Myriophyllum verticillatum
Whorled water-milfoil, Whorled Water-Milfoil
(c) Panek, some rights reserved (CC BY-SA) · licence
Family: Haloragaceae · Type: Herb · Native
Myriophyllum verticillatum (Whorled water-milfoil) is a native California herb in the Haloragaceae family, recognized by club-shaped winter buds and dissected bracts.
Whorled water-milfoil is a California native perennial found in northern Coast Ranges, northern and central Sierra Nevada, and Great Basin regions in lakes and marshes at elevations up to 2,072 meters. Flowering from July to September, this aquatic plant produces small, delicate flowers arranged in emergent spikes 5 to 12 centimeters long. Growing with dark green to nearly black stems over 1 meter tall, it develops distinctive winter buds shaped like clubs at the ends of non-flowering branches. Its submersed leaves are intricately divided, with 18 to 34 fine linear segments less than 10 millimeters long, creating a feathery underwater appearance. The plant forms distinctive monoecious structures, with male and female flowers on the same plant.
Identification and appearance
Key characters: 3 sympatric species; club-shaped winter buds and dissected bracts are diagnostic
Habitat and range
Habitat: Lakes, marshes
Elevation: < 2072 m
Outside California: to Alaska, Canada, eastern United States, Eurasia
Bloom period
Myriophyllum verticillatum blooms Jul-Sep.
How to tell it apart
vs Hippuris: Myriophyllum has feathery divided leaves; Hippuris has simple, undivided linear leaves in whorls.; vs Elodea: Myriophyllum has leaves pinnately divided into thread-like segments; Elodea has simple oval leaves.; vs Ceratophyllum: Myriophyllum leaves fork from a central spine; Ceratophyllum leaves fork repeatedly without central axis.; vs Ranunculus: Myriophyllum has whorled feathery leaves; aquatic Ranunculus has alternate or basal divided leaves.; vs Potamogeton: Myriophyllum has feathery divided leaves; Potamogeton has simple, entire leaves (blade-like or oval).
Frequently asked questions
Is Myriophyllum verticillatum native to California?
Yes. Myriophyllum verticillatum is native to California (recorded as native).
When does Myriophyllum verticillatum bloom?
Myriophyllum verticillatum blooms Jul-Sep.
What plant family does Myriophyllum verticillatum belong to?
Myriophyllum verticillatum is in the Haloragaceae family, genus Myriophyllum.
What habitat does Myriophyllum verticillatum grow in?
Myriophyllum verticillatum grows in Lakes, marshes.
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.