Geranium core-core
Alderney crane's-bill
(c) Alan Prather, some rights reserved (CC BY) · licence
Family: Geraniaceae · Type: Perennial · Not Native
Geranium core-core (Alderney crane's-bill) is a non-native California perennial in the Geraniaceae family, recognized by beak lacking narrow tip.
Alderney crane's-bill is a naturalized perennial herb found in coastal and inland regions including North Coast, central California Coast, San Francisco Bay Area, western Southern California, and central Peninsular Ranges at elevations below 200 meters in disturbed sites. Flowering from March to October, this plant produces distinctive purple flowers with rounded or slightly notched petals measuring 3.1 to 7.1 millimeters long. Growing with ascending to erect stems 15 to 75 centimeters tall covered in sparse, stiff, reflexed hairs, it has a spreading habit. Its leaves are deeply divided into 5 to 7 broadly wedge-shaped segments, with blades 15 to 56 millimeters wide. The fruit develops mericarp segments 2.6 to 3.2 millimeters long with a narrow beak up to 14.5 millimeters in length.
Identification and appearance
Key characters: 19 sympatric species; distinguished by beak lacking narrow tip
Habitat and range
Habitat: Disturbed sites
Elevation: < 200 m
California counties: Ventura, Monterey, San Diego, Sonoma, Santa Barbara, Alameda, Contra Costa, San Luis Obispo, Santa Cruz, Mendocino, Butte, San Francisco, Humboldt, Marin, Del Norte
Outside California: native to South America
Bloom period
Geranium core-core blooms Mar-Oct.
How to tell it apart
vs Erodium: Geranium leaves are palmately divided like spread fingers; Erodium leaves are pinnately divided like a feather.; vs Pelargonium: Geranium is herbaceous with symmetrical flowers; Pelargonium is shrubby with asymmetrical flowers.; vs Sidalcea: Geranium has deeply palm-divided leaves; Sidalcea has shallowly palmately-lobed leaves and stamens fused in a column.; vs Bowlesia: Geranium has deeply divided leaves and pink flowers; Bowlesia has shallowly lobed leaves and tiny white umbel flowers.; vs Malva: Geranium has deeply palm-divided leaves with narrow segments; Malva has shallowly palmately-lobed leaves and fused stamens.
Frequently asked questions
Is Geranium core-core native to California?
No. Geranium core-core is not native to California (recorded as not native).
When does Geranium core-core bloom?
Geranium core-core blooms Mar-Oct.
Where in California does Geranium core-core grow?
Geranium core-core occurs in Ventura, Monterey, San Diego, Sonoma, Santa Barbara, Alameda, Contra Costa, San Luis Obispo and other counties, at elevations of < 200 m.
What plant family does Geranium core-core belong to?
Geranium core-core is in the Geraniaceae family, genus Geranium.
What habitat does Geranium core-core grow in?
Geranium core-core grows in Disturbed sites.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.