Wolffia brasiliensis
Brazilian watermeal
(c) Asher P Higgins, some rights reserved (CC BY) · licence
Family: Araceae · Type: Herb · Native
Conservation status: CNPS 2B.3
Wolffia brasiliensis (Brazilian watermeal) is a native California herb in the Araceae family, recognized by clearly distinguished by conical bump on upper surface.
Brazilian watermeal is a rare (CNPS 2B.3) native perennial found in the Sacramento River Valley and San Francisco Bay bioregions in ponds at elevations below 100 meters. Flowering from late spring to early fall, this tiny aquatic plant produces nearly imperceptible flowers amid its dark green floating body. Growing less than 1.2 millimeters long, it forms a flat, translucent surface with a slight central elevation that allows it to drift above the water. Its minuscule body features 50 to 100 stomates and maintains a round tip, creating a unique compact form that blends seamlessly with pond surfaces. When dried, the plant's body transforms to reveal brown cellular structures, highlighting its delicate and ephemeral nature.
Identification and appearance
Key characters: 1 sympatric species; clearly distinguished by conical bump on upper surface
Habitat and range
Habitat: Ponds
Elevation: < 100 m
Outside California: to eastern United States, South America
Bloom period
Wolffia brasiliensis blooms Late spring-early fall.
Conservation status
CNPS 2B.3
How to tell it apart
vs Lemna: Wolffia is spherical and 0.4-1.3 mm; Lemna is disc-shaped, larger, and has a root.; vs Landoltia: Wolffia is spherical, rootless, and 0.4-1.3 mm; Landoltia has 2-7 roots and is much larger.; vs Spirodela: Wolffia is spherical, rootless, and 0.4-1.3 mm; Spirodela has 7-16 roots and is much larger.; vs Wolffiella: Wolffia is spherical like caviar; Wolffiella is flat and ribbon-shaped.
Frequently asked questions
Is Wolffia brasiliensis native to California?
Yes. Wolffia brasiliensis is native to California (recorded as native).
When does Wolffia brasiliensis bloom?
Wolffia brasiliensis blooms Late spring-early fall.
What plant family does Wolffia brasiliensis belong to?
Wolffia brasiliensis is in the Araceae family, genus Wolffia.
Is Wolffia brasiliensis rare or endangered?
Wolffia brasiliensis carries California Rare Plant Rank 2B.3, state rank S2.
What habitat does Wolffia brasiliensis grow in?
Wolffia brasiliensis grows in Ponds.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
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.