Cardamine hirsuta
Hairy bitter cress
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Brassicaceae · Type: Herb · Not Native
Cardamine hirsuta (Hairy bitter cress) is a non-native California herb in the Brassicaceae family, recognized by annual habit, basal rosette, and small size diagnostic.
Hairy bitter cress is a naturalized annual found in the Klamath Ranges and central Coast Ranges in disturbed areas, roadsides, and fields at elevations below 800 meters. Flowering from February to July, this plant produces small white flowers with petals 2.5 to 4.5 millimeters long. Growing with erect stems 10 to 35 centimeters tall and stiff hairs below, it forms a distinctive basal rosette of leaves. Its leaves have 4 to 7 pairs of leaflets, with terminal leaflets larger than lateral ones, ranging from kidney-shaped to nearly round and measuring 0.6 to 3 centimeters wide. The fruit is an erect pod 1.5 to 2.5 centimeters long, containing 14 to 40 small oblong seeds.
Identification and appearance
Key characters: 8 sympatric species; annual habit, basal rosette, and small size diagnostic
Habitat and range
Habitat: Disturbed areas, roadsides, fields
Elevation: < 800 m
Outside California: to British Columbia, eastern North America, native to Europe
Bloom period
Cardamine hirsuta blooms Feb-Jul.
How to tell it apart
vs Raphanus: Cardamine has narrow pencil-like pods with many seeds; Raphanus has thick beaked pods that break into segments.; vs Nasturtium: Cardamine grows on moist land in shade; Nasturtium grows in or at the edge of water in sun.; vs Viola: Cardamine has four petals and thin seed pods; Viola has five petals and a capsule that splits into three parts.; vs Vancouveria: Cardamine has four-petaled flowers and seed pods; Vancouveria has six-petaled flowers and follicles.; vs Lepidium: Cardamine has narrow pods with many seeds; Lepidium has flattened round pods with only 2 seeds.
Frequently asked questions
Is Cardamine hirsuta native to California?
No. Cardamine hirsuta is not native to California (recorded as not native).
When does Cardamine hirsuta bloom?
Cardamine hirsuta blooms Feb-Jul.
What plant family does Cardamine hirsuta belong to?
Cardamine hirsuta is in the Brassicaceae family, genus Cardamine.
What habitat does Cardamine hirsuta grow in?
Cardamine hirsuta grows in Disturbed areas, roadsides, fields.
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.