Salix hookeriana
Salix subg. Vetrix
coastal willow, dune willow, Hooker's willow
branches (highly brittle at base), yellow-brown, gray-brown, red-brown, or violet, not or weakly glaucous, glabrous, tomentose, woolly, or sparsely villous to glabrescent (nodes hairy);
branchlets gray-brown, red-brown, or yellow-brown (sometimes color obscured by hairs), glabrous, pilose, moderately densely villous, tomentose, or woolly, scale with inner membranaceous layer free, (not separating from outer layer).
usually erect or decumbent;
branches usually flexible at base, usually not glaucous, (dull to highly glossy).
usually alba-type, sometimes caprea-type or intermediate, scale margins connate, (inner membranaceous layer sometimes free and separating from outer layer).
stipules rudimentary or absent on early ones, foliaceous (early deciduous) or rudimentary (sometimes obscured) on late ones, (2.5–7.8–18 mm), apex acuminate, acute, or rounded;
petiole convex to flat, or shallowly grooved adaxially, 4–29 mm, villous, woolly, pilose, or tomentose adaxially;
largest medial blade (sometimes hemiamphistomatous), narrowly to broadly elliptic, oblanceolate, or obovate to broadly obovate, 36–123 × 18–63 mm, 1.5–4.2 times as long as wide, base convex, rounded, subcordate, cordate, or cuneate, margins slightly revolute, crenate, serrate, shallowly serrulate, sinuate, or entire, apex acuminate, acute, or convex, abaxial surface glaucous, pilose, moderately densely tomentose, villous, or woolly, midrib hairy, hairs (white, sometimes also ferruginous), wavy or straight, adaxial highly or slightly glossy, glabrous, pilose, villous, or moderately densely tomentose, midrib and veins hairy (hairs white, sometimes also ferruginous);
proximal blade margins entire or shallowly serrulate;
juvenile blade yellowish, reddish green (sometimes obscured by hairs), pilose or sparsely to densely long-silky, tomentose, woolly, or villous abaxially, hairs white, sometimes also ferruginous, or yellowish.
stipules on early ones absent, rudimentary, or foliaceous, on late ones usually foliaceous, sometimes rudimentary or absent;
petioles usually convex to flat, or shallowly grooved adaxially, sometimes deeply grooved, usually not glandular distally;
largest medial blade usually hypostomatous, sometimes amphistomatous or hemiamphistomatous, (glands, if present, usually marginal or submarginal), linear, lorate, narrowly oblong, oblong, narrowly to broadly elliptic, oblanceolate, obovate, or broadly obovate, 0.7–13.7 times as long as wide, angle of base and of apex less or greater than 90o, surface (usually not glaucous abaxially), hairs usually white, sometimes also ferruginous or gray;
juvenile blade hairs white, sometimes also ferruginous.
adaxial nectary oblong, ovate, or narrowly oblong, 0.5–1.4 mm;
filaments distinct or slightly basally connate, glabrous or hairy on proximal 1/2 or basally;
anthers yellow, cylindrical or ellipsoid, (0.5–)0.7–1 mm.
abaxial nectary usually absent (except S. wolfii, rarely S. argyrocarpa and S. breweri);
stamens 2, (1 in sect. Sitchenses);
filaments distinct or connate, glabrous or hairy;
anthers usually purple or red turning yellow.
adaxial nectary narrowly oblong, oblong, or square, 0.5–1.4 mm, shorter than stipe;
stipe 0.5–1.8(–2.8) mm;
ovary obclavate or pyriform, glabrous, tomentose, villous, or woolly (hairs wavy), beak sometimes abruptly tapering to styles;
ovules 12–20 per ovary;
styles 0.6–2.3 mm;
stigmas broadly to slenderly cylindrical, 0.3–0.8 mm.
abaxial nectary usually absent;
ovary not glaucous, glabrous or hairy, hairs usually flattened, beak usually gradually tapering to or slightly bulged below styles;
ovules 2–37 per ovary;
styles usually connate, sometimes distinct;
stigmas flat, abaxially non-papillate with rounded or pointed tip, or stigmas slenderly or broadly cylindrical, or 2 plump lobes.
5–10 mm.
flowering before or as leaves emerge; staminate slender or stout, 26–73 × 10–27 mm, flowering branchlet 0–10 mm; pistillate densely flowered, slender or stout, 36–92(–140 in fruit) × 10–25 mm, flowering branchlet 0–20 mm;
floral bract brown, black, or bicolor, 1.1–3.6 mm, apex convex, rounded, or acute, abaxially hairy, hairs straight or wavy.
flowering as or just before leaves emerge, from lateral buds; staminate on flowering branchlet or sessile, usually stout, or slender to globose; pistillate on flowering branchlet or sessile, usually densely flowered, sometimes loosely, usually stout or subglobose to globose, sometimes slender;
floral bract usually brown, black, tawny, bicolor, or sometimes light rose, apex usually entire; pistillate bract usually persistent after flowering.
= 114.
= 38 (29), 57 (1), 76 (16), 95 (1), 114 (4), unknown (21).
Salix hookeriana
Salix subg. Vetrix
Salix hookeriana is primarily a coastal species occurring from northern California northward to Oregon, Washington, and southern Vancouver Island, with disjunct populations on Queen Charlotte Islands, British Columbia, and northward to Yakatut Bay, Turnagain Arm, and Kodiak, Alaska. It was treated by G. W. Argus (1973) and R. D. Dorn (2000) in a broad sense because of an absence of strong distinguishing characters and intergradation in characters that could be used to divide it. It is highly variable and three very similar taxa have been named: S. amplifolia, S. hookeriana (including vars. tomentosa and laurifolia), and S. piperi. Although extremes of these taxa sometimes are recognizable, the intergradation displayed is so great that even attempts to recognize them as varieties are thwarted. The amplifolia variant in Alaska is characterized by having only white leaf hairs, hairy ovaries, no stipules, and catkins often borne on distinct flowering branchlets, but variation can occur within the same population, and typical S. hookeriana on Vancouver Island sometimes displays the same characteristics. The piperi variant, an inland population in western Oregon and Washington, is usually recognized by local botanists as different from coastal populations. It is characterized by leaves and branchlets soon becoming glabrate and stipules prominent. These characteristics, however, sometimes appear in northern California coastal populations, and some inland populations in Oregon include very hairy individuals that are indistinguishable from coastal variants of S. hookeriana. In general, very hairy populations of S. hookeriana are probably an adaptation to marine coastal environments, but some variation may be due to hybridization and introgression with S. scouleriana. Inland populations suggest the influence of S. lasiolepis. Two hexaploid chromosome numbers reported for S. hookeriana from Vancouver Island (R. L. Taylor and S. Taylor 1977) and Queen Charlotte Islands (R. L. Taylor and G. A. Mulligan 1968), British Columbia, indicate that hybridization has played a role in the evolution of this complex. It is possible that each variant of S. hookeriana has had a different, possibly even recurrent, polyploid origin. Further cytological and genetic study is indicated.
