Salix humilis var. humilis

Common names: Prairie willow
IllustratedEndemic
Synonyms: Salix humilis var. hyporhysa Farwell Salix humilis var. keweenawensis (Andersson) B. L. Robinson & Fernald Salix humilis var. rigidiuscula
Treatment appears in FNA Volume 7. Treatment on page 129.

Mid shrubs, 0.3–3 m. Stems usually erect, sometimes decumbent; branches tomentose to glabrescent, peeled wood smooth or striate, striae sometimes very dense, to 20 mm; branchlets redbrown or greenish brown. Leaves: stipules usually foliaceous (rarely rudimentary) on late ones; petiole (1.5–) 3–7 (–12) mm, velvety or pilose adaxially; largest medial blade narrowly oblong, narrowly elliptic, elliptic, oblanceolate, obovate, or broadly obovate, (20–) 50–90 (–135) × (7–) 13–23 (–35) mm, 2.3–4–7.5 times as long as wide, margins strongly revolute to flat, abaxial surface with hairs rarely also ferruginous, adaxial slightly or highly glossy, glabrous, pubescent, or pilose (hairs white, sometimes also ferruginous); proximal blade margins usually entire, sometimes serrulate. Catkins: staminate 14.5–34 × 7–19 mm, flowering branchlet 0 mm; pistillate 9–47 (–55 in fruit) × 5.5–19 mm, flowering branchlet 0–4 mm; floral bract 1.2–2 mm. Staminate flowers: filaments glabrous. Pistillate flowers: ovary obclavate; stigmas 0.24–0.33–0.56 mm; ovules 6–12 per ovary. Capsules 7–12 mm. 2n = 38 and 76.


Phenology: Flowering (north) early Mar-early Jun, (south) late Jan-late Apr.
Habitat: Dry mixed woods and forests, Picea mariana-lichen woods, Picea glauca-Abies balsamea forests, wet to dry prairies, grassy balds, loess bluffs, sandy stream terraces, coastal barrens, Carex-Typha meadows, fine sand to rocky granitic, gneissic, limestone, and serpentine substrates
Elevation: 20-1600 m

Distribution

V7 137-distribution-map.gif

Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Va., W.Va., Wis.

Discussion

See 79. Salix scouleriana and 82. S. atrocinerea for comparative descriptions.

Hybrids:

Variety humilis forms natural hybrids with Salix bebbiana, S. discolor, S. eriocephala, and S. planifolia. Hybrids with S. discolor or S. planifolia often are suggested by glabrous or glabrate leaves.

Selected References

None.

Lower Taxa

None.

"-0.56mm" is not declared as a valid unit of measurement for this property.

21 +, 4 +, 1 +, 16 +  and 29 +
glaucous +  and sparsely densely tomentose or woolly +
square +  and oblong +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
pilose;pubescent;pilose;pubescent;glabrous +
purple turning yellow +
cylindrical +  and ellipsoid +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Acute (?) +, Rounded (?) +, Convex (?) +  and Acuminate (?) +
George W. Argus +
Marshall +
convex +  and cuneate +
Salix sect. Vetrix +
tapering +
ferruginous +  and white +
serrulate +  and entire +
densely tomentose +  and glabrescent +
toothed +  and 2-fid +
persistent +
dark redbrown +
tomentose +  and glabrescent +
flowered +  and pistillate +
0.9 cm9 mm <br />0.009 m <br /> (4.7 cm47 mm <br />0.047 m <br />) +
velvety-tomentose +  and glabrescent +
globose +  and subglobose +
slender +  and stout +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.55 cm5.5 mm <br />0.0055 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
intermediate +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
pistillate +  and staminate +
0.9 cm9 mm <br />0.009 m <br /> (4.7 cm47 mm <br />0.047 m <br />) +
pendulous +, spreading +  and erect +
0.55 cm5.5 mm <br />0.0055 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
Prairie willow +
Man. +, N.B. +, Nfld. and Labr. +, N.S. +, Ont. +, P.E.I. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Va. +, W.Va. +  and Wis. +
20-1600 m +
bicolor +, black +  and brown +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
pistillate +  and staminate +
bisexual +  and unisexual +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Dry mixed woods and forests, Picea marianaDry mixed woods and forests, Picea mariana-lichen woods, Picea glauca-Abies balsamea forests, wet to dry prairies, grassy balds, loess bluffs, sandy stream terraces, coastal barrens, Carex-Typha meadows, fine sand to rocky granitic, gneissic, limestone, and serpentine substratesssic, limestone, and serpentine substrates +
ferruginous +
straight +
spreading +  and erect +
unbranched +  and spicate +
subterminal +  and axillary +
membranaceous +
hemiamphistomatous +, amphistomatous +  and hypostomatous +
9 cm90 mm <br />0.09 m <br /> (13.5 cm135 mm <br />0.135 m <br />) +
2.3 cm23 mm <br />0.023 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
5 cm50 mm <br />0.05 m <br /> (9 cm90 mm <br />0.09 m <br />) +
obovate +, oblanceolate +, elliptic +  and oblong +
1.3 cm13 mm <br />0.013 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
arranged +  and alternate +
9 cm90 mm <br />0.09 m <br /> (13.5 cm135 mm <br />0.135 m <br />) +
2.3 cm23 mm <br />0.023 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
marcescent +
deciduous +
20mm;90mm +
obovate +, oblanceolate +, elliptic +  and oblong +
0.3 cm3 mm <br />0.003 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
strongly revolute +  and flat +
30 cm300 mm <br />0.3 m <br /> (300 cm3,000 mm <br />3 m <br />) +
2-7[-10]-carpellate +
short-silky-villous +
obclavate +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
glandular-dotted +
pilose +  and velvety +
convex;flat +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Flowering (north) early Mar-early Jun, (south) late Jan-late Apr. +
Arbust. Amer., +
overlapping +
distinct +
Illustrated +  and Endemic +
non-papillate +
cylindrical +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
caducous +  and persistent +
0 cm0 mm <br />0 m <br /> (2 cm20 mm <br />0.02 m <br />) +
distinct +  and connate +
persistent +  and deciduous +
Salix humilis var. hyporhysa +, Salix humilis var. keweenawensis +  and Salix humilis var. rigidiuscula +
Salix humilis var. humilis +
Salix humilis +
variety +
pointed +  and rounded +
sympodial +, branching +  and heterophyllous +
striate +  and smooth +