Bromus briziformis
Rattlesnake chess, Rattlesnake Chess
(c) Oleg Kosterin, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Not Native
Bromus briziformis (Rattlesnake chess) is a non-native California grass in the Poaceae family, recognized by inflated lemmas with raised veins diagnostic.
Rattlesnake chess is a naturalized annual grass found in the Klamath Ranges, northern Sierra Nevada, and Modoc Plateau in open places at elevations of 1,250 to 1,830 meters. Flowering from May to July, this grass produces nodding, open inflorescences with spikelets 15 to 27 millimeters long. Growing 17 to 70 centimeters tall with distinctively hairy leaf sheaths, it spreads in loose, delicate clusters. Its grass blades are 1.5 to 5 millimeters wide and covered in soft hairs, with tiny ligules measuring 0.5 to 2 millimeters long. Its inflated lemmas have strongly raised veins and barely noticeable teeth, giving the plant a soft, delicate appearance.
Identification and appearance
Key characters: 25 sympatric species; inflated lemmas with raised veins diagnostic
Habitat and range
Habitat: Open places
Elevation: 1250-1830 m
California counties: Modoc, Plumas, Amador, Lassen, Siskiyou, Humboldt, Marin, Tuolumne, Sonoma, Mendocino
Outside California: to Alaska, British Columbia, northeastern United States, native to Eurasia
Bloom period
Bromus briziformis blooms May-Jul.
How to tell it apart
vs Nassella: Bromus has closed leaf sheaths and large spikelets; Nassella has open sheaths and needle-like awns.; vs Hordeum: Bromus has separate large spikelets; Hordeum has three spikelets grouped at each node.; vs Avena: Bromus lemmas have two teeth at tip; Avena lemmas have a twisted awn from the back.; vs Lolium: Bromus spikelets are stalked in clusters; Lolium spikelets sit edgewise against the stem.; vs Festuca: Bromus leaf sheaths are closed; Festuca sheaths split open halfway down.
Frequently asked questions
Is Bromus briziformis native to California?
No. Bromus briziformis is not native to California (recorded as not native).
When does Bromus briziformis bloom?
Bromus briziformis blooms May-Jul.
Where in California does Bromus briziformis grow?
Bromus briziformis occurs in Modoc, Plumas, Amador, Lassen, Siskiyou, Humboldt, Marin, Tuolumne and other counties, at elevations of 1250-1830 m.
What plant family does Bromus briziformis belong to?
Bromus briziformis is in the Poaceae family, genus Bromus.
What habitat does Bromus briziformis grow in?
Bromus briziformis grows in Open places.
Related species
Other California species in the same genus, family, or bioregion.
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.