Medicago orbicularis
Blackdisk medick
(c) Emanuele Santarelli, some rights reserved (CC BY-SA), uploaded by Emanuele Santarelli · licence
Family: Fabaceae · Type: Herb · Not Native
Medicago orbicularis (Blackdisk medick) is a non-native California herb in the Fabaceae family, recognized by bristle-like stipules and smooth, disk-like fruits diagnostic.
Blackdisk medick is a naturalized annual found in the Central Coast and San Francisco Bay Area in disturbed areas and roadsides at elevations below 500 meters. Flowering from March to June, this plant produces yellow flowers with a distinctive dark purple spot on the banner petal, small and delicate in clusters of one to five blossoms. Growing with spreading, mat-forming stems that are nearly hairless, it reaches a low-growing form across the ground. Its leaves feature small obovate leaflets about 1 to 1.5 centimeters long, with stipules divided into a cluster of bristles. The fruit is distinctive, forming a coiled disk-like shape with 3 to 7 loose turns, ranging in color from tan to black and appearing papery.
Identification and appearance
Key characters: 5 sympatric species; bristle-like stipules and smooth, disk-like fruits diagnostic
Habitat and range
Habitat: Uncommon. Disturbed areas, roadsides
Elevation: especially < 500 m
Outside California: sporadic elsewhere in United States, Oklahoma, Florida, native to Mediterranean, northern Africa
Bloom period
Medicago orbicularis blooms Mar-Jun.
How to tell it apart
vs Melilotus: Medicago fruits are spirally coiled; Melilotus fruits are small egg-shaped pods with transverse ridges.; vs Trifolium: Medicago flowers fall off; Trifolium flowers persist and enclose the fruit in papery covering.; vs Oxalis: Medicago has pea-shaped flowers and coiled fruits; wood-sorrels (Oxalis) have 5-petaled flowers and upright capsules.; vs Acmispon: Medicago has toothed leaflets and coiled fruits; Acmispon has smooth-edged leaflets and straight pods.; vs Vicia: Medicago has coiled prickly fruits; vetches (Vicia) have flat straight pods and tendrils.
Frequently asked questions
Is Medicago orbicularis native to California?
No. Medicago orbicularis is not native to California (recorded as not native).
When does Medicago orbicularis bloom?
Medicago orbicularis blooms Mar-Jun.
What plant family does Medicago orbicularis belong to?
Medicago orbicularis is in the Fabaceae family, genus Medicago.
What habitat does Medicago orbicularis grow in?
Medicago orbicularis grows in Uncommon. Disturbed areas, roadsides.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.