The following comparisons may help to distinguish Salix hookeriana, S. lasiolepis, and S. scouleriana.
Vegetative specimens of Salix hookeriana can be distinguished from S. lasiolepis by having floral buds ellipsoid, beaks distinctly long-tapered, densely long-hairy (villous), red-brown, blades usually pilose, villous, or woolly on abaxial surfaces, usually 18–63 mm wide, and 1.5–4.2 times as long as wide; S. lasiolepis has floral buds ovoid, beaks inconspicuous and blunt, sparsely to moderately densely short-hairy (velvety), yellowish to red-brown, blades usually tomentose on abaxial surfaces, usually 6–32 mm wide, and 3.2–9.6 times as long as wide.
Salix hookeriana is distinguished from S. scouleriana by having branchlets with spreading hairs (woolly or tomentose to glabrate), petioles usually pilose to tomentose, blades typically narrowly elliptic but variable, stigmas 0.3–0.74, short in relation to styles (0.6–2.3 mm), and pistillate nectaries 0.5–1.4 mm, shorter or longer than stipes; S. scouleriana has branchlets usually with short, erect hairs (velutinous), sometimes spreading (villous or tomentose), petioles velvety or villous adaxially, blades typically oblanceolate but variable, stigmas 0.4–1.04 mm, long in relation to styles (0.2–0.6 mm), and pistillate nectaries 0.2–0.8 mm, shorter than stipes.
Hybrids:
Salix hookeriana forms natural hybrids with S. barclayi and S. scouleriana. Variation in some S. hookeriana populations suggests hybridization with S. lasiolepis but no positive identifications have been made. R. D. Dorn (2000) doubted that hybridization in California between these species with different chromosome numbers was possible, but species with different chromosome numbers do hybridize [for example, S. athabascensis (4x) × S. pedicellaris (2x)]; synthetic hybridization studies are indicated.
Salix hookeriana × S. scouleriana: Plants from southern British Columbia with leaves similar to S. hookeriana but with prominent stipules, catkins both erect and recurving, and relatively long stigmas were thought by J. K. Henry (1915) to be this hybrid.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species ca. 204 (63 species in the flora).
Nineteen of the 29 sections recognized in this subgenus are found in the flora area.
Although it may be difficult to be certain if a plant is native or introduced, certain assumptions can be made. If it is growing in a wilderness area (alpine, arctic, boreal, desert) or far from human habitation, the probability that it is an introduction is very small; but if it is growing in a settled area, particularly on anthropogenically disturbed sites, or growing in rows suggesting planting along fencerows or as a windbreak, then it could be suspected to be an introduction. The possibility that it is a natural hybrid between native species cannot be excluded and both leads may need to be followed.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants presumed introduced and widely naturalized in the flora area | → 2 |
1. Plants presumed native in the flora area | → 12 |
2. Stipules on late leaves absent or rudimentary | → 3 |
2. Stipules on late leaves foliaceous | → 4 |
3. Leaves and catkins alternate; branchlets densely pubescent or tomentose; largest medial blades: abaxial surface densely tomentose or woolly; floral bracts tawny or brown; ovaries glabrous; stipes 0.3-0.5 mm. | S. elaeagnos |
3. Leaves and catkins often opposite or subopposite; branchlets glabrous; largest medial blades: abaxial surface glabrous; floral bracts bicolor or black; ovaries short-silky; stipes 0-0.1 mm. | S. purpurea |
4. Petioles shallowly grooved adaxially | → 5 |
4. Petioles flat to convex adaxially | → 7 |
5. Branches yellow-brown, gray-brown, or yellowish; largest medial blades: abaxial surface apparently glaucous but obscured by hairs, margins strongly revolute, glands epilaminal; stigmas 0.72-1.8 mm. | S. viminalis |
5. Branches red-brown or gray-brown; largest medial blades: abaxial surface distinctly glaucous or not, margins sometimes slightly revolute or flat, glands submarginal or marginal; stigmas 0.3-0.68 mm | → 6 |
6. Branches not glaucous; stipules reniform, not adnate to petiole; largest medial blades broader, 1.1-2.8 times as long as wide, elliptic, broadly elliptic, subcircular or broadly obovate, apex abruptly acuminate or acute, abaxial surface often not glaucous apically. | S. myrsinifolia |
6. Branches strongly glaucous; stipules lanceolate to ovate, often adnate to petiole; largest medial blades 2.5-6.4 times as long as wide, lorate, oblong, narrowly elliptic or elliptic, apex gradually acuminate, abaxial surface uniformly and distinctly glaucous. | S. daphnoides |
7. Largest medial blades with veins strongly impressed adaxially; branchlets sometimes weakly glaucous, tomentose. | S. aurita |
7. Largest medial blades flat or with veins slightly impressed adaxially; branchlets not glaucous, puberulent, pubescent, pilose, villous, or velvety | → 8 |
8. Petioles puberulent or villous adaxially; branches red-brown, glabrous; catkins flowering as leaves emerge; ovaries glabrous or sparsely hairy. | S. myrsinifolia |
8. Petioles glabrescent, pubescent, tomentose, or velvety adaxially; branches yellowish, yellow-brown, or gray-brown, pubescent, pilose, villous, or tomentose to glabrescent; catkins flowering before leaves emerge; ovaries short- or long-silky | → 9 |
