TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

SALICACEAE

WILLOW FAMILY

Shrub, tree, generally dioecious (rarely monoecious)
Stem: trunk < 40 m; wood soft; bark smooth, bitter; buds scaly
Leaves simple, alternate, deciduous; stipules generally deciduous, often large
Inflorescence: catkin, generally appearing before leaves; each flower subtended by disk or 1–2 nectary glands and 1 bract
Flower: perianth 0
Staminate flower: stamens 1–many
Pistillate flower: pistil 1, ovary superior, chamber 1, stigma lobes 2–4
Seeds many; hairs fine, white, cottony
Fruit: capsule; valves 2–4
Genera in family: 2 genera, 340 species: generally temp (except Australia, Malay Archipelago) moist places; many cultivated. Hybridization common; identification often difficult. Family description, key to genera by John O. Sawyer, Jr.

SALIX

WILLOW

George W. Argus

Shrub, tree, dioecious; bud scale 1, not sticky, margins generally fused (or free, overlapping)
Stem: twigs generally flexible and not glaucous
Leaf: blade linear to widely obovate, entire to toothed, generally ± hairy
Inflorescence: dense catkin emerging before, with, or after leaves, sessile or on a short leafy shoot; bract subtending each flower
Flower: perianth 0
Staminate flower: stamens 1–8
Pistillate flower: ovary stalked or sessile, style 1 or 0, stigmas 2, each sometimes 2-lobed; nectaries 1–several, generally rod-like, generally between inflorescence axis and flower
Fruit: valves 2
Species in genus: ± 400 species: ± worldwide, especially n temp, arctic
Etymology: (Latin: ancient name)
Reference: [Argus 1986 Syst Bot Monog 9:1–170; Dorn 1976 Canad J Bot 54:2769–2789]
Difficult, highly variable. Not all specimens will key easily; sprout shoots and other extreme forms are not included in keys, may require field comparison for identification. Studies of variation, hybridization needed.

Native

S. arctica Pall.

ARCTIC WILLOW

Shrub < 0.1 m, trailing, rooting
Stem: twigs brownish, sparsely soft-shaggy-hairy
Leaves: stipules vestigial; young leaves long-soft-hairy; mature blade 20–40 mm, ± elliptic, acuminate (base acute to rounded), entire, sparsely soft-shaggy-hairy, becoming glabrous, lower surface glaucous
Inflorescence appearing with leaves, 9–55 mm, on leafy shoot 5–55 mm; flower bract tawny or dark brown
Staminate flower: stamens 2
Pistillate flower: ovary silky, style 0.4–1.6 mm, stalk 0.3–0.8 mm
Chromosomes: 2n=76,114
Ecology: Alpine tundra
Elevation: 2300–4000 m.
Bioregional distribution: High Cascade Range (Lassen Peak), c&s High Sierra Nevada
Distribution outside California: to n Canada, Nevada
Synonyms: S. anglorum Cham. vars. antiplasta C.K. Schneid. and petraea Andersson
Plants with narrow, sharp-pointed leaves approach S. cascadensis Cockerell of WA and n; need study
Horticultural information: WET: 1, 2, 3, 7, 18 &SUN: 4, 5, 6, 15, 16; DFCLT.