Go to: Keys to Identifying Selected Plant Groups in the SGMWillow Primer for the San Gabriel Mountains
Key
Descriptions
SourcesTrees and shrubs in the willow genus are identified by long, slender leaves growing alternately along the stem and by a single, large scale capping the flower bud in winter. The flowers are catkins; male and female flowers grow on separate plants. In the San Gabriel Mountains, willows grow where there is moisture, often indicating underground water courses in the canyons or seeps and springs on the mountainsides. These trees and shrubs provide some of our best and brightest, most long-lasting fall color.
View a panoramic picture of an assortment of willows and other trees in fall at Chino Hills State Park.
Key
What to look for
You need only a twig with a winter bud scale and a leaf to identify the willows below ~5500 feet elevation. Above that elevation in the San Gabriel Mountains, you need flowers to distinguish two of the species. Most of our willows are not totally deciduous. If you find one that is, look on the ground for a fallen leaf.
- First, look for the winter bud scale on the twig. It is the part that is found between the leaf stem and the twig it is attached to. Is the bud scale very sharply pointed at the tip or is it rounded in a capped cylinder? Drawing
- Next, look at the leaf. Is it white underneath or not?
- Now, feel for the glands where the leaf blade meets the leaf stalk (petiole). They feel like tiny rough bumps. Drawing; picture
- Finally, look at the shape of the leaf. Is it linear, that is, very long and slender [is the length 10 - 23 times the width]? Drawing
This primer includes all cismontane southern California species found below ~5500 feet, as well as Salix scouleriana, the most common species found above that elevation. It includes all species found in the San Gabriel Mountains, with the possible exception of Salix melanopsis, vouchered from three locations (Chilao, Swartout Valley, and near the head of San Antonio Canyon) from 5300 to 7500 feet. The Jepson Manual does not place this species in southern California; we speculate that these might be misidentified S. exigua, since these two species are distinguished only by minute details in the Munz key.
Simple willow key following the Jepson Manual:
Winter bud scale is very sharply pointed and overlappingLeaf is not glaucous (white) underneath = Salix gooddingii, black willowWinter bud scale is fused into a cylinder and blunt tipped
Leaf is glaucous (white) underneath = Salix laevigata, red willowPetiole (leaf stalk) with glands at the base of the blade = Salix lucida var. lasiandra, shining willow
Petiole without glandsLeaf is linear, generally less than 1 cm wide (1 cm is about the width of the fingernail on the little finger of most adults) = Salix exigua, narrowleaf willow
Leaf more than 1 cm wideAll elevations; ovary glabrous; thin edge of leaf margin flat to moderately minutely rolled under = Salix lasiolepis, arroyo willow
Elevations above 5500 feet; ovary hairy; thin edge of leaf margin moderately to strongly minutely rolled under = Salix scouleriana, Scouler's willow
Descriptions
Salix exigua (including Salix hindsiana); another link
- Common names: narrowleaf willow, sandbar willow, Hind's willow; exigua=short
- Leaf: shape=linear; base=wedge (acute); tip=short pointed; edge=shallow, widely spaced teeth; color=gray-green, same on both sides; texture=silky or smooth; leafstalk=very short; fall color; another image
- Flower: color=yellow; female showing fruit
- Bark: color=light brown; young twigs=reddish brown, smooth
- Profile: shrub, forming thickets; another image
- Elevation range: between 0 and 5500 feet
- Locations: Castaic Creek, Dalton Canyon, Eaton Canyon, Lower San Gabriel Canyon, San Francisquito Canyon, Soledad Canyon, Big Tujunga Canyon, unspecified Angeles National Forest
- Comments: skinniest leaf of all local willow species; can be confused with mule fat which has flowers, not catkins, and no leafstalk
- Number of records: 10
- Links: USFS Fire Effects Database Tree List Description
Salix gooddingii ; another link
- Common names: black willow, Goodding's black willow, Goodding's willow
- Leaf: shape=widest at base, tapering to a point; tip=very long pointed, gently curved; color=green on both sides ; edge=many, closely spaced, rounded teeth; a drawing and another image
- Flower: color=yellow; male; female; bud scale=sharply pointed, yellow
- Bark: color=gray-brown; texture=furrowed; young twig color=yellowish
- Profile: tree, sometimes shrubby; irregular; not dense; another image
- Elevation range: between 0 and 2000 feet
