Chorizanthe robusta var. hartwegii
Scotts valley spineflower, Scotts Valley Spineflower
Photo: parent species Chorizanthe robusta · (c) Adam J. Searcy, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Herb · Native
Conservation status: CNPS 1B.1 · Endangered
Chorizanthe robusta var. hartwegii (Scotts valley spineflower) is a native California herb in the Polygonaceae family, recognized by erect habit and rose-pink margins.
Scotts valley spineflower is a rare (CNPS 1B.1) California native perennial found in southern San Francisco Bay Region in Scotts Valley, Santa Cruz County, growing in sandy habitats at elevations of 200 to 300 meters. Flowering from April to July, this plant produces delicate flowers with rose-pink lobe margins. Growing erect with stems 5 to 30 centimeters tall, it develops a compact and slender form. Its leaves are narrow and relatively small, with blades 1.5 to 5 centimeters long and 0.2 to 0.5 centimeters wide. The plant's distinctive involucre measures 2.5 to 3.5 millimeters, featuring subtle rose-pink edges that highlight its delicate structure.
Identification and appearance
Key characters: 10 sympatric species; diagnostic erect habit and rose-pink margins
Habitat and range
Habitat: Sand
Elevation: 200-300 m
Bloom period
Chorizanthe robusta var. hartwegii blooms Apr-Jul.
Conservation status
CNPS 1B.1 · Endangered
How to tell it apart
vs Eriogonum: Chorizanthe has 1 flower per involucre; Eriogonum has multiple flowers per involucre.; vs Eremothera: Chorizanthe has 6-parted flowers in spiny cups; Eremothera has 4-petaled evening-primrose flowers.; vs Calyptridium: Chorizanthe has flowers in awned involucres; Calyptridium has naked flowers with papery sepals.; vs Lastarriaea: Chorizanthe has thin papery flowers; Lastarriaea has distinctly thick, leathery-textured flowers.; vs Navarretia: Chorizanthe is in Polygonaceae with 6-parted flowers; Navarretia is in Polemoniaceae with 5-lobed tubular flowers.
Frequently asked questions
Is Chorizanthe robusta var. hartwegii native to California?
Yes. Chorizanthe robusta var. hartwegii is native to California (recorded as native).
When does Chorizanthe robusta var. hartwegii bloom?
Chorizanthe robusta var. hartwegii blooms Apr-Jul.
What plant family does Chorizanthe robusta var. hartwegii belong to?
Chorizanthe robusta var. hartwegii is in the Polygonaceae family, genus Chorizanthe.
Is Chorizanthe robusta var. hartwegii rare or endangered?
Chorizanthe robusta var. hartwegii carries California Rare Plant Rank 1B.1, state rank S1.
What habitat does Chorizanthe robusta var. hartwegii grow in?
Chorizanthe robusta var. hartwegii grows in Sand.
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.