Myosurus apetalus var. borealis
Bristly mousetail
(c) Tim Messick, some rights reserved (CC BY), uploaded by Tim Messick · licence
Family: Ranunculaceae · Type: Herb · Native
Myosurus apetalus var. borealis (Bristly mousetail) is a native California herb in the Ranunculaceae family, recognized by sepal venation and aggregate length.
Bristly mousetail is a native annual herb found in the northern California Ranges and Modoc Plateau in sagebrush habitats and marshy flats at elevations of 600 to 1,500 meters. Flowering in May, this delicate plant produces tiny flowers with wide scarious-margined sepals that are uniquely single-veined. Growing with slender, sparse stems typically less than 15 centimeters tall, it forms a low, sparse botanical profile across open landscapes. Its leaves are narrow and grass-like, emerging from the base of the plant in small, understated clusters. The fruit develops as a compact aggregate 4 to 9 millimeters long, with outer surfaces that are narrowly elliptic or rectangular.
Identification and appearance
Key characters: 2 sympatric species; distinguished by sepal venation and aggregate length
Habitat and range
Habitat: Flats, marshes, generally sagebrush
Elevation: 600-1500 m
Outside California: to British Columbia, Wyoming
Bloom period
Myosurus apetalus var. borealis blooms May.
How to tell it apart
vs Triglochin: Myosurus has distinctive elongated cone-shaped fruiting heads; Triglochin has slender spikes of scale-like flowers.; vs Typha: Myosurus is a tiny annual inches tall; Typha is a robust perennial several feet tall with brown flower heads.; vs Sparganium: Myosurus has cone-shaped receptacles on single stems; Sparganium has round, burr-like heads in branched clusters.; vs Juncus: Myosurus is an annual with elongated fruiting cones; Juncus is perennial with round capsules in branched clusters.
Frequently asked questions
Is Myosurus apetalus var. borealis native to California?
Yes. Myosurus apetalus var. borealis is native to California (recorded as native).
When does Myosurus apetalus var. borealis bloom?
Myosurus apetalus var. borealis blooms May.
What plant family does Myosurus apetalus var. borealis belong to?
Myosurus apetalus var. borealis is in the Ranunculaceae family, genus Myosurus.
What habitat does Myosurus apetalus var. borealis grow in?
Myosurus apetalus var. borealis grows in Flats, marshes, generally sagebrush.
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.