Najas guadalupensis subsp. guadalupensis
Common water-nymph, Common Water-Nymph
Robert H. Mohlenbrock (via Wikimedia Commons) · CC0
Family: Hydrocharitaceae · Type: Herb · Native
Najas guadalupensis subsp. guadalupensis (Common water-nymph) is a native California herb in the Hydrocharitaceae family, recognized by highest leaf tooth count and smooth stems.
Common water-nymph is a California native annual found in the North Coast Ranges, Central Valley, Central Western California, southern Coastal California, and desert regions in ponds and lakes at elevations below 1,200 meters. Flowering in July, this delicate aquatic plant produces small, inconspicuous flowers with distinctive leaf margins. Growing as a slender underwater plant with transparent stems, it forms dense underwater meadows in still water environments. Its narrow leaves have remarkably fine, closely spaced marginal teeth, with 50 to 100 tiny teeth along each leaf edge, giving the plant a finely serrated appearance. As a monoecious species, the plant produces both male and female reproductive structures within the same plant, with tiny seeds less than one millimeter wide.
Identification and appearance
Key characters: 3 sympatric species; distinguished by highest leaf tooth count and smooth stems
Habitat and range
Habitat: Ponds, lakes
Elevation: < 1200 m
Outside California: to Oregon, eastern United States, South America
Bloom period
Najas guadalupensis subsp. guadalupensis blooms Jul.
How to tell it apart
vs Hydrilla: Najas leaves have obvious teeth along margins; Hydrilla has spiny bumps on the leaf midrib underneath.; vs Elodea: Najas leaves are arranged opposite or in whorls of many; Elodea has 2-3 leaves at stem base, 3-7 higher up.; vs Egeria: Najas has tiny leaves under 1.5 cm; Egeria leaves are much larger (1.2-4 cm long).; vs Ottelia: Najas is completely submerged with tiny flowers; Ottelia has floating leaves and showy white flowers above water.; vs Limnobium: Najas is fully submerged with narrow toothed leaves; Limnobium has round floating leaves on spongy stalks.
Frequently asked questions
Is Najas guadalupensis subsp. guadalupensis native to California?
Yes. Najas guadalupensis subsp. guadalupensis is native to California (recorded as native).
When does Najas guadalupensis subsp. guadalupensis bloom?
Najas guadalupensis subsp. guadalupensis blooms Jul.
What plant family does Najas guadalupensis subsp. guadalupensis belong to?
Najas guadalupensis subsp. guadalupensis is in the Hydrocharitaceae family, genus Najas.
What habitat does Najas guadalupensis subsp. guadalupensis grow in?
Najas guadalupensis subsp. guadalupensis grows in Ponds, lakes.
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.