9. Peeled wood smooth or with striae to 6 mm; ovaries: beak gradually tapering to styles | → 10 |
9. Peeled wood with striae to 62 mm; ovaries: beak slightly bulged below styles | → 11 |
10. Largest medial blades usually 2-3 times as long as wide; branches flexible at base; stipes 2-2.5 mm; styles 0.3-0.6 mm; stigma lobes 0.4-0.6 mm. | S. caprea |
10. Largest medial blades usually 2.8-6.4 times as long as wide; branches ± brittle at base; stipes 0.9-2 mm; styles 0.5-1.2 mm; stigma lobes 0.6-1.2 mm [2e4. Salix sect. Cinerella] | S. ×smithiana |
11. Shrubs, 3-7(-10) m; largest medial blades: abaxial surface with white hairs; branches brownish, to 62 mm. | S. cinerea |
11. Shrubs or small trees, 3-12 m; largest medial blades: abaxial surface with white and ferruginous hairs; branches yellow-brown, gray-brown, or red-brown, to 45 mm. | S. atrocinerea |
12. Flowering before leaves emerge (sometimes just before in S. irrorata, S. myricoides, and S. tracyi); catkins usually sessile or on very short flowering branchlets (staminate 0-5 mm, to 9 mm in S. myricoides, pistillate 0-14 mm, to 35 mm in S. hookeriana) | → 13 |
12. Flowering as leaves emerge (staminate catkins sometimes emerge just before in S. irrorata, S. myricoides, and S. tracyi), catkins usually on distinct flowering branchlets (staminate 0-30 mm, pistillate 0.5-38 mm) | → 54 |
13. Ovaries glabrous | → 14 |
13. Ovaries hairy | → 28 |
14. Stipules usually marcescent | S. sect. Lanatae |
14. Stipules deciduous (in autumn) | → 17 |
15. Largest medial blades: apex acuminate, acute, or rounded; stipules 1-6-14 mm, 1.1-1.8-4.4 times as long as wide, usually ovate to oval or narrowly elliptic, pressing flat. | S. calcicola |
15. Largest medial blades: apex acute, acuminate, or convex; stipules 3-35 mm, 1.1-6 times as long as wide, shape variable, pressing with a pleat | → 16 |
16. Largest medial blades slightly glossy adaxially; floral bracts moderately densely hairy; pistillate adaxial nectaries 2+-lobed; stipules 3-12-35 mm, 1.7-3.6-6 times as long as wide, lanceolate or narrowly elliptic, sometimes ovate or oval. | S. richardsonii |
16. Largest medial blades dull adaxially; floral bracts sparsely hairy; pistillate adaxial nectaries unlobed; stipules 3.5-10-23 mm, 1-1.4- 2.8 times as long as wide, lanceolate, ovate, or suborbiculate. | S. tweedyi |
17. Largest medial blades dull adaxially | → 18 |
17. Largest medial blades slightly to highly glossy adaxially | → 20 |
18. Ovaries: beak slightly bulged below styles; styles 0.3-0.6 mm; floral bracts moderately to very densely hairy; east of 102d meridian. | S. eriocephala |
18. Ovaries: beak gradually tapering to styles; styles 0.5-1.8 mm; floral bracts sparsely hairy; usually west of 102d meridian | → 19 |
19. Petioles usually reddish; catkins usually sessile, flowering branchlets sometimes to 5 mm; juvenile blades glabrous or pubescent; stigmas 0.1-0.29 mm; stipes 0.5-3 mm; Canada to Montana, Black Hills of South Dakota, n Wyoming. | S. pseudomonticola |
19. Petioles green; catkins on distinct flowering branchlets 0.5-7 mm; juvenile blades villous or long-silky; stigmas 0.24-0.56 mm; stipes 0.5-1.6 mm; ne Arizona, Colorado, nw New Mexico, Utah, s Wyoming. | S. monticola |
20. Largest medial blades: margins often entire, sometimes irregularly serrate or crenate | → 21 |
20. Largest medial blades: margins regularly toothed | → 24 |
21. Largest medial blades usually 1.5-5.2 times as long as wide, bases often rounded to cordate; pistillate flowering branchlets 0-20 mm; styles distinct to 1/2 their lengths or connate, 0.3-2.3 mm; capsules 5-10 mm | → 22 |
21. Largest medial blades usually 1.9-9.6 times as long as wide, bases usually cuneate or convex; pistillate flowering branchlets 0-6 mm; styles connate, 0.1-0.9 mm; capsules 2.5-5.5 mm | S. sect. Mexicanae |
22. Pistillate catkins loosely flowered; pistillate flowering branchlets 1.5-13 mm; filaments glabrous; styles 0.3-1.3 mm; e North America. | S. myricoides |
22. Pistillate catkins densely flowered; pistillate flowering branchlets 0-20 mm; filaments hairy or glabrous; styles 0.6- 2.3 mm; w North America. | S. hookeriana |
23. Branches strongly glaucous; juvenile blades glabrous or sparsely villous; largest medial blades glabrous or pilose adaxially, hairs white. | S. irrorata |
23. Branches usually not glaucous, sometimes weakly so; juvenile blades sparsely to very densely tomentose, woolly or silky; largest medial blades glabrescent, tomentose, or short-silky adaxially, hairs usually white, sometimes also ferruginous. | S. lasiolepis |
24. Glands on largest medial blades submarginal | → 25 |
24. Glands on largest medial blades marginal | → 26 |
25. Pistillate catkins loosely flowered; pistillate flowering branchlets 1.5-13 mm; filaments glabrous; styles 0.3-1.3 mm; e North America. | S. myricoides |
25. Pistillate catkins densely flowered; pistillate flowering branchlets 0-20 mm; filaments hairy or glabrous; styles 0.6-2.3 mm; w North America. | S. hookeriana |
26. Petioles short-silky or velvety adaxially; staminate catkins not on flowering branchlets; floral bracts with straight hairs; ovules 18 per ovary. | S. pseudomonticola |
26. Petioles villous, tomentose, pilose, or pubescent adaxially; staminate catkins on flowering branchlets; floral bracts usually with wavy or curly hairs; ovules 12-16 per ovary | → 27 |
