Calycadenia micrantha
Small-flowered calycadenia
(c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Calycadenia micrantha (Small-flowered calycadenia) is a native California herb in the Asteraceae family, recognized by . Key features: slender purple-tinged stems, very small yellow rays 2-2.5mm, disk pappus absent.
Small-flowered calycadenia is a rare (CNPS 1B.2) California native annual found in northern Coast Ranges and south-central Coast Ranges on dry, open rocky ridges, hillsides, and woodland openings at elevations of 500 to 1,500 meters. Flowering from June to October, this plant produces delicate yellow flowers with one to three ray flowers, each flower approximately 2 to 2.5 millimeters long. Growing with slender purple-tinted stems 10 to 50 centimeters tall, the plant is much-branched from near mid-stem and has a delicate, multi-branched structure. Its proximal leaves range 2 to 5 centimeters long, with lance-shaped leaf structures that become more sparse and linear toward the stem tips. The fruit is characterized by rough-wrinkled ray fruits that remain glabrous, creating a distinctive seed-bearing structure.
Identification and appearance
Key characters: 4 sympatric species. Key features: slender purple-tinged stems, very small yellow rays 2-2.5mm, disk pappus absent
Habitat and range
Habitat: Dry, open rocky ridges, hillsides, talus; openings in scrub, woodland
Elevation: 500-1500 m
Bloom period
Calycadenia micrantha blooms Jun-Oct.
Conservation status
CNPS 1B.2
How to tell it apart
vs Hemizonia: Calycadenia rays deeply fringed; Hemizonia rays shallowly lobed with ray fruits beaked.; vs Osmadenia: Calycadenia covered with tack glands; Osmadenia completely lacks sticky glands.; vs Deinandra: Calycadenia rays deeply split; Deinandra rays shallowly lobed or entire.; vs Madia: Calycadenia has tack glands and deeply split rays; Madia lacks tack glands, different ray shape.; vs Holocarpha: Calycadenia has tack glands (not pit glands); Holocarpha has pit-gland depressions on bracts.
Frequently asked questions
Is Calycadenia micrantha native to California?
Yes. Calycadenia micrantha is native to California (recorded as native).
When does Calycadenia micrantha bloom?
Calycadenia micrantha blooms Jun-Oct.
What plant family does Calycadenia micrantha belong to?
Calycadenia micrantha is in the Asteraceae family, genus Calycadenia.
Is Calycadenia micrantha rare or endangered?
Calycadenia micrantha carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Calycadenia micrantha grow in?
Calycadenia micrantha grows in Dry, open rocky ridges, hillsides, talus; openings in scrub, woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.