Lappula squarrosa
Two-rowed stickseed, Two-Rowed Stickseed
(c) Matt Lavin, some rights reserved (CC BY) · licence
Family: Boraginaceae · Type: Herb · Not Native
Lappula squarrosa (Two-rowed stickseed) is a non-native California herb in the Boraginaceae family, recognized by distinctive multi-rowed prickle arrangement.
Two-rowed stickseed is a naturalized annual found in southern California and the Sacramento Valley in moist, disturbed areas at elevations below 200 meters. Flowering from May to July, this plant produces small blue flowers approximately 2 to 3 millimeters in diameter. Growing with stems 15 to 80 centimeters tall, it develops slender, spreading branches. Its leaves are narrow and linear to oblong, measuring 2 to 5 centimeters long. The fruit consists of small nutlets with marginal prickles arranged in two distinct rows.
Identification and appearance
Key characters: Geographically isolated; distinctive multi-rowed prickle arrangement
Habitat and range
Habitat: Moist, disturbed areas
Elevation: < 200 m
Outside California: to eastern Washington, southern Idaho, northern Utah, naturalized in northern North America, Canada, native to Eurasia
Bloom period
Lappula squarrosa blooms May-Jul.
How to tell it apart
vs Cryptantha: Lappula seeds have marginal barbs; Cryptantha seeds are smooth without hooks.; vs Pectocarya: Both have barbed seeds, but Lappula seeds sit in deep cups; Pectocarya seeds are flat combseeds.; vs Plagiobothrys: Lappula seeds have hooked barbs on margins; Plagiobothrys seeds are smooth-edged.; vs Amsinckia: Lappula has tiny white flowers and barbed seeds; Amsinckia has orange-yellow flowers and smooth seeds.; vs Hackelia: Lappula fruit stalks stay upright; Hackelia stalks curve downward in fruit.
Frequently asked questions
Is Lappula squarrosa native to California?
No. Lappula squarrosa is not native to California (recorded as not native).
When does Lappula squarrosa bloom?
Lappula squarrosa blooms May-Jul.
What plant family does Lappula squarrosa belong to?
Lappula squarrosa is in the Boraginaceae family, genus Lappula.
What habitat does Lappula squarrosa grow in?
Lappula squarrosa grows in Moist, disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
- Lappula redowskii — Redowski's stickseed
- Lappula redowskii var. cupulata — Crowned stickseed
- Lappula redowskii var. redowskii — Western stickseed
- Lappula sp.
- Lithospermum arvense — Gromwell
- Lithospermum californicum — California stoneseed
- Lithospermum incisum — Plains stoneseed
- Lithospermum ruderale — Western stoneseed
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.