27. Largest medial blades with relatively very thick glaucescence abaxially, usually 2-5.2 times as long as wide; floral bracts brown to black; styles 0.3-1.3 mm; pistillate flowering branchlets 1.5-13 mm. | S. myricoides |
27. Largest medial blades with relatively thin glaucescence abaxially, usually 2.3-8 times as long as wide; floral bracts tawny or light brown; styles 0.3-0.6 mm; pistillate flowering branchlets 2-10 mm. | S. eriocephala |
28. Stipules on early leaves absent or rudimentary | → 29 |
28. Stipules on early leaves foliaceous (rarely so in S. drummondiana and S. pellita) | → 41 |
29. Ovaries obturbinate or squat, flask-shaped (serpentine endemics, California, Oregon) | S. sect. Sitchenses |
29. Ovaries pyriform or obclavate (not serpentine endemics) | → 31 |
30. Floral bracts usually tawny, densely hairy; largest medial blades lorate, very narrowly elliptic or oblanceolate, apex acuminate or acute; ovaries squat, flask-shaped, beak abruptly tapering to styles; branches flexible at base. | S. breweri |
30. Floral bracts brown, sparsely to moderately densely hairy; largest medial blades elliptic or obovate, apex convex or rounded; ovaries obturbinate, beak gradually tapering to styles; branches highly brittle at base. | S. delnortensis |
31. Largest medial blades highly glossy adaxially | → 32 |
31. Largest medial blades dull or slightly glossy adaxially | → 35 |
32. Ovaries villous, tomentose, or woolly; stipes 0.5-2.2 mm; anthers yellow (Alaska to n California). | S. hookeriana |
32. Ovaries silky; stipes 0.2-1.1 mm; anthers purple turning yellow in age | S. sect. Phylicifoliae |
33. Largest medial blades usually 4.2-11.3 times as long as wide, linear, lorate or narrowly elliptic, abaxial surface usually very densely villous, short-silky, tomentose, or woolly (sometimes sparsely so), glands marginal or epilaminal; petioles sometimes with 2 spherical glands distally; branches brittle at base. | S. pellita |
33. Largest medial blades usually 1.5-5.1 times as long as wide, obovate, oblanceolate, narrowly oblong, elliptic, or narrowly elliptic, abaxial surface glabrous or sparsely silky, glands marginal or submarginal; petioles without glands at base of blade; branches flexible at base | → 34 |
34. Largest medial blades usually hypostomatous (sometimes hemiamphistomatous). | S. planifolia |
34. Largest medial blades amphistomatous. | S. tyrrellii |
35. Stems decumbent, 0.3-3 m, layering, not glaucous or weakly so; largest medial blades: hairs white or gray; styles 0.2-0.4 mm; stigmas 0.2-0.56 mm. | S. humilis |
35. Stems erect, 0.5-6 m, not layering, often strongly glaucous; largest medial blades: hairs white, sometimes also ferruginous; styles 0.3-1.5 mm; stigmas 0.32-0.76 mm | → 36 |
36. Largest medial blades: abaxial surface often obscured by dense hairs | S. sect. Phylicifoliae |
36. Largest medial blades: abaxial surface not obscured by hairs | → 38 |
37. Petioles villous or velvety adaxially; largest medial blades usually 3-6.2 times as long as wide, glands submarginal; w North America. | S. drummondiana |
37. Petioles glabrous or pubescent adaxially; largest medial blades usually 4.2-11.3 times as long as wide, glands submarginal or epilaminal; e North America. | S. pellita |
38. Largest medial blades 4.2-11.3 times as long as wide, linear to narrowly elliptic; capsules 3.5-6.5 mm. | S. pellita |
38. Largest medial blades 1.5-4.5 times as long as wide, narrowly elliptic to obovate or broadly so; capsules 4.5-11 mm | S. sect. Cinerella |
39. Petioles and branchlets velvety; styles 0.2-0.6 mm; largest medial blades usually oblanceolate; ovaries densely long-silky. | S. scouleriana |
39. Petioles and branchlets not velvety; styles 0.3-2.3 mm; largest medial blades elliptic, oblanceolate, or obovate; ovaries moderately densely short-silky or densely villous, tomentose, or woolly | → 40 |
40. Stipes 1.6-2.7 mm; ovaries short-silky, hairs straight; styles 0.3-1 mm; pistillate flowering branchlets 0-10 mm; largest medial blades dull or slightly glossy adaxially, margins flat; primarily e North America to c British Columbia. | S. discolor |
40. Stipes 0.5-2.2 mm; ovaries villous, tomentose, or woolly, hairs wavy; styles 0.6-2.3 mm; pistillate flowering branchlets 0-20 mm; largest medial blades slightly to highly glossy adaxially, margins slightly revolute; Alaska to n California. | S. hookeriana |
41. Pistillate nectaries usually shorter than or equal to stipes | → 42 |
41. Pistillate nectaries as long as or longer than stipes | → 47 |
42. Largest medial blades amphistomatous. | S. tyrrellii |
42. Largest medial blades usually hypostomatous (or hemiamphistomatous) | → 43 |
43. Stipes 0.3-0.8 mm. | S. planifolia |
43. Stipes 0.8-2.7 mm | S. sect. Cinerella |
44. Largest medial blades with revolute margins | → 45 |
44. Largest medial blades with flat margins | → 46 |
45. Shrubs, 0.3-3 m, forming clones by layering; juvenile blades tomentose to glabrescent; anthers 0.4-0.6 mm; ovaries sparsely to moderately densely short-silky. | S. humilis |
45. Shrubs or trees, 3-10(-20) m, not clonal; juvenile blades villous or silky; anthers 0.7-1.2 mm; ovaries very densely long-silky. | S. scouleriana |
46. Ovaries short-silky, hairs straight; stipes 1.6-2.7 mm; primarily e North America to c British Columbia. | S. discolor |
46. Ovaries villous, tomentose, or woolly, hairs wavy; stipes 0.5-2.2 mm; Alaska to n California. | S. hookeriana |
