Species Details

Calamagrostis crassiglumis

Thurber's reed grass

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Scientific Name:
Calamagrostis crassiglumis Thurb.
Common Name:
Thurber's reed grass
Family: Poaceae
Element Code: PMPOA17070
USDA Plants Symbol:
Synonyms/Other Names:
CA Rare Plant Rank: 2B.1
Fed List: None
State List: None
Global Rank: G3Q
State Rank:
Other Status:
CRPR Changes:
changed from 2.1 to 2B.1 on 2013-09-13
removed from 2.1 on 2013-02-01
Add Date: 1980-01-01
Date Edited: 2022-09-06
Lifeform: perennial rhizomatous herb
Blooming Period: May-Aug
10 - 60 meters
35 - 195 feet
General Habitat:
  • Coastal scrub (mesic)
  • Marshes and swamps (freshwater)
General Micro Habitat:
Micro Habitat:
Threatened by grazing at Pt. Reyes NS.
A synonym of C. stricta ssp. inexpansa in TJM (1993) and TJM 2; distinguished from this taxon in glume texture and shape: C. crassiglumis has thickened glumes that are rounded towards the base (vs. membranous, not thickened glumes that are keeled towards the base), generally shorter ligules (1-3 mm long vs. 2-5.5(6) mm long), and generally shorter panicles (3-8 cm long vs. (5)8-15 cm long in C. stricta ssp. inexpansa).
Total Occurrences: 15
Element Occurrence Ranks:
1 2 2 0 0 10
Occurrence Status:
Historical >20 Years 15
Recent <=20 Years 0
Presumed Extant 15
Possibly Extirpated 0
Presumed Extirpated 0
California Endemic:
California Island:
States: Name (Code)
Arizona (AZ), California (CA), Colorado (CO), Idaho (ID), Nevada (NV), New Mexico (NM), Oregon (OR), Utah (UT), Washington (WA), Wyoming (WY)
California Counties and Islands: Name (Code)
Del Norte (DNT), Humboldt (HUM), Marin (MRN), Mendocino (MEN), Sonoma (SON)
Quads: Name (Quad Code)
Ah Pah Ridge (4112348), Bodega Head (3812331), Crescent City (4112472), Drakes Bay (3812218), Fern Canyon (4112441), High Divide (4112481), High Plateau Mtn. (4112388), Holter Ridge (4112338), Inglenook (3912357), Mendocino (3912337), Orick (4112431), San Rafael (3712285), Sebastopol (3812247), Sister Rocks (4112462)
Definitions of codes following a county and/or quad:
* Presumed extirpated
(?) Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.


Presumed Extant
Counties   Quads