Minuartia uniflora
Minuartia
one-flower stitchwort
sandwort, stitchwort
filiform.
filiform to stout and woody, perennial plants often with branched caudex or with rhizomes or trailing stems.
erect to ascending, green, 7–20 cm, glabrous, internodes of stems 1–7 times as long as leaves.
ascending to erect or prostrate, simple or branched, ± terete.
not overlapping, connate proximally, with tight, herbaceous or scarious sheath 0.1–0.3 mm;
blade straight to outwardly curved, widely spreading, green, flat, 1-veined abaxially, especially proximal, narrowly lanceolate to oblong, commonly linear, 2–20 × 0.3–1.5 mm, flexuous, margins not thickened, scarious, smooth, apex green to purple, rounded to acute, dull, glabrous;
axillary leaves poorly developed.
mostly connate proximally, petiolate (M. cumberlandensis, M. godfreyi proximal leaves) or sessile;
blade 1–3-veined, sometimes obscurely so, filiform-linear to subulate, lanceolate or oblanceolate, rarely to ovate, herbaceous to succulent, apex blunt, rounded, or obtuse to acute, acuminate, or spinescent.
7–25+-flowered, open cymes;
bracts subulate to ovate, herbaceous, margins scarious.
terminal, open or seldom congested cymes or flowers solitary and terminal or axillary, rarely absent;
bracts paired, herbaceous or scarious, rarely absent (M. pusilla, M. rossii).
0.5–5 cm, glabrous.
erect to arcuate-spreading, rarely reflexed (M. drummondii) in fruit.
hypanthium disc-shaped;
sepals obscurely veined, ovate to elliptic or lanceolate (herbaceous portion elliptic to lanceolate), 2–3.5 mm, not enlarging in fruit, apex green, obtuse to rounded, not hooded, glabrous;
petals oblanceolate to spatulate, 1.5–2.5 times as long as sepals, apex rounded, entire to shallowly notched.
perianth and androecium perigynous;
hypanthium usually disc-, occasionally dish- or cup-shaped;
sepals 5, distinct, green (herbaceous portion purple in M. arctica, M. macrocarpa, and M. rossii), linear, lanceolate, or oblong to elliptic, ovate, or broadly ovate, 1.5–6(–9) mm, margins herbaceous or silvery and scarious, apex rounded or obtuse to acute, acuminate, or spinescent, sometimes hooded;
petals 5 or rarely absent, white, rarely pink (M. biflora) or lilac (M. marcescens), clawed (M. glabra, M. groenlandica) or not, blade apex entire, emarginate, or notched;
nectaries 5, at base of filaments opposite sepals, sometimes prominent and 2-lobed;
stamens 10 (8–10 in M. godfreyi), arising from hypanthium;
filaments distinct;
staminodes absent;
styles 3 (to 4 in M. cumberlandensis, M. godfreyi), filiform, 0.6–2.5 mm, glabrous proximally;
stigmas 3 (to 4 in M. cumberlandensis, M. godfreyi), linear along adaxial surface of styles, minutely papillate (30x).
on stipe shorter than 0.1 mm, pyramidal-ovoid, 3.5–4 mm, longer than sepals.
ovoid to broadly ellipsoid or rarely globose, opening by 3 incurved or erect to recurved valves;
carpophore absent or sometimes present.
yellowish brown, suborbiculate with radicle obscure, slightly compressed, 0.4–0.6 mm, tuberculate;
tubercles low, rounded.
1–25, reddish brown to brown or black (or rarely yellowish or purplish brown), spherical or suborbiculate to reniform or obliquely triangular, plump or variously compressed, smooth, reticulate, tuberculate, muriculate-papillate, or rarely with long marginal papillae (M. macrocarpa), marginal wing absent (present in M. douglasii), appendage absent.
= 7, 9, 10, 12, 13, 14, 15, 23.
= 14.
Minuartia uniflora
Minuartia
Minuartia alabamensis was originally described to accommodate much-reduced plants from Alabama (J. F. McCormick et al. 1971). Subsequent studies have shown them to be conspecific with M. uniflora (R. Wyatt 1984).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species ca. 175 (33 in the flora).
The nectaries in Minuartia flowers are often enlarged (to 0.5 mm) and variously lobed; they may not be apparent in fruiting material, possibly due to resorption by the developing flower following pollination. The hypanthium varies from disc- to cup-shaped and ranges in size from less than 1 mm to 3 to 4 mm in diameter (measured on the curve if cup-shaped). The cup-shaped hypanthium is best developed in fruiting material of M. arctica, M. obtusiloba, and relatives.
Minuartia is the second largest genus of Caryophyllaceae in our flora. It is the largest that here includes strictly native taxa. Of the eight genera with ten or more species, only Eremogone also is represented solely by native species.
