Danthonia decumbens
Mountain heath grass
(c) Christian Berg, some rights reserved (CC BY), uploaded by Christian Berg · licence
Family: Poaceae · Type: Grass · Not Native
Danthonia decumbens (Mountain heath grass) is a non-native California grass in the Poaceae family, recognized by readily distinguished by awnless lemmas and non-native status.
Mountain heath grass is a naturalized perennial found in northern Coast Ranges in disturbed marshy sites at elevations below 10 meters. Flowering from June to July, this grass produces small, delicate flowers in compact raceme-like clusters. Growing with erect or occasionally decumbent stems 8 to 60 centimeters tall, it has primarily basal leaves that are narrow and fine. Its leaf blades range from 5 to 15 centimeters long and 0.5 to 4 millimeters wide, typically glabrous or sparsely hairy. The spikes contain 1 to 15 spikelets, with fertile florets that are generally self-pollinated.
Identification and appearance
Key characters: 1 sympatric species; readily distinguished by awnless lemmas and non-native status
Habitat and range
Habitat: Disturbed marshy sites
Elevation: < 10 m
Outside California: Washington, Oregon, Canada, native to Europe
Bloom period
Danthonia decumbens blooms Jun-Jul.
How to tell it apart
vs Avena: Danthonia glumes wrap tightly around florets; Avena glumes are shorter, leaving florets exposed.; vs Bromus: Danthonia glumes are longer than florets; Bromus glumes are shorter than florets.; vs Nassella: Danthonia has multiple florets per spikelet; Nassella has single florets with twisted awns.; vs Lolium: Danthonia spikelets have 2 prominent glumes; Lolium spikelets sit edgewise with only 1 visible glume.; vs Carex: Danthonia is a grass with open flower clusters; Carex is a sedge with flowers in dense spikes.
Frequently asked questions
Is Danthonia decumbens native to California?
No. Danthonia decumbens is not native to California (recorded as not native).
When does Danthonia decumbens bloom?
Danthonia decumbens blooms Jun-Jul.
What plant family does Danthonia decumbens belong to?
Danthonia decumbens is in the Poaceae family, genus Danthonia.
What habitat does Danthonia decumbens grow in?
Danthonia decumbens grows in Disturbed marshy sites.
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.