47. Floral bracts tawny or light rose; styles 0.4-0.8 mm; stigmas 0.16-0.24 mm; ovaries squat, flask-shaped. | S. breweri |
47. Floral bracts brown or black; styles 0.5-2.3 mm; stigmas 0.2-1.28 mm; ovaries obturbinate, obclavate, or pyriform | → 48 |
48. Ovaries long- or short-silky, hairs straight | → 49 |
48. Ovaries tomentose, villous, or woolly, hairs wavy | → 51 |
49. Largest medial blades 29-54 mm wide; branchlets and petioles velvety; branches highly brittle at base. | S. delnortensis |
49. Largest medial blades 5-28 mm wide; branchlets and petioles glabrous, pilose, puberulent, villous, or short-silky; branches flexible at base | S. sect. Phylicifoliae |
50. Stipules usually marcescent, foliaceous, linear or lanceolate, 2-9.8-23 mm; juvenile blades glabrous or pilose; largest medial blades narrowly elliptic, elliptic, or obovate. | S. pulchra |
50. Stipules sometimes marcescent, rudimentary or foliaceous, ovate, oblong, or narrowly elliptic, 1-2.5(-4.5) mm; juvenile blades glabrous, puberulent, pubescent, or densely long-silky; largest medial blades narrowly oblong, narrowly elliptic, elliptic, or oblanceolate. | S. planifolia |
51. Largest medial blades: abaxial surface glaucous or sparsely to moderately densely hairy, hairs white, sometimes also ferruginous, slightly or highly glossy adaxially; stipes 0.5-2.2 mm; branches highly brittle at base. | S. hookeriana |
51. Largest medial blades: abaxial surface very densely hairy, hairs white, dull or slightly glossy adaxially; stipes 0-0.6 mm; branches flexible at base | → 52 |
52. Stipules resinous; floral bracts 2.8-5.2 mm; largest medial blades slightly glossy adaxially, margins flat; petioles weakly ventricose around floral buds. | S. barrattiana |
52. Stipules not resinous; floral bracts 1.5-3 mm; largest medial blades dull adaxially, margins revolute; petioles strongly ventricose around floral buds | → 53 |
53. Largest medial blades: abaxial surface villous to tomentose, adaxially sparsely to moderately densely hairy; floral bracts: apex often acute to convex, sometimes crenate; stipules sometimes marcescent. | S. alaxensis |
53. Largest medial blades: abaxial surface tomentose to woolly, adaxially moderately to very densely hairy; floral bracts: apex convex to rounded, entire; stipules deciduous (in autumn). | S. silicicola |
54. Ovaries hairy. | → 55 |
54. Ovaries glabrous | S. sects. 2e1. Hastatae and 2e2. Cordatae |
55. Plants east of 102d meridian (longitudal line passing through the ne corner of Saskatchewan, along e border of Colorado) | → 56 |
55. Plants west of 102d meridian (longitudal line passing through the ne corner of Saskatchewan, along e border of Colorado) | → 62 |
56. Stipules on late leaves usually foliaceous | → 57 |
56. Stipules on late leaves usually absent or rudimentary | → 59 |
57. Branchlets, petioles adaxially, abaxial surface of largest medial blade densely woolly or tomentose; ovaries tomentose or woolly. | S. candida |
57. Branchlets, petioles adaxially, abaxial surface of largest medial blade glabrous, puberulent, villous, or long-silky; ovaries short-silky | → 58 |
58. Largest medial blades: margins flat, entire, crenate, or irregularly serrate, adaxial surface dull or slightly glossy; ovaries obclavate; floral bracts 1.2-3.2 mm; stipes 2-6 mm. | S. bebbiana |
58. Largest medial blades: margins slightly revolute, serrulate, adaxial surface slightly or highly glossy; ovaries pyriform; floral bracts 0.8-1.2 mm; stipes 0.6-0.9 mm. | S. arbusculoides |
59. Largest medial blades: abaxial surface short-silky, hairs usually white (rarely ferruginous); branches highly brittle at base; floral bracts brown to black; ovaries ovoid; styles 0.2-0.4 mm; stipes 0.6-1.5 mm. | S. sericea |
59. Largest medial blades: abaxial surface long-silky, villous, pilose, or pubescent to glabrescent, hairs white, often with some ferruginous; branches flexible at base; floral bracts tawny to brown; ovaries pyriform or obclavate; styles 0-0.9 mm; stipes 1-6 mm | → 60 |
60. Shrubs delicate, 0.2-1 m; largest medial blades with strongly revolute margins; pistillate catkins densely flowered; capsules 2-4 mm; styles 0.4-0.9 mm; floral bracts 0.7-1.2 mm. | S. argyrocarpa |
60. Shrubs coarse, 0.5-10 m; largest medial blades with flat or slightly revolute margins; pistillate catkins loosely flowered; capsules 5-9 mm; styles 0-0.5 mm; floral bracts 1-3.2 mm | → 61 |
61. Largest medial blades 1.7-3.9 times as long as wide, narrowly oblong to obovate, hairs white or gray, margins crenate or entire, adaxial surface finely impressed-reticulate; floral bracts tawny; ovaries obclavate. | S. bebbiana |
61. Largest medial blades 5-9 times as long as wide, lorate to very narrowly elliptic, hairs white, sometimes also ferruginous, margins serrulate, serrate, or entire, adaxial surface not finely impressed-reticulate; floral bracts brown, tawny, light rose or bicolor; ovaries pyriform. | S. petiolaris |
62. Petioles glabrescent or puberulent adaxially | → 63 |
62. Petioles pubescent, pilose, villous, tomentose, woolly, short-silky, long-silky, or velvety adaxially | → 65 |
63. Branchlets glabrous or puberulent; juvenile blades very densely long-silky; stipes 0.6-0.9 mm; pistillate adaxial nectaries equal to or as long as stipes; ovaries very densely short-silky, beaks gradually tapering to styles. | S. arbusculoides |
