.7-)1-1.5 mm; fruits 2-3.2 mm wide (stigmas narrower than styles); racemes mostly elongated in fruit. | D. micropetala |
19. Fruits oblong to lanceolate-elliptic, 4-8 × 2-3 mm; fruiting pedicels straight, suberect to ascending, often subappressed to rachises; petals white, 2.5-4 mm. | D. norvegica |
19. Fruits ovate to ovate-oblong, 5-10 × 3-5 mm; fruiting pedicels curved upwards, subhorizontal to divaricate-ascending, not appressed to rachises; petals yellow or creamy white, 3.5-5 mm. | D. oxycarpa |
20. Fruits inflated (at least basally), usually ovoid, subglobose, or ellipsoid, rarely lanceolate | → 21 |
20. Fruits flattened, ovate, lanceolate, oblong, or elliptic | → 25 |
21. Leaf blades (1-)2-4(-6) mm wide; fruit valves glabrous or pubescent, trichomes simple and 2(-4)-rayed | → 22 |
21. Leaf blades 0.5-1.5 mm wide; fruit valves pubescent, trichomes 2-6-rayed | → 23 |
22. Racemes 3-10(-13)-flowered; fruiting pedicels horizontal to divaricate, curved, glabrous (at least adaxially); ovules 10-16 per ovary; Alaska, Alberta, British Columbia, Montana, Yukon. | D. macounii |
22. Racemes (5-)9-18(-23)-flowered; fruiting pedicels divaricate-ascending, usually straight, rarely curved, pubescent; ovules (4-)8-12 per ovary; sc Utah. | D. sobolifera |
23. Adaxial surface of leaf blades with simple and 4-6-rayed trichomes; fruit valves with 4-rayed trichomes (some rays spurred). | D. trichocarpa |
23. Adaxial surface of leaf blades with simple and 2-rayed trichomes; fruit valves with 2-6-rayed and simple trichomes | → 24 |
24. Fruits (2.5-)3-4(-5) × 1.5-3.5 mm; petals bright yellow, 2-3.5(-4) mm; styles 0.2-0.6(-0.8) mm. | D. novolympica |
24. Fruits (5-)6-9 × (3-)3.7-5 mm; petals pale yellow, (4-)5-6 mm; styles (0.6-)0.8-1.2 mm. | D. paysonii |
25. Abaxial surface of leaf blades with only 2-rayed trichomes. | D. lemmonii |
25. Abaxial surface of leaf blades glabrous or with 2-4-rayed and simple trichomes | → 26 |
26. Adaxial surface of leaf blades pubescent with simple and 2-4-rayed trichomes | → 27 |
26. Adaxial surface of leaf blades glabrous (at least proximally), usually pubescent distally with simple trichomes | → 29 |
27. Styles (0.8-)1.2-3.5 mm; petals linear-oblanceolate, 0.5-1 mm wide; racemes 12-43-flowered; s California. | D. saxosa |
27. Styles 0.2-0.9(-1.1) mm; petals obovate, 2-3.5 mm wide; racemes 2-10 (-14)-flowered; Alaska, Canada, Greenland, Washington | → 28 |
28. Racemes (corymbose) not or slightly elongated in fruit; fruits 6-12 mm; seeds 1-1.3 × 0.6-0.9 mm. | D. corymbosa |
28. Racemes elongated in fruit; fruits 4-8(-10) mm; seeds 1.5-2 × 1-1.3 mm. | D. ruaxes |
29. Styles 0.3-0.6(-1) mm; petals pale yellow, 2-5 mm; leaf blades each with prominent midvein. | D. densifolia |
29. Styles (0.8-)1-4.5 mm; petals white, 4.5-6.5 mm; leaf blades each with obscure midvein | → 30 |
30. Styles (0.8-)1-1.7(-2) mm; leaf blades oblong-linear to narrowly oblanceolate, 1-2 mm wide; anthers ovate, 0.5-0.6 mm; c Idaho. | D. hitchcockii |
30. Styles (1.2-)2-4(-4.5) mm; leaf blades oblanceolate to obovate, 1.5-3.5 mm wide; anthers oblong, 0.8-1 mm; s Nevada. | D. jaegeri |
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