Page author: David Giblin
Ceratocephala testiculata
hornseed buttercup

Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Great Plains.

Habitat: Disturbed soil in sagebrush deserts and plains.

Flowers: March-May

Origin: Introduced from Europe

Growth Duration: Annual

Conservation Status: Not of concern


Small, scapose annual, finely white-woolly throughout.


Leaves all basal, 1.5-4 cm. long, ternate to bi-ternate, the segments linear, about equal in width to the petioles.


Peduncles leafless, 2-8 cm. tall, the flowers solitary; sepals 5, greenish, ovate-lanceolate, 4-6 mm. long; petals 5, pale yellow, narrow, 5-8 mm. long; nectary scale oblong-elliptic, 1 mm. long, the lateral margins free to the base; receptacle linear, glabrous; stamens 10-15; achenes 35-70, spreading.


Achene with 2 bulges on the base, then narrowed to a straight beak 3-4 mm. long.

Accepted Name:
Ceratocephala testiculata (Crantz) Besser
Publication: Enum. Pl. [Besser] 70. 1822.

Synonyms & Misapplications:
Ceratocephalus orthoceras DC.
Ranunculus testiculatus Crantz [FNA3, HC]
Additional Resources:

PNW Herbaria: Specimen records of Ceratocephala testiculata in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Ceratocephala testiculata checklist entry.

OregonFlora: Ceratocephala testiculata information.

E-Flora BC: Ceratocephala testiculata atlas page.

CalPhotos: Ceratocephala testiculata photos.

USDA Plants: Ceratocephala testiculata information.

43 photographs:
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