63. Branchlets pubescent, villous, or velvety; juvenile blades pilose, tomentose, or sparsely or moderately densely long-silky; stipes 1.5-6 mm; pistillate adaxial nectaries shorter than stipes; ovaries densely to sparsely hairy, beaks abruptly tapering to or slightly bulged below styles | → 64 |
64. Largest medial blades narrowly oblong, narrowly elliptic, elliptic, oblanceolate, or obovate, 1.7-3.9 times as long as wide, hairs on abaxial surface divergent, wavy; branchlets villous to glabrescent; ovaries obclavate, beaks slightly bulged below styles. | S. bebbiana |
64. Largest medial blades lorate or very narrowly elliptic, 5-9 times as long as wide, hairs on abaxial surface appressed, straight; branchlets pubescent or velvety; ovaries pyriform, beak abruptly tapering to styles. | S. petiolaris |
65. Largest medial blades not glaucous abaxially | → 66 |
65. Largest medial blades glaucous abaxially or surfaces obscured by hairs | → 67 |
66. Branchlets yellow-green or red-brown, pilose or villous; anthers 0.5-0.9 mm; floral bracts 1.4-2.8 mm; pistillate catkins 11-51 mm. | S. eastwoodiae |
66. Branchlets yellowish or yellow-brown, pubescent or long-silky; anthers 0.3-0.5 mm; floral bracts 0.8-2 mm; pistillate catkins 8.5-19 mm. | S. wolfii |
67. Largest medial blades: abaxial surface densely tomentose or woolly, with crinkled and interwoven hairs, adaxial surface often floccose, hairs white. | S. candida |
67. Largest medial blades: abaxial surface without crinkled, interwoven hairs, adaxial surface not floccose, hairs white or, sometimes, also ferruginous | → 68 |
68. Largest medial blades: abaxial surface very densely hairy; peeled wood on branches inconspicuous (sometimes conspicuous in S. geyeriana) | → 69 |
68. Largest medial blades: abaxial surface sparsely or moderately densely hairy; peeled wood on branches conspicuous | → 71 |
69. Largest medial blades 3.6-11.3 times as long as wide, linear, or lorate to very narrowly elliptic; pistillate catkins globose or subglobose; anthers 0.4-0.5 mm; stamens 2. | S. geyeriana |
69. Largest medial blades 2.1-7.7 times as long as wide, lorate, elliptic, narrowly oblanceolate, oblanceolate, or obovate; pistillate catkins slender to stout; anthers 0.5-0.8 mm; stamens 1 or 2 | S. sect. Sitchenses |
70. Largest medial blades 2.1-3.1-4 times as long as wide, margins strongly or slightly revolute, entire or toothed, glands submarginal or epilaminal, abaxial surface woolly, short-silky, or silky-woolly; staminate catkins 22-54 mm, slender or stout; stamens 1; filaments glabrous; pistillate adaxial nectaries square, ovate, or flask-shaped. | S. sitchensis |
70. Largest medial blades (2.5-)3.3-5.3-7.3 times as long as wide, margins slightly revolute or flat, entire, glands submarginal, abaxial surface short-silky; staminate catkins 16-16.5 mm, stout or subglobose; stamens 1 or 2; filaments hairy on proximal 1/2; pistillate adaxial nectaries narrowly oblong, oblong, or flask-shaped. | S. jepsonii |
71. Largest medial blades: margins entire, abaxial surface sparsely to moderately densely short- or long-silky, adaxial surface usually dull; filaments hairy basally; anthers purple turning yellow. | S. orestera |
71. Largest medial blades: margins crenate, serrate, serrulate, or entire, abaxial surface glabrous, pilose, tomentose, villous, woolly, or short- or long-silky, adaxial surface slightly or highly glossy; filaments glabrous or hairy; anthers yellow or purple turning yellow | → 72 |
72. Largest medial blades 1.5-4.2 times as long as wide, 18-63 mm wide, margins entire, irregularly serrate, crenate, or sinuate, adaxial surface pilose, villous, or tomentose; staminate catkins 26-73 mm; pistillate catkins 36-117 mm; styles 0.6-2.3 mm. | S. hookeriana |
72. Largest medial blades 3.4-12 times as long as wide, 5.4-22 mm wide, margins entire or serrulate, adaxial surface silky to glabrescent; staminate catkins 11-28 mm; pistillate catkins 8-44 mm; styles 0.1-1 mm | → 73 |
73. Catkins globose to subglobose; floral bracts usually tawny, sometimes brown; anthers 0.4-0.5 mm, yellow or purple turning yellow; styles 0.1-0.6 mm; stipules absent or rudimentary; proximal blades with entire margins. | S. geyeriana |
73. Catkins stout; floral bracts dark brown or bicolor; anthers 0.5-0.9 mm, yellow; styles 0.3-1 mm; stipules foliaceous; proximal blades with entire or serrulate margins. | S. lemmonii |
74. Plants east of 102d meridian (longitudal line passing through the ne corner of Saskatchewan, along e border of Colorado) | → 75 |
74. Plants west of 102d meridian (longitudal line passing through the ne corner of Saskatchewan, along e border of Colorado) | → 81 |
75. Largest medial blades not glaucous abaxially | → 76 |
75. Largest medial blades glaucous abaxially | → 78 |
76. Juvenile blades densely villous on abaxial surface or midrib long-silky; largest medial blades usually villous on abaxial surface, hairs white; petioles tomentose adaxially; pistillate adaxial nectaries 0.4-1.3 mm; floral bracts 1-2.6 mm. | S. cordata |
76. Juvenile blades glabrous on abaxial surface or midrib sparsely pubescent to short-silky; largest medial blades glabrous or pilose on abaxial surface, hairs white and, sometimes, ferruginous; petioles glabrous, pubescent, or villous adaxially; pistillate adaxial nectaries 0.2-0.4 mm; floral bracts 0.4-1.1 mm | → 77 |
77. Shrubs decumbent, 0.1-0.6(-1) m; stipules on late leaves rudimentary to foliaceous, 0.2-1.8(-5) mm; styles 0.3-0.7 mm; proximal blades with crenate margins. | S. myrtillifolia |
