Euclidium syriacum
Syrian mustard
(c) Konstantin Grebennikov, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Not Native
Euclidium syriacum (Syrian mustard) is a non-native California herb in the Brassicaceae family, recognized by Eurasian genus with specialized fruit structure; represents different adaptive strategy within Brassicaceae.
Syrian mustard is a naturalized annual found in the Mojave Province in disturbed pastures and roadsides at elevations of 1,000 to 1,500 meters. Flowering from May to June, this plant produces small white flowers in spike-like clusters with petals approximately 1 millimeter long. Growing with rigid, branched stems 40 to 45 centimeters tall and covered in minutely stalked, forked hairs, the plant has a distinctive hairy appearance. Its leaves range from 2 to 9 centimeters long, varying from oblong to lance-oblong with entire or slightly dentate margins. The fruit is a small woody silicle, ovoid and about 2 to 2.5 millimeters wide, typically containing two seeds.
Identification and appearance
Key characters: Eurasian genus with specialized fruit structure; represents different adaptive strategy within Brassicaceae
Habitat and range
Habitat: Disturbed pastures, roadsides
Elevation: 1000-1500 m
Outside California: to Washington, Colorado, native to Eurasia
Bloom period
Euclidium syriacum blooms May-Jun.
How to tell it apart
vs Dithyrea: Euclidium has microscopic petals (under 1.3mm); Dithyrea has large showy petals (10-15mm).; vs Alyssum: Euclidium fruits are plump and three-dimensional; Alyssum fruits are flat and disc-like from early development.; vs Smelowskia: Euclidium has simple entire leaves and closed fruits; Smelowskia has divided pinnate leaves.; vs Descurainia: Euclidium has simple undivided leaves; Descurainia has finely divided fern-like leaves.; vs Lobularia: Euclidium fruits never split open; Lobularia fruits split open to release seeds, plus has white/purple flowers.
Frequently asked questions
Is Euclidium syriacum native to California?
No. Euclidium syriacum is not native to California (recorded as not native).
When does Euclidium syriacum bloom?
Euclidium syriacum blooms May-Jun.
What plant family does Euclidium syriacum belong to?
Euclidium syriacum is in the Brassicaceae family, genus Euclidium.
What habitat does Euclidium syriacum grow in?
Euclidium syriacum grows in Disturbed pastures, 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.