Xylorhiza cognata
Mecca-aster
no rights reserved · CC0
Family: Asteraceae · Type: Shrub · Native
Conservation status: CNPS 1B.2
Xylorhiza cognata (Mecca-aster) is a native California shrub in the Asteraceae family, recognized by peduncle length and phyllary characteristics.
Mecca-aster is a rare (CNPS 1B.2) California native shrub found in the southern desert regions of Imperial and Riverside counties in arid canyons and creosote-bush scrub at elevations below 400 meters. Flowering from January to July, this plant produces lavender or light blue ray flowers with 20 to 30 rays extending 1.8 to 2.5 centimeters long. Growing as a compact shrub up to 1.5 meters tall with branches spread throughout and generally short-glandular stems, it develops a somewhat ill-scented structure. Its leaves range from 1 to 5 centimeters long, appearing oblanceolate to ovate with obtuse or acute tips, sometimes featuring spiny-dentate edges. The plant produces fruit 3 to 4.5 millimeters long with pappus bristles up to 9.5 millimeters in length.
Identification and appearance
Key characters: 2 sympatric species; distinguished by peduncle length and phyllary characteristics
Habitat and range
Habitat: Arid canyons, washes; creosote-bush scrub
Elevation: < 400 m
Bloom period
Xylorhiza cognata blooms Jan-Jul.
Conservation status
CNPS 1B.2
How to tell it apart
vs Erigeron: Erigeron has many thin rays in multiple rows, not fewer wide rays in one row; vs Corethrogyne: Corethrogyne has brown pappus and sterile rays; Xylorhiza has white pappus and fertile rays; vs Dieteria: Dieteria has smaller heads (under 3cm) and herbaceous stems, not woody bases; vs Trixis: Trixis has all tubular yellow flowers pointing one direction, not radial daisy heads; vs Isocoma: Isocoma lacks ray flowers entirely, having only yellow disk flowers
Frequently asked questions
Is Xylorhiza cognata native to California?
Yes. Xylorhiza cognata is native to California (recorded as native).
When does Xylorhiza cognata bloom?
Xylorhiza cognata blooms Jan-Jul.
What plant family does Xylorhiza cognata belong to?
Xylorhiza cognata is in the Asteraceae family, genus Xylorhiza.
Is Xylorhiza cognata rare or endangered?
Xylorhiza cognata carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Xylorhiza cognata grow in?
Xylorhiza cognata grows in Arid canyons, washes; creosote-bush scrub.
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.