77. Shrubs erect, 1-7 m; stipules on late leaves foliaceous, 0.5-6 mm; styles 0.4-1.6 mm; proximal blades with entire or serrulate margins. | S. pseudomyrsinites |
78. Floral bracts tawny; ovaries obclavate. | S. pyrifolia |
78. Floral bracts usually brown or black; ovaries pyriform | → 79 |
79. Largest medial blades 1.4-2.8 times as long as wide, elliptic to obovate, apex usually convex or rounded, sometimes acute; stipules on early leaves absent or rudimentary, on late leaves foliaceous; proximal blades with serrulate or crenulate margins. | S. ballii |
79. Largest medial blades 2-8 times as long as wide, usually narrowly oblong, very narrowly elliptic or oblanceolate (sometimes elliptic or obovate), apex acuminate or acute; stipules on all leaves foliaceous; proximal blades with entire or serrulate margins | → 80 |
80. Largest medial blades very thickly glaucous abaxially, surface hairs often ferruginous; stigmas 0.24-0.56 mm; pistillate catkins loosely flowered. | S. myricoides |
80. Largest medial blades thinly or moderately glaucous abaxially, surface hairs usually white; stigmas 0.2-0.3 mm; pistillate catkins densely or moderately densely flowered. | S. eriocephala |
81. Largest medial blades not glaucous abaxially | S. sects. 2e1. Hastatae and 2e2. Cordatae |
81. Largest medial blades glaucous abaxially | → 91 |
82. Largest medial blades to 60 mm, margins entire, not glandular-dotted; pistillate catkins 8.5-19 mm; stipules deciduous (in autumn); staminate flowers often with abaxial and adaxial nectaries. | S. wolfii |
82. Largest medial blades to 102 mm, margins usually toothed, if entire then also glandular-dotted; pistillate catkins 11-73 mm; stipules often marcescent; staminate flowers without abaxial nectary | → 83 |
83. Largest medial blades: surfaces dull adaxially | → 84 |
83. Largest medial blades: surfaces slightly glossy adaxially | → 87 |
84. Branchlets pilose, villous, or woolly | → 85 |
84. Branchlets glabrous or puberulent | → 86 |
85. Juvenile blades tomentose, woolly, or long-silky; largest medial blades 1.5-3.4 times as long as wide, hairs white; pistillate flowering branchlets 3-15 mm; floral bracts: apex rounded to acute. | S. commutata |
85. Juvenile blades villous to pilose; largest medial blades 2-5.2 times as long as wide, hairs usually white and ferruginous; pistillate flowering branchlets 1-9 mm; floral bracts: apex rounded to retuse. | S. boothii |
86. Juvenile blades pilose to villous abaxially; stigmas slenderly cylindrical, flat, abaxially non-papillate with rounded tip, or 2 plump lobes; styles 0.3-1.4 mm; largest medial blades often amphistomatous. | S. boothii |
86. Juvenile blades glabrous or short- to long-silky abaxially; stigmas broadly cylindrical or flat, non-papillate abaxially, tip rounded; styles 0.2-0.5 mm; largest medial blades hypostomatous. | S. monochroma |
87. Floral bracts 0.4-1.1 mm; pistillate nectaries 0.2-0.4 mm; stipules on early leaves absent, rudimentary, or foliaceous; petioles deeply to shallowly grooved adaxially, usually glabrous | → 88 |
87. Floral bracts 0.7-3 mm; pistillate nectaries 0.3-1 mm; stipules foliaceous; petioles flat to shallowly grooved adaxially, pilose, tomentose, villous, or pubescent to glabrescent | → 89 |
88. Shrubs decumbent, 0.1-0.6(-1) m; stipules on late leaves rudimentary to foliaceous, 0.2-1.8(-5) mm; styles 0.3-0.7 mm; proximal blades with crenate margins. | S. myrtillifolia |
88. Shrubs erect, 1-7 m; stipules on late leaves foliaceous, 0.6-8 mm; styles 0.4-1.6 mm; proximal blades with entire or serrulate margins. | S. pseudomyrsinites |
89. Juvenile blades tomentose or long-silky; largest medial blades: abaxial surface usually moderately densely tomentose or villous (sometimes pilose to glabrescent), adaxial surface pilose or moderately densely villous to glabrescent; floral bracts tawny, brown, or bicolor; pistillate flowering branchlets 3-30 mm; stipules sometimes marcescent. | S. commutata |
89. Juvenile blades glabrous or pilose; largest medial blades: abaxial surface usually glabrous, pilose, or moderately densely short-silky, adaxial surface pilose or glabrous; floral bracts brown, black, or bicolor; pistillate flowering branchlets 1-10 mm; stipules deciduous (in autumn) | → 90 |
90. Largest medial blades 1.6-3.6 times as long as wide, elliptic to broadly so, abaxial surface glabrous or pilose, hairs white; floral bracts: apex acute to convex; stipes 0.2-1 mm. | S. arizonica |
90. Largest medial blades 2-5.2 times as long as wide, lorate, narrowly oblong, narrowly elliptic to elliptic or broadly so, abaxial surface pilose to densely short-silky, hairs white, sometimes also ferruginous, sometimes glabrous; floral bracts: apex rounded or retuse; stipes 0.5-2.5 mm. | S. boothii |
91. Largest medial blades: surfaces slightly or highly glossy adaxially | → 92 |
91. Largest medial blades dull adaxially | → 102 |
92. Floral bracts tawny | → 93 |
92. Floral bracts brown, black, or bicolor | → 95 |
93. Branches red-brown; stipules early deciduous. | S. pyrifolia |
93. Branches yellowish to yellow-brown or gray-brown; stipules deciduous (in autumn) | → 94 |
94. Largest medial blades with distinctly toothed margins; pistillate catkins slender to stout; juvenile blades pilose, villous or glabrous. | S. famelica |
94. Largest medial blades with entire or indistinctly toothed margins; pistillate catkins subglobose to stout; juvenile blades long-silky or glabrous. | S. lutea |