J. McNeill (1962) outlined an infrageneric classification of Minuartia that included four subgenera and 12 sections within subg. Minuartia; our 33 species would be distributed among seven of those 12 sections. While we follow McNeill (1962, 1980b) in recognizing Arenaria and Minuartia, we have chosen not to adopt his hierarchy formally. Some of his groups do appear to represent natural assemblages; others do not. One of the latter includes most of the Minuartia species native to the southeastern United States. McNeill (1962) placed these species in sect. Uninerviae (Fenzl) Mattfeld; J. Mattfeld (1922) divided them among three series within that section; Á. Löve and D. Löve (1975) segregated two species as the genus Porsildia. There has been no thorough subsequent study of the entire group that could further resolve the question. Molecular investigation of Minuartia (M. Nepokroeff et al. 2001) suggested that it is not monophyletic. One or more of the various segregate genera that have been proposed, originally based on morphological features, with some resurrected by Löve and Löve on cytological grounds, and that are now in use (e.g., Alsinanthe, Alsinopsis, Lidia, Minuopsis, Tryphane; W. A. Weber and R. C. Wittmann 1992) may prove to be supported by dna analysis as well.
Minuartia rossii, a densely pulvinate plant of moist arctic areas, may be difficult to identify in the key since flowers are often absent, especially in northern populations. Vegetative reproduction via easily detached axillary fascicles in the upper leaf axils is more common in these plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants annual, not cespitose, rarely mat-forming | → 2 |
1. Plants perennial, often cespitose, pulvinate, or mat-forming | → 17 |
2. Sepal apices obtuse or merely acutish | → 3 |
2. Sepal apices acuminate to distinctly acute | → 8 |
3. Pedicels stipitate-glandular | → 4 |
3. Pedicels glabrous | → 6 |
4. Sepals 1-3-veined; seeds compressed, winged | M. douglasii |
4. Sepals obscurely veined; seeds somewhat compressed, not winged | → 5 |
5. Leaf blades glabrous; seeds 0.7-0.8 mm, orbiculate, echinate; sc United States | M. drummondii |
5. Leaf blades stipitate-glandular; seeds 1.4-1.7 mm, suborbiculate, low-tuberculate; California, Oregon | M. howellii |
6. Sepals 1- or 3-veined, 2.5-2.8 mm; petals not clawed; California, Oregon | M. californica |
6. Sepals obscurely veined, 1.5-4 mm; petals clawed or not; e United States | → 7 |
7. Petals broadly obovate, clawed; seeds 0.5-0.8 mm, obliquely triangular with adaxial groove | M. glabra |
7. Petals oblanceolate to spatulate, not clawed; seeds 0.4-0.6 mm, suborbiculate, not grooved | M. uniflora |
8. Sepals obscurely veined; leaves stipitate-glandular | M. howellii |
8. Sepals 1-5-veined, often prominently so; leaves glabrous or seldom stipitate-glandular | → 9 |
9. Pedicels glabrous | → 10 |
9. Pedicels stipitate-glandular, sometimes sparsely so | → 13 |
10. Leaves obscurely veined; petals 0.5-1 times as long as sepals or absent | M. pusilla |
10. Leaves 1-3-veined; petals 1-2.2(-3) times as long as sepals | → 11 |
11. Leaves weakly 1-veined abaxially; sepals 1- or 3-veined, apex rounded to acute | M. californica |
11. Leaves 1-veined abaxially; sepals prominently 3-5-veined, apex acute to acuminate | → 12 |
12. Sepals 3(-5)-veined; petals 1-1.5 times as long as sepals; capsules equaling or longer than sepals; California, Oregon | M. cismontana |
12. Sepals (3-)5-veined; petals 1.5-2.2(-3) times as long as sepals; capsules usually shorter than sepals; se and c United States | M. patula |
13. Petal apices entire, w United States | → 14 |
13. Petal apices emarginate or notched; se and c United States | → 15 |
14. Seeds 1.3-2 mm, winged | M. douglasii |
14. Seeds 0.4-0.6 mm, not winged | M. tenella |
15. Flowering stems arising from slender wintering stems; inflorescences 3-5(-7)-flowered; petals oblong-spatulate | M. godfreyi |
15. Wintering stems absent; inflorescences 5-50+-flowered; petals obovate | → 16 |
16. Sepals 3-veined, apex acute; leaf blades linear-lanceolate to oblanceolate, (0.6-)1.5-3.2 mm wide; seeds black, muriculate-papillate | M. muscorum |
16. Sepals (3- or) 5-veined, apex acute or acuminate; leaf blades linear, 0.5-1.5(-1.8) mm wide; seeds reddish brown to black, tuberculate | M. patula |
17. Sepal apices broadly obtuse or rounded | → 18 |
17. Sepal apices acute to acuminate or spinescent | → 31 |
18. Stems pubescent, at least distally, often stipitate-glandular | → 19 |
18. Stems glabrous | → 24 |
