Salix exigua

Nuttall

N. Amer. Sylv. 1: 75. 1842.

Synonyms: Salix fluviatilis var. exigua (Nuttall) Sargent Salix longifolia var. exigua (Nuttall) Bebb
Treatment appears in FNA Volume 7. Treatment on page 54. Mentioned on page 23, 51, 52, 53, 57.
Revision as of 22:16, 16 December 2019 by FNA>Volume Importer

Shrubs or trees, 0.5–5(–17) m. Stems: branches gray-brown, red-brown, or yellow-brown, villous, or tomentose to glabrescent; branchlets yellowish, yellow-brown, or red-brown, pubescent or puberulent, tomentose, short- or long-silky villous. Leaves: stipules absent or rudimentary on early ones, foliaceous or rudimentary on late ones; petiole 1–5(–10) mm, pubescent or puberulent, villous, or short-silky adaxially; largest medial blade (sometimes hypostomatous), linear or lorate, (glands marginal), 30–136–143 × 2–14 mm, 6.5–28(–37.5) times as long as wide, base cuneate, margins slightly revolute, entire or remotely spinulose-serrulate, apex acuminate or acute, abaxial surface glaucous (sometimes obscured by hairs), densely long-silky, villous or pilose to glabrescent, hairs appressed or spreading, straight or wavy, adaxial slightly glossy, sparsely or densely long-silky to glabrescent; proximal blade margins entire; juvenile blade yellowish green, densely long-silky-villous abaxially. Catkins: staminate 7–54 × 2–10 mm, flowering branchlet 1.5–56 mm; pistillate loosely to densely flowered, slender or stout, 14.5–70 × 3–12 mm, flowering branchlet 2–55 mm; floral bract 1.2–2.6 mm, apex acute, convex, or rounded, entire or erose, hairs wavy, straight, or crinkled, abaxially hairy throughout or proximally, or glabrate. Staminate flowers: abaxial and adaxial nectaries present and distinct; filaments hairy on proximal 1/2; anthers (sometimes reddish turning yellow). Pistillate flowers: adaxial nectary oblong, ovate, or flask-shaped, relative adaxial nectary/stipe length variable even within same catkin; stipe 0–0.9 mm; ovary obclavate or pyriform, glabrous, pilose, or villous, or sometimes beak hairy, beak bulged below or abruptly tapering to styles; ovules 12–30 per ovary; styles (sometimes distinct), 0–0.5 mm; stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes, 0.1–0.5 mm. Capsules 4–8 mm. 2n = 38.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Branchlets densely short-silky-tomentose or short-silky-villous; juvenile blades densely long-silky abaxially, hairs usually appressed, sometimes a few spreading; stipes 0.2-0.9 mm; styles connate, 0-0.2 mm; ovaries usually glabrous, sometimes beak hairy; stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes. Salix exigua var. exigua
1 Branchlets pubescent or densely long-silky-villous; juvenile blades densely long-silky-villous abaxially, hairs spreading, appressed; stipes 0-0.2 mm; styles connate or ± distinct, 0.1-0.5 mm; ovaries pilose or villous to glabrescent; stigmas flat, abaxially non-papillate with pointed tip, or slenderly cylindrical. Salix exigua var. hindsiana