Page author: Don Knoke
Cyclachaena xanthiifolia
carelessweed, burweed marsh elder, tall marsh elder
WTU specimens
Other herbaria

Distribution: Eastern Washington south to New Mexico, east to Alberta and Texas.

Habitat: Bottom land and moist waste places.

Flowers: August - October

Origin: Introduced?

Conservation Status: Not of concern

Description:
General:

Large, coarse annual up to 20 dm. tall.

Leaves:

Leaves long-petiolate, the blade broadly ovate, 5-20 cm. long and 2.5-20 cm. wide, coarsely and often doubly serrate, gradually reduced upward.

Flowers:

Heads numerous, nearly sessile, in a large, paniculiform inflorescence; involucre 1.5-3 mm. high, the 5 herbaceous outer bracts larger than the 5 membranous inner bracts; corollas of the pistillate flowers obsolete; staminate corollas tubular, greenish, with undivided style, the filaments attached to each other; receptacle small, chaffy throughout; pappus none.

Fruits:

Achenes compressed parallel to the involucral bracts.

Accepted Name:
Cyclachaena xanthiifolia (Nutt.) Fresenius
Publication: Index Seminum (Frankfurt). 1836: 4. 1836. 1836.

Synonyms & Misapplications:
Iva xanthifolia Nutt. [HC]
Iva xanthiifolia Nutt.
Additional Resources:

PNW Herbaria: Specimen records of Cyclachaena xanthiifolia in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Cyclachaena xanthiifolia checklist entry.

E-Flora BC: Cyclachaena xanthiifolia atlas page.

CalPhotos: Cyclachaena xanthiifolia photos.

USDA Plants: Cyclachaena xanthiifolia information.

16 photographs:
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