Agrostis lacuna-vernalis
Vernal pool bent grass, Vernal Pool Bent Grass, vernal pool bent grass, vernal pool bent grass
(c) Mike Heine, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 1B.1
Agrostis lacuna-vernalis (Vernal pool bent grass) is a native California grass in the Poaceae family, recognized by extreme geographic restriction to single location and CNPS 1B.1 status.
Vernal pool bent grass is a rare (CNPS 1B.1) California native annual found in central Coast Ranges (Monterey County) in vernal pools at elevations below 200 meters. Flowering from April to May, this plant produces delicate pale green to white flowers in small, dense inflorescences up to 7.5 centimeters long. Growing 1.5 to 30 centimeters tall with slender, delicate stems, it forms compact, fine-textured clusters in seasonal wetland habitats. Its leaves are narrow, ranging from 1.4 to 11 centimeters long and 0.3 to 1.5 millimeters wide, typically flat or loosely rolled with a short ligule 1.2 to 1.7 millimeters long. The plant's small spikelets feature smooth glumes with acute tips and glabrous lemmas, creating a subtle, intricate grass structure characteristic of ephemeral vernal pool environments.
Identification and appearance
Key characters: 11 sympatric species; key features are extreme geographic restriction to single location and CNPS 1B.1 status
Habitat and range
Habitat: Vernal pools
Elevation: < 200 m
California counties: Monterey
Bloom period
Agrostis lacuna-vernalis blooms Apr-May.
Conservation status
CNPS 1B.1
How to tell it apart
vs Oloptum: Oloptum has prominent bent awns; Agrostis awns are tiny or absent.; vs Holcus: Holcus has velvety-hairy spikelets; Agrostis spikelets are smooth and glossy.; vs Polypogon: Polypogon has dense bristly panicles; Agrostis panicles are airy and delicate.; vs Poa: Poa has boat-shaped lemmas with 5 veins; Agrostis lemmas are rounded with faint veins.; vs Festuca: Festuca has multiple flowers per spikelet; Agrostis has single-flowered spikelets.
Frequently asked questions
Is Agrostis lacuna-vernalis native to California?
Yes. Agrostis lacuna-vernalis is native to California (recorded as native).
When does Agrostis lacuna-vernalis bloom?
Agrostis lacuna-vernalis blooms Apr-May.
Where in California does Agrostis lacuna-vernalis grow?
Agrostis lacuna-vernalis occurs in Monterey, at elevations of < 200 m.
What plant family does Agrostis lacuna-vernalis belong to?
Agrostis lacuna-vernalis is in the Poaceae family, genus Agrostis.
Is Agrostis lacuna-vernalis rare or endangered?
Agrostis lacuna-vernalis carries California Rare Plant Rank 1B.1, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.