Panicum acuminatum var. thermale
Geysers panicum
Photo: parent species Panicum acuminatum · (c) aarongunnar, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 1B.2
Panicum acuminatum var. thermale (Geysers panicum) is a native California grass in the Poaceae family, recognized by habitat at hot springs and fumaroles is distinctive.
Geysers panicum is a rare (CNPS 1B.2) California native perennial found in northern Coast Ranges and High Cascade Range regions in peaty meadows and hot spring areas at elevations of 500 to 2,700 meters. Flowering from June to September, this plant produces delicate, small spikelet flowers approximately 2 millimeters long in subtle inflorescences. Growing with stems 10 to 80 centimeters tall, it develops soft, spreading vegetation characteristic of thermal meadow environments. Its leaves are distinctive, with soft-hairy blades 4 to 10 centimeters long and 5 to 12 millimeters wide, featuring a notably soft, downy texture on the underside. The plant's unique adaptation to hot spring and fumarole environments makes it a specialized meadow grass with remarkable thermal tolerance.
Identification and appearance
Key characters: 6 sympatric species; habitat at hot springs and fumaroles is distinctive
Habitat and range
Habitat: Peaty meadows and pockets, often at hot springs and fumaroles
Elevation: 500-2700 m
Bloom period
Panicum acuminatum var. thermale blooms Jun-Sep.
Conservation status
CNPS 1B.2
How to tell it apart
vs Deschampsia: Panicum has thick rigid lemmas and well-developed lower glumes; hairgrass has thin awned florets and tiny glumes.; vs Dichanthelium: Panicum has a single flowering period; rosette grass produces two distinct flower types (spring and summer).; vs Hilaria: Panicum has single spikelets on branches; curly mesquite has spikelets in clusters of three along a spike.; vs Sorghum: Panicum has single spikelets throughout panicle; sorghum has three-spikelet groups at branch tips.; vs Echinochloa: Panicum has a membranous ligule and panicle; barnyard grass lacks a ligule and has bristly branches.
Frequently asked questions
Is Panicum acuminatum var. thermale native to California?
Yes. Panicum acuminatum var. thermale is native to California (recorded as native).
When does Panicum acuminatum var. thermale bloom?
Panicum acuminatum var. thermale blooms Jun-Sep.
What plant family does Panicum acuminatum var. thermale belong to?
Panicum acuminatum var. thermale is in the Poaceae family, genus Panicum.
Is Panicum acuminatum var. thermale rare or endangered?
Panicum acuminatum var. thermale carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Panicum acuminatum var. thermale grow in?
Panicum acuminatum var. thermale grows in Peaty meadows and pockets, often at hot springs and fumaroles.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.