Amorpha californica var. napensis
Napa false indigo, Napa False Indigo, Napa false indigo, Napa false indigo
(c) John Hibbard, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Shrub · Native
Conservation status: CNPS 1B.2
Amorpha californica var. napensis (Napa false indigo) is a native California shrub in the Fabaceae family, recognized by glabrous habit and shorter calyx lobes.
Napa false indigo is a rare (CNPS 1B.2) California native shrub found in southern North Coast Ranges in Napa and Sonoma counties, and northern San Francisco Bay Area in Marin County, growing in chaparral habitats at elevations below 800 meters. Flowering from May to July, this plant produces purple flowers in dense clusters. Growing to approximately 1 to 2 meters tall with an upright, somewhat glabrous form, it develops woody stems that spread in a loose, open pattern. Its compound leaves have numerous dark green leaflets, each small and arranged pinnately along the stem. Its delicate purple flowers feature calyx lobes that are exceptionally short, measuring just 0.5 to 1 millimeter in length.
Identification and appearance
Key characters: 2 sympatric species; key features are glabrous habit and shorter calyx lobes
Habitat and range
Habitat: Chaparral
Elevation: < 800 m
Bloom period
Amorpha californica var. napensis blooms May-Jul.
Conservation status
CNPS 1B.2
How to tell it apart
vs Dalea: Amorpha flowers reduce to a single purple banner petal (no wings or keel) and its leaflets are gland-dotted; Dalea flowers retain more petal parts and it is generally a low herb or subshrub.; vs Astragalus: Amorpha is a woody shrub with erect spike-like clusters of 1-petaled flowers; Astragalus is an herb with normal banner-wing-keel pea flowers and an inflated or grooved pod.; vs Robinia: Amorpha bears dense erect spikes of tiny 1-petaled purple flowers and unarmed stems; black locust (Robinia) has drooping racemes of large white pea flowers and paired spines.; vs Colutea: Amorpha has narrow flower spikes and tiny 1--2-seeded gland-dotted pods; Colutea (bladder senna) has yellow pea flowers and large inflated papery pods.; vs Glycyrrhiza: Amorpha leaflets bear head-like glands and flowers keep only one petal; Glycyrrhiza has normal pea flowers and bur-like prickly pods.
Frequently asked questions
Is Amorpha californica var. napensis native to California?
Yes. Amorpha californica var. napensis is native to California (recorded as native).
When does Amorpha californica var. napensis bloom?
Amorpha californica var. napensis blooms May-Jul.
What plant family does Amorpha californica var. napensis belong to?
Amorpha californica var. napensis is in the Fabaceae family, genus Amorpha.
Is Amorpha californica var. napensis rare or endangered?
Amorpha californica var. napensis carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Amorpha californica var. napensis grow in?
Amorpha californica var. napensis grows in Chaparral.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
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.