Myriophyllum hippuroides

Western water-milfoil, Western Water-Milfoil

Family: Haloragaceae · Type: perennial · Native

Western water-milfoil is a California native perennial found in northern Coast Ranges, northern Coast Range Interior, northern Sierra Nevada, San Joaquin Valley, northern Central Coast, and San Francisco Bay Area in ponds and small streams at elevations below 1,100 meters. Flowering from July to September, this aquatic plant produces small, inconspicuous flowers in emergent spikes 3 to 12 centimeters long. Growing to over 1 meter in length with branching underwater stems, it forms dense underwater vegetation. Its leaves are arranged in whorls of 4 to 5 with scattered single leaves, with submerged leaves having fine, linear segments typically 14 to 20 per leaf, each segment less than 10 millimeters long. The plant's delicate, finely divided leaves create intricate underwater structures that provide habitat for aquatic organisms.

Habitat: Ponds, small streams

Bloom period: Jul-Sep

Elevation: < 1100 m

Bioregions: NCoRO, NCoRI, n SNH, SnJV, n CCo, SnFrB

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.