Common Name: WILLOW FAMILY
Habit: Shrub, tree; dioecious (monoecious). Stem: trunk < 40 m; wood soft; bark smooth, bitter; buds scaly. Leaf: simple, alternate, deciduous; stipules generally present, deciduous or not, often large. Inflorescence: catkin [or various, or flowers 1]; each flower subtended by 1 bract. Flower: perianth modified into non-nectariferous, cup- or saucer-shaped structure or reduced to adaxial nectary (rarely also with abaxial nectary, then free or fused into shallow cup). Staminate Flower: stamens 2--many. Pistillate Flower: pistil 1, ovary superior to 1/2-inferior, chambers generally 2--4, placentas parietal, stigma lobes 2--4. Fruit: berry, drupe, or 2--4-valved capsule. Seed: often with basal tuft of hairs.
Genera In Family: 58 genera, 1210 species: widespread in tropics, northern temperate, arctic. Note: Now including many genera (e.g., Flacourtia, Idesia, Xylosma) formerly in Flacourtiaceae, at least in part because of presence on leaf margins in both families of salicoid teeth (vein extending to tooth tip). In California (and generally outside California), Populus pollinated by wind, Salix by insects, wind. Hybrids common; identification often difficult.
eFlora Treatment Author: John O. Sawyer, Jr., except as noted
Scientific Editor: Thomas J. Rosatti.
Common Name: WILLOW
Habit: Shrub, tree; dioecious; bud scale 1, not sticky, margins generally fused (or free, overlapping). Stem: twigs generally flexible, generally not glaucous. Leaf: generally alternate; stipules generally vestigial on first leaves, leaf-like on later; mature blade linear to broadly obovate, entire to toothed, generally +- hairy; petiole glands generally 0. Inflorescence: catkin, blooming before, with, or after leaves, sessile or terminating +- short leafy or bracted shoot ("on leafy shoot" or "on bracted shoot," "catkin length" including leafless or bractless part of subtending shoot); 1 flower bract subtending each flower, deciduous or persistent, brown, black, or 2-colored (paler proximally, darker distally; darker generally +- brown). Flower: perianth reduced to adaxial nectary (rarely also with abaxial nectary, then free or fused into shallow cup). Staminate Flower: stamens (1)2(10); nectary generally 1. Pistillate Flower: ovary stalked or sessile, style generally 1, stigmas 2, each 2-lobed, deciduous or persistent; nectary generally 1, generally rod-like. Fruit: valves 2.
Species In Genus: +- 450 species: +- worldwide, especially northern temperate, arctic. Etymology: (Latin: ancient name) Note: Difficult, highly variable, many hybrids. Not all specimens key easily; sprouts, other extreme forms not included in keys, may require field comparisons. Studies of chromosome numbers, hybridization needed. Inclusion of Salix sessilifolia Nutt. in TJM (1993) based on misidentification of plants belonging to Salix melanopsis. Fruit length as given throughout excludes the stalk (stipe). Hair lengths: minute, < +- 0.5 mm; short, +- 0.5 mm; long, > +- 0.5 mm. Salix commutata Bebb, treated as misapplied to Salix eastwoodiae in TJM (1993), may occur in northern California mountains; Salix bonplandiana expected in s-most California. For alternate treatments, see Dorn (e.g., 2000 Brittonia 52:1--19).
eFlora Treatment Author: George W. Argus