Taxon Report

Poa napensis Beetle

Napa blue grass

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Taxon Summary

Poa napensis, commonly known as Napa blue grass, is a perennial herb in the Poaceae that is found only in California. It occurs within Meadows and seeps, and Valley and foothill grassland, growing at elevations from 100 to 200 meters. Poa napensis is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.


Ecology and Life History

Lifeform: perennial herb
Blooming Period: May-Aug May-Aug
Elevation: 100-200 (330-655)
General Habitats: Meadows and seeps, Valley and foothill grassland
Microhabitat: Alkaline
Microhabitat Details: near thermal springs

Occurrence Data from the CNDDB

Total Occurrences: 2
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 2
   Fair (C) 0
   Poor (D) 0
   None (X) 0
   Unknown (U) 0
California Endemic:  True
California Counties and Islands: Name (Code)
Napa (NAP)
Quads: Name (Quad Code)
Calistoga (3812255)

Threat List Data from the CNDDB

Threat List Total: 7
EOs with Threat Listed: Total EOs % of EOs
2 100 %
Development 2 100%
Foot traffic/trampling 2 100%
Grazing 1 50%
ORV activity 1 50%
Other 1 50%
Road/trail construction/maint. 1 50%
Surface water diversion 1 50%

Notes

Known from only two occurrences in the Calistoga area. Threatened by development, hydrological alterations, recreational activities, and airport maintenance. See Leaflets of Western Botany 4:289 (1946) for original description.
Threats:
Taxonomy:
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 31 January 2025].