Skip to main content

Toxicodendron rydbergii - western poison ivy

Scientific Family
Anacardiaceae
Synonyms
Rhus radicans, Rhus toxicodendron, Toxicodendron crenatum, Toxicodendron desertorum, Toxicodendron radicans, Toxicodendron volubile
Plant type
Shrubs
Riparian
Yes

Plant Description

Origin
Native

Erect shrub or ascending, single-stalked or few-branched, forming colonies by runners. It lacks aerial roots so does not climb like the eastern species. All parts have an oil skin irritant that causes a severe reaction in many individuals.

Shrub or subshrub; stems erect, single-stalked or few-branched; alternate compound leaves near ends of stems, 3 stalked leaflets; flower 5 yellowish-white petals and 5 stamens with yellow tips; fruit round, white berry. Rhizomatous.

Height
2 feet
Width
Varies depending on support

Habitat

Habitat description

Found in moist but often sunny sites in canyons, along streams and at seeps and springs from the low desert to mixed conifer forests.

Plant Community
Riparian
Low elevation
3000
High elevation
8000

Leaves

Leaf color
Dark Green
Leaf type
Compound
Leaf shape
Round or oval
Leaf margin
Toothed
Leaf attachment
Alternate
Leaf hairs
None
Spines
No
Leaf Drop
Deciduous

Dark green, compound, divided into 3 leaflets, usually shiny, oblong to lance-shaped to oval, notched or toothed, 4 inches long with red tinge when immature. Turns reddish-orange in fall.

Flowers

Flower color
Yellowish-white, greenish
Flower shape
Regular
Tubular
No
First bloom month
April
Last bloom month
September

Flowers are 1/4 inch wide in loose clusters to 3 inches long in lower leaf axils, each cluster usually having fewer than 25 flowers. Greenish sepals.

Flower clusters
Rounded

Fruit

Fruit color
White to yellowish-white
Fruit type
Berry-like

Cluster of 1/4 inch berry-like fruits.

Bark/Branches

Bark color
Light brown
Bark texture
Rough

Light brown woody stems.