Rytidosperma racemosum
(c) Kym Nicolson, some rights reserved (CC BY), uploaded by Kym Nicolson · licence
Family: Poaceae · Type: Grass · Not Native
Rytidosperma racemosum is a non-native California grass in the Poaceae family, recognized by restricted range, hair tuft positioning, and leaf length.
Ryedge grass is a naturalized perennial grass found in northern central Coast Ranges, specifically in Alameda County, in disturbed areas at elevations below 200 meters. Flowering in June, this grass produces pale green to brown spikelets with delicate flower clusters 10 to 13 millimeters long. Growing with short rhizomes and reaching 20 to 60 centimeters tall, it forms dense clumps with slender stems. Its leaves are primarily basal, stretching 15 to 75 centimeters long and appearing flat or slightly rolled. The grass features distinctive lemmas with lateral lobes and a central awn 11 to 14 millimeters long that reflexes to reveal the palea tip.
Identification and appearance
Key characters: 2 sympatric species; key features are restricted range, hair tuft positioning, and leaf length
Habitat and range
Habitat: Disturbed areas
Elevation: < 200 m
Outside California: native to Australia, naturalized in New Zealand
Bloom period
Rytidosperma racemosum blooms Jun.
How to tell it apart
vs Melica: Rytidosperma has banded hairs in rows on seeds; Melica has a club-shaped cluster of sterile florets at spikelet tip.; vs Aira: Rytidosperma has large seeds with banded hairs; Aira is tiny with smooth or uniformly hairy seeds.; vs Vahlodea: Rytidosperma has hairs in distinct transverse rows; Vahlodea has scattered hairs without banded pattern.; vs Deschampsia: Rytidosperma has seeds with horizontal hair bands; Deschampsia has hairy spikelet axis extensions, not banded seed hairs.; vs Trisetum: Rytidosperma has banded seed hairs; Trisetum has uniformly hairy seeds and conspicuous bent awns.
Frequently asked questions
Is Rytidosperma racemosum native to California?
No. Rytidosperma racemosum is not native to California (recorded as not native).
When does Rytidosperma racemosum bloom?
Rytidosperma racemosum blooms Jun.
What plant family does Rytidosperma racemosum belong to?
Rytidosperma racemosum is in the Poaceae family, genus Rytidosperma.
What habitat does Rytidosperma racemosum grow in?
Rytidosperma racemosum grows in Disturbed areas.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.