19. Leaf blade apices acuminate-pungent; stems 10-30 cm; inflorescences 3-13-flowered | M. yukonensis |
19. Leaf blade apices rounded to truncate; stems 1-12 cm; inflorescences 1-5-flowered | → 20 |
20. Leaf blades flat, obscurely 1- or 3-veined | → 21 |
20. Leaf blades 3-angled or rounded 3-angled, obscurely or prominently 1- or 3-veined | → 22 |
21. Inflorescences with flowers solitary; capsules narrowly ellipsoid, 10-18 mm; seeds ringed with elongate papillae | M. macrocarpa |
21. Inflorescences 3-5-flowered; capsules broadly ellipsoid, 5.5 mm; seeds smooth or obscurely sculptured | M. biflora |
22. Axillary leaves absent; leaf blades obscurely 1-veined; seeds 1.2-1.6 mm, brown, minutely tuberculate | M. arctica |
22. Axillary leaves present among vegetative leaves; leaf blades 1- or 3-veined abaxially; seeds 0.6-1.2 mm, brown or reddish tan, smooth or obscurely sculptured | → 23 |
23. Capsules 6-10 mm; seeds 0.9-1.2 mm, brown | M. marcescens |
23. Capsules 3.5-6 mm; seeds 0.6-0.7 mm, reddish tan | M. obtusiloba |
24. Stems 8-28 cm; inflorescences 5-12+-flowered; sepals broadly ovate | M. caroliniana |
24. Stems 1-10(-20) cm; inflorescences 1-5-flowered; sepals linear to ovate or obovate | → 25 |
25. Petals with apex emarginate or notched, petals 1.4-2.2 times as long as sepals; inflorescences 2-5(-7)-flowered cymes or flowers solitary | → 26 |
25. Petals with apex entire, petals 0.8-2 times as long as sepals (sometimes absent); inflorescences with flowers solitary | → 28 |
26. Pedicels stipitate-glandular | M. biflora |
26. Pedicels glabrous | → 27 |
27. Leaf blades (10-)20-30(-40) × 1-3 mm, linear-oblanceolate to linear-spatulate; inflorescences 1(-3)-flowered | M. cumberlandensis |
27. Leaf blades 4-12(-15) × 0.5 mm, ± linear; inflorescences 3-5-flowered | M. groenlandica |
28. Leaf blades 3-veined, often prominently so abaxially; capsules narrowly ellipsoid, 10-18 mm | M. macrocarpa |
28. Leaf blades 1-veined; capsules spherical or ellipsoid, 1.5-4 mm | → 29 |
29. Stems 1-3 cm; sepals 1-veined | M. rossii |
29. Stems 3-15 cm; sepals 3-veined | → 30 |
30. Sepals, linear to lanceolate; petals rudimentary or absent | M. austromontana |
30. Sepals, ovate to lanceolate; petals 0.8-1 times as long as sepals | M. elegans |
31. Petals 2.5-3 times as long as sepals, apex shallowly notched | M. godfreyi |
31. Petals with apex entire, if slightly emarginate, then petals 0.7-0.9 times as long as sepals, or absent | → 32 |
32. Pedicels stipitate-glandular | → 33 |
32. Pedicels glabrous | → 37 |
33. Stems cespitose to mat-forming; taproot not woody, filiform to somewhat thickened, rhizomes or trailing stems absent; seeds 0.4-0.5 mm | M. rubella |
33. Stems mat-forming; taproot woody, stout; rhizomes, stolons, or trailing stems present; seeds 1.5-2.7 mm | → 34 |
34. Plants densely stipitate-glandular throughout; w North America | M. nuttallii |
34. Plants sparsely stipitate-glandular on pedicels and sepals; California | → 35 |
35. Petals 0.7-0.9 times as long as sepals; stems and leaves green | M. decumbens |
35. Petals 1.4-2.2 times as long as sepals; stems and leaves glaucous or gray-green | → 36 |
36. Stems and leaves glaucous, proximal leaves longer than internodes | M. rosei |
36. Stems and leaves gray-green, proximal leaves often shorter than internodes | M. stolonifera |
37. Petals 1.1-2 times as long as sepals | → 38 |
37. Petals 0.5-1 times as long as sepals, rudimentary or absent | → 40 |
38. Leaf blades 1-4 mm, 3-angled, 1-veined; sepals 1-veined; high arctic | M. rossii |
38. Leaf blades 5-30 mm, flat to 3-angled, 1-3 veined; sepals 3-veined | → 39 |
39. Leaf blades flat to navicular, apex blunt to pungent; inflorescences 5-30-flowered; Great Plains and east | M. michauxii |
39. Leaf blades navicular, apex rounded; inflorescences 1- or 2-5(-8)-flowered; Great Basin and Rocky Mountains | M. macrantha |
40. Inflorescences with flowers solitary, terminal | → 41 |
40. Inflorescences with flowers solitary and terminal or often 2-5(-15)-flowered | → 42 |
41. Sepals linear to lanceolate; petals rudimentary or absent | M. austromontana |
41. Sepals ovate to lanceolate; petals 0.8-1 times as long as sepals | M. elegans |
42. Sepals 3.5-5 mm, to 5.5 mm in fruit; seeds 0.7-1 mm | M. macrantha |
42. Sepals (1.5-)2.5-3.2 mm, to 4 mm in fruit; seeds 0.4-0.6 mm. [43. Shifted to left margin.—Ed.] | → 43 |
43. Inflorescences 7-15-flowered (rarely fewer); seeds dark brown to black, 0.5-0.6 mm | M. dawsonensis |
43. Inflorescences 1-3(-5)-flowered; seeds brown or reddish brown, 0.4-0.6 mm | M. stricta |
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