Eriochloa contracta
Prairie cup grass, Prairie Cup Grass
(c) Sam Kieschnick, some rights reserved (CC BY), uploaded by Sam Kieschnick · licence
Family: Poaceae · Type: Grass · Not Native
Eriochloa contracta (Prairie cup grass) is a non-native California grass in the Poaceae family, recognized by purple-tinged spikelets and generally 1 spikelet per node.
Prairie cup grass is a naturalized perennial grass found in the Central Valley, southwestern California, and desert regions of southern California in seasonal stream habitats at elevations below 100 meters. Flowering from August to October, this grass produces purple-tinged spikelets 3.5 to 4.5 millimeters long in delicate inflorescences. Growing with stems 20 to 100 centimeters tall, it has 2 to 5 distinctive nodes along its stem. Its leaf blades are generally 8 to 12 centimeters long and 2 to 8 millimeters wide, with short hairs on the upper surface. The spikelets develop with short stalks less than 1 millimeter long, creating a distinctive compact grass formation.
Identification and appearance
Key characters: 2 sympatric species; key features are purple-tinged spikelets and generally 1 spikelet per node
Habitat and range
Habitat: Seasonal streams
Elevation: < 100 m
California counties: Riverside, Glenn, Merced, Imperial, Yolo, Sutter, San Bernardino, Santa Barbara, Solano, Butte, Tehama, Kern, San Joaquin, Madera
Outside California: native to central and southern United States
Bloom period
Eriochloa contracta blooms Aug-Oct.
How to tell it apart
vs Echinochloa: Eriochloa has spikelets in cups; barnyard grass has bristly spikelets without cups.; vs Digitaria: Eriochloa has each spikelet in a cup; crabgrass has spikelets without basal cups.; vs Paspalum: Eriochloa has spikelets sitting in cups; dallisgrass has spikelets without any cup structure.; vs Panicum: Eriochloa has a distinctive cup under each spikelet; panicgrass spikelets lack cups.
Frequently asked questions
Is Eriochloa contracta native to California?
No. Eriochloa contracta is not native to California (recorded as not native).
When does Eriochloa contracta bloom?
Eriochloa contracta blooms Aug-Oct.
Where in California does Eriochloa contracta grow?
Eriochloa contracta occurs in Riverside, Glenn, Merced, Imperial, Yolo, Sutter, San Bernardino, Santa Barbara and other counties, at elevations of < 100 m.
What plant family does Eriochloa contracta belong to?
Eriochloa contracta is in the Poaceae family, genus Eriochloa.
What habitat does Eriochloa contracta grow in?
Eriochloa contracta grows in Seasonal streams.
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.