95. Largest medial blades usually with white and ferruginous hairs on midrib of adaxial surface | → 96 |
95. Largest medial blades with white hairs on midrib of adaxial surface (S. hookeriana may have some ferruginous hairs on surfaces but not restricted to midrib) | → 98 |
96. Juvenile leaves reddish; nw California, adjacent Oregon. | S. tracyi |
96. Juvenile leaves yellowish green; Alaska, Alberta, British Columbia, Idaho, Montana, Northwest Territories, Oregon, Wyoming, Yukon | → 97 |
97. Largest medial blades narrowly to broadly elliptic, or narrowly ovate to ovate; pistillate nectaries square or obovate; stipules on early leaves foliaceous; branches not glaucous; floral bracts: apex acute or rounded; Alaska, nw Northwest Territories, Yukon. | S. hastata |
97. Largest medial blades narrowly elliptic to elliptic; pistillate nectaries oblong or ovate; stipules on early leaves absent or rudimentary (sometimes foliaceous); branches strongly to weakly glaucous or not; floral bracts: apex rounded; cordillera in Alberta, British Columbia, Idaho, Montana, Oregon, Northwest Territories, Wyoming, Yukon. | S. farriae |
98. Floral bracts dark brown to black, 1.1-3.6 mm; styles 0.6-2.5 mm; largest medial blades 1.5-4.2 times as long as wide; stigmas usually slenderly or broadly cylindrical, 0.28-0.74 mm; anthers yellow | → 99 |
98. Floral bracts tawny to light brown, 0.6-1.6 mm; styles 0.1-0.6 mm; largest medial blades 2.6-7 times as long as wide; stigmas flat, abaxially non-papillose, tip round, or 2 plump lobes, 0.12-0.32 mm; anthers purple turning yellow | → 100 |
99. Largest medial blades: abaxial surface glabrous or glabrescent, hairs white, margins serrulate, slightly revolute or flat; branches flexible at base. | S. barclayi |
99. Largest medial blades: abaxial surface pilose, villous, tomentose, or woolly, hairs often white and ferruginous, margins entire, sinuate to serrulate, or crenate, slightly revolute; branches highly brittle at base. | S. hookeriana |
100. Branches usually red-brown, sometimes gray-brown (nw California, adjacent Oregon). | S. tracyi |
100. Branches yellowish or grayish | → 101 |
101. Largest medial blades with distinctly toothed margins; pistillate catkins slender to stout; juvenile blades pilose, villous, or glabrous. | S. famelica |
101. Largest medial blades with entire or indistinctly toothed margins; pistillate catkins subglobose to stout; juvenile blades long-silky or glabrous. | S. lutea |
102. Largest medial blades usually with some ferruginous hairs on midrib of adaxial surface | → 103 |
102. Largest medial blades with white hairs only on midrib of adaxial surface (S. hookeriana may have ferruginous hairs on adaxial surface but not restricted to midrib) | → 104 |
103. Largest medial blades narrowly to broadly elliptic or narrowly ovate to ovate; pistillate adaxial nectaries square or obovate; stipules on early leaves foliaceous; branches not glaucous; floral bracts: apex acute or rounded; Alaska, nw Northwest Territories, Yukon. | S. hastata |
103. Largest medial blades narrowly elliptic to elliptic; pistillate adaxial nectaries oblong or ovate; stipules on early leaves absent or rudimentary (sometimes foliaceous); branches strongly to weakly glaucous or not; floral bracts: apex rounded to convex; cordillera in Alberta, British Columbia, Idaho, Montana, Oregon, Wyoming. | S. farriae |
104. Largest medial blades amphistomatous | → 105 |
104. Largest medial blades usually hypostomatous, sometimes hemiamphistomatous | → 107 |
105. Branches pilose or villous; filaments hairy basally; ovaries: beak slightly bulged below styles. | S. turnorii |
105. Branches glabrous; filaments glabrous; ovaries: beak gradually tapering to styles | → 106 |
106. Styles 0.6-1.1 mm; juvenile blades villous to long-silky, with white, and sometimes ferruginous, hairs; largest medial blades 2-3.9 times as long as wide, abaxial surface glabrous; stipes 0.5-1.6mm. | S. monticola |
106. Styles 0.13-0.6 mm; juvenile blades glabrous or long-silky, hairs white; largest medial blades 2.8-5.6 times as long as wide, abaxial surface long-silky to pilose or glabrous; stipes 0.9-3.8 mm. | S. lutea |
107. Largest medial blades slightly glossy adaxially | → 108 |
107. Largest medial blades dull adaxially | → 109 |
108. Largest medial blades with distinctly toothed margins; pistillate catkins slender to stout; juvenile blades pilose, villous, or glabrous. | S. famelica |
108. Largest medial blades with entire or indistinctly toothed margins; pistillate catkins subglobose or stout; juvenile blades long-silky or glabrous. | S. lutea |
109. Branches yellow-gray, yellow-brown, or gray-brown; floral bracts tawny or brown; ovaries pyriform or ovoid. | S. lutea |
109. Branches usually red-brown, rarely yellow-gray or yellow-brown; floral bracts brown or black; ovaries pyriform | → 110 |
110. Styles 0.6-1.1 mm. | S. monticola |
110. Styles 0.2-0.7 mm | → 111 |
111. Largest medial blades lorate to narrowly elliptic, 2.9-6.4 times as long as wide, margins usually serrulate or serrate, rarely apparently entire; stipes 0.9-2.5 mm. | S. ligulifolia |
111. Largest medial blades narrowly oblong, lanceolate or obovate, 2.4-4.5 times as long as wide, margins prominently serrate, serrulate, or spinulose-serrulate; stipes 1.3-4.2 mm. | S. prolixa |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
