Malacothamnus astrotentaculatus
Starry-tentacled bushmallow
(c) Trevor Van Loon, some rights reserved (CC BY), uploaded by Trevor Van Loon · licence
Family: Malvaceae · Type: Shrub · Native
Conservation status: CNPS 1B.3
Malacothamnus astrotentaculatus (Starry-tentacled bushmallow) is a native California shrub in the Malvaceae family, recognized by distinctive calyx vein outgrowths.
Starry-tentacled bushmallow is a rare (CNPS 1B.3) California native shrub found in early-recovering post-burn woody vegetation at elevations of 400 to 1,070 meters. Flowering from May to August, this plant produces pale to bright pink flowers in dense, interrupted spikes with distinctive linear bracts. Growing as a compact shrub up to 1.25 meters tall with densely stellate-hairy stems, its appearance is notably characterized by its ashy to bright-green leaves. Its leaf blades are roughly round to widely ovate, with 3 to 7 rounded or acute lobes and a heart-shaped base, covered in stellate hairs that are more dense on the leaf undersides. The plant's unique calyx features thread-like outgrowths and stellate hairs, giving it a distinctive textural appearance in its native habitat.
Identification and appearance
Key characters: Geographically isolated; distinctive calyx vein outgrowths
Habitat and range
Habitat: Early-recovering post-burn woody vegetation, edges of openings, some plants occasionally persisting into more mature vegetation stages
Elevation: 400-1070 m
Bloom period
Malacothamnus astrotentaculatus blooms May-Jul(Aug).
Conservation status
CNPS 1B.3
How to tell it apart
vs Sphaeralcea: Malacothamnus has flowers clustered in leaf axils; Sphaeralcea has flowers in an elongated spike-like arrangement.; vs Sidalcea: Malacothamnus is a woody shrub in chaparral; Sidalcea is herbaceous in meadows and moist areas.; vs Malva: Malacothamnus is a native chaparral shrub with axillary clusters; Malva is a weedy herb with flowers along stems.; vs Ribes: Malacothamnus has mallow flowers with fused stamens; Ribes has tubular flowers and produces berries.; vs Brickellia: Malacothamnus has 5-petaled mallow flowers; Brickellia has fuzzy composite flower heads without petals.
Frequently asked questions
Is Malacothamnus astrotentaculatus native to California?
Yes. Malacothamnus astrotentaculatus is native to California (recorded as native).
When does Malacothamnus astrotentaculatus bloom?
Malacothamnus astrotentaculatus blooms May-Jul(Aug).
What plant family does Malacothamnus astrotentaculatus belong to?
Malacothamnus astrotentaculatus is in the Malvaceae family, genus Malacothamnus.
Is Malacothamnus astrotentaculatus rare or endangered?
Malacothamnus astrotentaculatus carries California Rare Plant Rank 1B.3, state rank S2.
What habitat does Malacothamnus astrotentaculatus grow in?
Malacothamnus astrotentaculatus grows in Early-recovering post-burn woody vegetation, edges of openings, some plants occasionally persisting into more mature vegetation stages.
Related species
Other California species in the same genus, family, or bioregion.
- Malacothamnus clementinus — San clemente island bushmallow
- Malacothamnus davidsonii — Tujunga bushmallow
- Malacothamnus densiflorus — Many-flowered bush mallow
- Malacothamnus densiflorus var. densiflorus — Few-rayed bushmallow
- Malacothamnus densiflorus var. viscidus — Emerald unicorn bushmallow
- Malacothamnus discombobulatus — Discombobulating bushmallow
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
Last updated 2026-09-15
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.