Colutea arborescens
Bladder senna
(c) Radio Tonreg, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Shrub / Tree · Not Native
Colutea arborescens (Bladder senna) is a non-native California shrub / tree in the Fabaceae family, recognized by European genus with limited naturalization; bladder senna represents the genus's only established presence in California.
Bladder senna is a naturalized shrub found in northern Sierra Nevada Foothills and southern Great Basin in woodland and disturbed areas at elevations below 1,600 meters. Flowering from May to August, this plant produces distinctive yellow flowers with dark markings approximately 1.5 to 2 centimeters long. Growing as a rounded deciduous shrub less than 3 meters tall with many branching stems, it develops a spreading, multi-stemmed form. Its compound leaves feature 9 to 13 elliptic leaflets, each 1.5 to 3 centimeters long and sparsely hairy. The plant produces unique bladder-like fruits 2 to 3 centimeters long with a distinctive stalk-like base.
Identification and appearance
Key characters: European genus with limited naturalization; bladder senna represents the genus's only established presence in California
Habitat and range
Habitat: Uncommon. Roadsides, woodland, disturbed areas
Elevation: < 1600 m
California counties: Los Angeles, Siskiyou, Alameda, Butte, Yolo
Outside California: introduced in United States, native to southern Europe
Bloom period
Colutea arborescens blooms May-Aug.
How to tell it apart
vs Sesbania: Colutea pods inflated like balloons; sesbania pods are long, flat, and narrow.; vs Cleomella: Colutea has pea flowers and compound leaves; cleomella has 4-petaled flowers and simple leaves.; vs Lupinus: Colutea has pinnate compound leaves; lupine has palmate leaves radiating like fingers.; vs Genista: Colutea pods are inflated balloons; Genista pods are flat and splitting.; vs Cytisus: Colutea pods are inflated balloons; Cytisus pods are flat and explosively dehiscent.
Frequently asked questions
Is Colutea arborescens native to California?
No. Colutea arborescens is not native to California (recorded as not native).
When does Colutea arborescens bloom?
Colutea arborescens blooms May-Aug.
Where in California does Colutea arborescens grow?
Colutea arborescens occurs in Los Angeles, Siskiyou, Alameda, Butte, Yolo, at elevations of < 1600 m.
What plant family does Colutea arborescens belong to?
Colutea arborescens is in the Fabaceae family, genus Colutea.
What habitat does Colutea arborescens grow in?
Colutea arborescens grows in Uncommon. Roadsides, woodland, disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.