Neostapfia colusana
Colusa grass
(c) Konshau Duman, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 1B.1 · Threatened
Neostapfia colusana (Colusa grass) is a native California grass in the Poaceae family, recognized by Endemic genus representing ancient grass lineage specialized for vernal pool environments of Central Valley.
Colusa grass is a rare (CNPS 1B.1) California native annual found in the Great Valley bioregion in Colusa, Merced, Solano, and Stanislaus counties, inhabiting vernal pools at elevations below 125 meters. Flowering from May to August, this delicate grass produces pale translucent flowers in dense, cylindric spike-like inflorescences 2 to 8 centimeters long. Growing with ascending stems 10 to 30 centimeters tall, the plant becomes brown and sticky-glandular with age. Its leaves are 5 to 12 millimeters wide, with a continuous sheath loosely enclosing the stem base. The fruit is approximately 2.5 millimeters long, with each spikelet typically containing five florets arranged along a breaking axis.
Identification and appearance
Key characters: Endemic genus representing ancient grass lineage specialized for vernal pool environments of Central Valley
Habitat and range
Habitat: Vernal pools
Elevation: < 125 m
California counties: Stanislaus, Merced, Solano, Colusa, Yolo
Bloom period
Neostapfia colusana blooms May-Aug.
Conservation status
CNPS 1B.1 · Threatened
Frequently asked questions
Is Neostapfia colusana native to California?
Yes. Neostapfia colusana is native to California (recorded as native).
When does Neostapfia colusana bloom?
Neostapfia colusana blooms May-Aug.
Where in California does Neostapfia colusana grow?
Neostapfia colusana occurs in Stanislaus, Merced, Solano, Colusa, Yolo, at elevations of < 125 m.
What plant family does Neostapfia colusana belong to?
Neostapfia colusana is in the Poaceae family, genus Neostapfia.
Is Neostapfia colusana rare or endangered?
Neostapfia colusana 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.