Page authors: Don Knoke, David Giblin
Crassula aquatica
wrinkle-seed pygmyweed, water pygmy weed

Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, and in the southeastern and northeastern regions of North America.

Habitat: Mud flats and vernal pools.

Flowers: April-August

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern


Weak, glabrous annual with prostrate and nodally rooting to ascending to erect, freely-branching stems 2-6 cm. long.


Leaves opposite, entire, succulent, linear or linear-oblanceolate, 3-6 mm. long, with sheathing bases.


Flowers minute, single in the leaf axils, greenish, the pedicles short in flower but lengthening up to 6 mm. in fruit; calyx cup-shaped, 0.5-1 mm. long, with 4 ovate-triangular lobes about half the length; petals 4, membranous, whitish, oblong-lanceolate, 1.5 mm. long; stamens 4, shorter than the petals.


Follicles less than 2 mm. long, erect, purplish.

Accepted Name:
Crassula aquatica (L.) Schönland
Publication: Nat. Pflanzenfam. 51[III,2a]: 37. 1890.

Synonyms & Misapplications:
Crassula saginoides (Maxim.) M. Bywater & Wickens [KZ99]
Crassula vaillantii (Willd.) Roth., misapplied
Hydrophila vaillantii House
Tillaea angustifolia Nutt. var. bolanderi S. Watson
Tillaea aquatica L. [HC]
Tillaea bolanderi (S. Watson) Greene
Tillaea drummondii Torr. & A. Gray var. bolanderi (S. Watson) Jeps.
Tillaea vaillantii A. Gray, invalid name
Tillaeastrum pringlei Rose
Additional Resources:

PNW Herbaria: Specimen records of Crassula aquatica in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Crassula aquatica checklist entry

OregonFlora: Crassula aquatica information

E-Flora BC: Crassula aquatica atlas page

CalPhotos: Crassula aquatica photos

18 photographs:
Group by