Taxon Report

Panicum acuminatum Sw. var. thermale (Bol.) Wipff

Geysers panicum

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Taxon Summary

Panicum acuminatum var. thermale, commonly known as Geysers panicum, is a annual/perennial herb in the Poaceae that is found only in California. It occurs within Closed-cone coniferous forest, Riparian forest, and Valley and foothill grassland, growing at elevations from 305 to 2470 meters. Panicum acuminatum var. thermale is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Panicum acuminatum Sw. var. thermale (Bol.) Wipff
Common Name:	Geysers panicum
Family:	Poaceae
Element Code:	PMPOA24028
USDA Plants Symbol:
Synonyms/Other Names:	Panicum thermale Boland. Dichanthelium lanuginosum var. thermale

Ecology and Life History


Lifeform:	annual/perennial herb
Blooming Period: Jun-Aug	Jun-Aug
Elevation:	305-2470 (1000-8105)
General Habitats:	Closed-cone coniferous forest, Riparian forest, Valley and foothill grassland
Microhabitat:	Streambanks (sometimes)
Microhabitat Details:	geothermally-altered soil

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G5T2Q
State Rank:	S2
State List:	CE
Fed List:	None
Other Status:	BLM_S; SB_UCSC
CRPR Changes:	changed from 1B.1 to 1B.2 on 2012-09-12

Occurrence Data from the CNDDB


Total Occurrences:	11
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	3
Fair (C)	0
Poor (D)	0
None (X)	1
Unknown (U)	6

Location


California Endemic: True
California Counties and Islands: Name (Code)
Lake (LAK), Plumas (PLU), Shasta (SHA), Sonoma (SON), Tehama (TEH)
Quads: Name (Quad Code)
Lassen Peak (4012145), Reading Peak (4012144), The Geysers (3812277), Whispering Pines (3812276)

Threat List Data from the CNDDB


Threat List Total:	7
EOs with Threat Listed:	Total EOs	% of EOs
	4	36 %
Mining	4	36%
Development	4	36%
Erosion/runoff	4	36%
Non-native plant impacts	3	27%
Other	2	18%
Road/trail construction/maint.	1	9%
Feral pigs	1	9%

Notes



Known only from The Geysers and Lassen Volcanic NP geothermal areas. Does plant occur on Mt. Shasta (SIS Co.)? Plants from Blaney Meadows (FRE Co.) need verification. Threatened by non-native plants. A synonym of Panicum acuminatum var. acuminatum in TJM (1993). See Proceedings of the California Academy of Sciences 2:181 (1862) for original description, Madroño 23(3):151 (1975) for taxonomic treatment, and Proceedings of the CNPS Conservation Conference, pp. 256-263 (2009) for information on population dynamics and monitoring.
Threats:

Taxonomy:

Selected References

CRPR List Change on 2012-09-12

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 2 November 2025].