Nemacaulis denudata var. gracilis
Slender cottonheads, Slender Cottonheads
Photo: parent species Nemacaulis denudata · (c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Herb · Native
Conservation status: CNPS 2B.2
Nemacaulis denudata var. gracilis (Slender cottonheads) is a native California herb in the Polygonaceae family, recognized by One sympatric species; clear habitat and morphological differences.
Slender cottonheads is a rare (CNPS 2B.2) California native annual found in southwestern and desert southern California bioregions in desert habitats at elevations of 10 to 500 meters. Flowering from January to May, this plant produces white flowers obscured by light brown hairs, creating delicate woolly flower clusters. Growing with slender stems 4 to 25 centimeters tall and spreading up to 20 centimeters wide, it forms a delicate, open structure in arid landscapes. Its leaves are narrow and elongated, measuring 1 to 7 centimeters long and only 1 to 6 millimeters wide, contributing to its graceful, minimalist appearance. The plant's involucre bracts are small, measuring 2 to 4 millimeters long and approximately 0.5 to 1 millimeter wide.
Identification and appearance
Key characters: One sympatric species; clear habitat and morphological differences
Habitat and range
Habitat: Deserts
Elevation: 10-500 m
California counties: San Diego, San Bernardino, Imperial, Riverside, Los Angeles, Fresno
Outside California: Arizona, northwestern Mexico
Bloom period
Nemacaulis denudata var. gracilis blooms Jan-May.
Conservation status
CNPS 2B.2
How to tell it apart
vs Lastarriaea: Nemacaulis has many spine-less bracts creating cottony heads; Lastarriaea has only 3 spine-tipped bracts.; vs Hollisteria: Nemacaulis has many spine-less bracts; Hollisteria has 3-4 spine-tipped bracts.; vs Johanneshowellia: Nemacaulis has many bracts creating cottony flower heads; Johanneshowellia has 4-7 bracts without the cottony appearance.
Frequently asked questions
Is Nemacaulis denudata var. gracilis native to California?
Yes. Nemacaulis denudata var. gracilis is native to California (recorded as native).
When does Nemacaulis denudata var. gracilis bloom?
Nemacaulis denudata var. gracilis blooms Jan-May.
Where in California does Nemacaulis denudata var. gracilis grow?
Nemacaulis denudata var. gracilis occurs in San Diego, San Bernardino, Imperial, Riverside, Los Angeles, Fresno, at elevations of 10-500 m.
What plant family does Nemacaulis denudata var. gracilis belong to?
Nemacaulis denudata var. gracilis is in the Polygonaceae family, genus Nemacaulis.
Is Nemacaulis denudata var. gracilis rare or endangered?
Nemacaulis denudata var. gracilis carries California Rare Plant Rank 2B.2, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · 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.