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	©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. exigua Nutt.

NARROW-LEAVED WILLOW

Shrub < 7 m, clonal by root-sprouting
Stem: twigs brownish, silky or long-soft-wavy-hairy, becoming glabrous
Leaves: stipules 0 or vestigial; petiole short; young leaves silky; mature blade 50–124 mm, linear, acuminate (base wedge-shaped), entire to sharply serrate (teeth well separated), silky, glaucous below or not
Inflorescence appearing with or after leaves, sometimes branched, 22–70 mm, on leafy shoots 5–110 mm; flower bract tawny; pistillate bract deciduous after flower
Staminate flower: stamens 2
Pistillate flower: ovary glabrous, silky, or sparsely soft-shaggy-hairy, stigma deciduous after flower, style 0–0.2 mm, stalk 0.2–1 mm
Chromosomes: 2n=38
Ecology: Common. Streamsides, marshes, wet ditches
Elevation: < 2700 m.
Bioregional distribution: California
Distribution outside California: to Alaska, e N.America, Arizona, Mexico
Flowering time: Mar–May
Synonyms: var. stenophylla (Rydb.) C.K. Schneid.; S. hindsiana Benth. including vars. leucodendroides (Rowlee) C.R. Ball and parishiana (Rowlee) C.R. Ball
Plants with spreading hairs on leaves and twigs, slender stigmas 0.6–1 mm, and ± entire leaves from throughout CA have been called S. hindsiana Benth.; these features vary independently; the type of S. h. Benth. does not share them all. Such forms may be derived from S. e. Nutt. X S. sessilifolia Nutt.; further study needed
Horticultural information: WET, SUN: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24; STBL.