- Locations: Eaton Canyon, Piru Pond, unspecified Angeles National Forest
- Comments: only local willow species with leaf that is the same color on both sides and with long pointed tip; other species have two-toned leaves or are very slender and with a short pointed tip
- Number of records: 2
- Links: USFS Fire Effects Database Tree List Description
- Common name: red willow; laevigata=smooth
- Leaf: shape=broader at the base, tapering to a point; tip=long pointed; edge=very finely toothed; color=green on top, whitish on the bottom; a drawing
- Flower: color=yellow; male; female showing fruit; bud scale sharply pointed
- Bark: color=gray; texture=rough, furrowed; young twig color=red to yellow brown
- Profile: tree or large shrub; dense; often appearing whitish from the backs of the leaves; and a show of fall color
- Elevation range: between 0 and 5000 feet
- Locations: Colby Ranch, Eaton Canyon, Lower San Gabriel Canyon, Pallett Creek, San Francisquito Canyon, Tanbark Flats, Tujunga Canyon, unspecified Angeles National Forest
- Comments: only local willow species with two-toned leaf and sharply pointed bud scale; other willows with two-toned leaves have round tipped bud scales (arroyo and shining)
- Number of records: 18
Salix lasiolepis; another link
- Common name: arroyo willow; lasiolepis=woolly scale
- Leaf: shape=symmetric or broader across the top half, often slightly curved; tip=short point or none; edge=flat to moderately minutely inrolled; color=green on top, whitish on the bottom; a drawing
- Flower: color=yellow; female showing fruit; bud scale=rounded, yellowish or reddish
- Bark: color=light brown; texture=smooth; young twig color=yellowish or reddish to yellow gray-brown, often on the same twig!
- Profile: shrub or small tree; dense; appears shiny
- Elevation range: between 0 and 9000 feet
- Locations: Arroyo Seco, Barley Flats, Big Rock Creek, Charlton Flats, Dalton Canyon, Dawson Saddle, Eaton Canyon, San Gabriel Canyon, unspecified Angeles National Forest
- Comments: buds and leaves seem to be more densely spaced along the off shoots than other species; difficult to distinguish from Scouler's willow without flowers. See Big Horn Mine Trail and Devils Slide Trail.
- Number of records: 24
Salix lucida ssp. lasiandra (=Salix lasiandra)
- Common names: shining willow, Pacific willow; lucida=shining, lasiandra=woolly stamen
- Leaf: shape=wider at the base, tapering to a point; tip=long pointed; edge=very finely toothed; color=green on top, whitish below; leafstalk=long, yellow, with glands; a drawing
- Flower: color=yellow
- Bark: color=brown; texture=rough; young twig color=purple to yellow
- Profile: tree or shrub
- Elevation range: between 0 and 8000 feet
- Locations: Dalton Dam, Lower San Gabriel Canyon, unspecified Angeles National Forest
- Comments: only local willow species with glands (minute rough bumps) on the leafstalk
- Number of records: 8
- Links: USFS Fire Effects Database Tree List Description
- Common names: Scouler's willow, Nuttall willow, fire willow, western pussy willow
- Leaf: shape=narrowly tapered at the base and widest near the tip; tip=usually blunt; edge=mostly without teeth, wavy, moderately to strongly minutely rolled under; color=dark green on top, whitish below, yellowish-green midrib; leafstalk=velvety; leaves arranged in a fanlike fashion at the tips of the branchlets; reddish-brown hairs mixed with silvery ones on one or both surfaces; another image
- Flower: color=yellow; looks like a "pussy willow"
- Bark: color=gray becoming brown; texture=smooth becoming rough; young twig color=yellow to dark; droopy
- Profile: here in the San Gabriels, a shrub
- Elevation range: between 0 and 10000 feet; however, in the eastern San Gabriels, it is found in elevations above 5500 feet
- Locations: Icehouse Canyon, near Big Pines, near Mount Baldy, San Sevaine Flats
- Comments: Difficult to distinguish from arroyo willow without flowers. See Big Horn Mine Trail and Devils Slide Trail.
- Number of records: 8
- Links: USFS Fire Effects Database Tree List Description
Sources and Other Web Information
A California Flora by Philip A. Munz, University of California Press, 1968.
A Field Guide to Western Trees by George A. Petrides, Houghton Mifflin Co., 1992.
The Jepson Manual Higher Plants of California edited by James C. Hickman, University of California Press, 1993.
Copyright © 2000-2007 by Jane Strong and Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
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Comments and feedback: Jane Strong | Tom Chester
Updated 14 January 2007
