Anthoxanthum odoratum
Sweet vernal grass
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Poaceae · Type: Grass · Not Native
Conservation status: Cal-IPC Yes
Anthoxanthum odoratum (Sweet vernal grass) is a non-native California grass in the Poaceae family, recognized by spike-like vs open inflorescence and perennial habit.
Sweet vernal grass is a naturalized perennial grass found in northern California coastal regions, Klamath Ranges, northern Coast Ranges, central Sierra Nevada, central Coast, and San Francisco Bay Area in meadows, pastures, forest openings, and disturbed sites at elevations generally below 1,600 meters. Flowering from May to June, this grass produces pale yellow to greenish flowers in dense, compact spike-like inflorescences 2 to 14 centimeters long. Growing with erect stems 30 to 60 centimeters tall, it has soft, slightly hairy stems with distinctive leaf characteristics. Its leaves have upper blades 3 to 6 centimeters long, 3 to 10 millimeters wide, with soft hairs and small auricles at the base of the blade. The plant's spikelets are 7 to 10 millimeters long with soft, colorless hairs at the base of the lemma.
Identification and appearance
Key characters: 2 sympatric species; distinguished by spike-like vs open inflorescence and perennial habit
Habitat and range
Habitat: Meadows, pastures, openings in conifer forest, disturbed sites
Elevation: generally < 1600 m
California counties: Humboldt, Del Norte, Mendocino, Placer, San Francisco, Santa Barbara, Sonoma, Nevada, Butte, Yolo, Trinity, Santa Cruz, Monterey, Lake, Fresno, El Dorado, Calaveras, Alameda, Marin, Plumas, Sacramento, Shasta, Yuba, Mariposa, Solano, San Luis Obispo, San Mateo, Tuolumne, Napa, Merced
Outside California: widespread United States, temperate, native to Europe
Bloom period
Anthoxanthum odoratum blooms May-Jun.
Conservation status
Cal-IPC Yes
How to tell it apart
vs Phalaris: Anthoxanthum spikelets have 2 awned sterile lemmas flanking a smaller fertile floret and smell sweet (coumarin) when dried; Phalaris (canary grass) has laterally flattened spikelets with scale-like sterile lemmas and no awns.; vs Alopecurus: Anthoxanthum's panicle is open to spike-like with 2-glumed awned spikelets; Alopecurus (foxtail) has a dense cylindric spike of 1-flowered spikelets with a single bent awn.; vs Phleum: Anthoxanthum spikelets are awned in a loose to spike-like head; Phleum (timothy) has a very dense, stiff cylindric spike of flat spikelets with short-awned glumes.; vs Holcus: Anthoxanthum is sweet-scented with awned sterile lemmas; Holcus (velvet grass) is softly velvety-hairy with a pale purple-tinged panicle and only a short hooked awn.; vs Agrostis: Anthoxanthum has conspicuous 2 sterile awned lemmas per spikelet; Agrostis (bentgrass) has tiny 1-flowered, essentially awnless spikelets in a diffuse open panicle.
Frequently asked questions
Is Anthoxanthum odoratum native to California?
No. Anthoxanthum odoratum is not native to California (recorded as not native).
When does Anthoxanthum odoratum bloom?
Anthoxanthum odoratum blooms May-Jun.
Where in California does Anthoxanthum odoratum grow?
Anthoxanthum odoratum occurs in Humboldt, Del Norte, Mendocino, Placer, San Francisco, Santa Barbara, Sonoma, Nevada and other counties, at elevations of generally < 1600 m.
What plant family does Anthoxanthum odoratum belong to?
Anthoxanthum odoratum is in the Poaceae family, genus Anthoxanthum.
Is Anthoxanthum odoratum invasive in California?
Anthoxanthum odoratum is listed by Cal-IPC with an invasiveness rating of Yes.
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.