Isoetes echinospora
Spiny spored quillwort
(c) Timothy McNitt, some rights reserved (CC BY), uploaded by Timothy McNitt · licence
Family: Isoetaceae · Type: Perennial · Native
Isoetes echinospora (Spiny spored quillwort) is a native California perennial in the Isoetaceae family, recognized by habitat (persistent water), high elevation, soft flexible evergreen leaves.
Spiny spored quillwort is a California native perennial found in the northern Sierra Nevada Mountains and Klamath Ranges in persistent lakes and pools at elevations above 1,500 meters. This aquatic plant remains submerged, producing bright green, soft, and flexible leaves less than 20 centimeters long with white to brownish bases that taper to delicate tips. Growing completely underwater, the quillwort develops distinctive sporangia with membranes covering less than half their surface and features remarkably different male and female spores. Its female spores are particularly notable, measuring 0.4 to 0.5 millimeters and covered with tiny prickles that give the species its distinctive name. The plant maintains a perennial presence in its aquatic habitat, with leaves that remain almost evergreen throughout its growing cycle.
Identification and appearance
Key characters: 5 sympatric species - key features are habitat (persistent water), high elevation, soft flexible evergreen leaves
Habitat and range
Habitat: Persistent lakes, pools
Elevation: > 1500 m
Outside California: to Alaska, eastern North America, Eurasia
How to tell it apart
vs Juncus: Isoetes has a bulbous corm-like base with embedded spore capsules; Juncus has fibrous roots without sporangia.; vs Subularia: Isoetes leaves arise from a bulbous base; Subularia has a thin taproot with small white flowers above the leaves.; vs Triglochin: Isoetes has spore capsules at leaf bases; Triglochin produces tall flower spikes with tiny greenish flowers.; vs Sparganium: Isoetes forms tight tufts from a corm; Sparganium has creeping stems and round, burr-like flower heads.; vs Pilularia: Isoetes leaves stand rigidly erect; Pilularia leaves coil in fiddlehead fashion when young.
Frequently asked questions
Is Isoetes echinospora native to California?
Yes. Isoetes echinospora is native to California (recorded as native).
What plant family does Isoetes echinospora belong to?
Isoetes echinospora is in the Isoetaceae family, genus Isoetes.
What habitat does Isoetes echinospora grow in?
Isoetes echinospora grows in Persistent lakes, pools.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.