Malacothamnus palmeri

(S. Watson) Greene
Leafl. Bot. Observ. Crit. 1: 208. 1906.
Common names: Palmer’s or Santa Lucia bushmallow
Basionyms: Malvastrum palmeri S. Watson Proc. Amer. Acad. Arts 12: 250. 1877
Synonyms: Malacothamnus palmeri var. involucratus (B. L. Robinson) Kearney M. palmeri var. lucianus Kearney Malvastrum involucratum M. palmeri var. involucratum (B. L. Robinson) McMinn
Treatment appears in FNA Volume 6. Treatment on page 285. Mentioned on page 281.

Shrubs, 1.5–2.5 m, branches stout, indument white-canescent, grayish, or tawny, sparse to dense, stellate hairs sessile or stalked, glandular and 1–few-armed hairs sometimes also present, arms to 3 mm. Leaf blades ovate to broadly ovate, unlobed or 3- or 5-lobed, to 7–8 cm, thin or thick, surfaces: sparsely to densely grayish- to tawny-hairy, basal sinus open, not overlapping. Inflorescences terminal, headlike or, sometimes, short-spicate, flower clusters sessile, densely flowered, subtended by conspicuous bracts; stipules marginally connate, enclosing young flower clusters; involucellar bractlets distinct, sometimes basally adnate to calyx, linear to lanceolate, 8–16(–21) × 1–3(–5) mm, 2/3 –1 1/3 times calyx length. Flowers: calyx (8–)10–16(–20) mm, lobes ovate to deltate-lanceolate, 5–15 × 2.5–5.5 mm, ca. 2 times as long as wide, slightly exceeding to 4 times tube length, apex acuminate, grayish- to tawny-hairy, hairs stellate, arms to 3.5 mm and sometimes simple-glandular; petals rose-pink or pale pink to nearly white, 1.4–2(–3) cm. Mericarps 2.5–4(–5) mm. 2n = 34.

Phenology: Flowering Mar–Jul.
Habitat: Chaparral
Elevation: 30–800 m


Malacothamnus palmeri occurs in the central, outer Coast Ranges; its morphology is variable. Plants from Jolon and the Carmel Valley, Monterey County, have been called var. involucratus; they are recognized by cordate leaves, sparse indument (leaves adaxially glabrate), broad bracts to 20 mm wide subtending and partially enclosing the young flower clusters, relatively broad involucellar bractlets, calyx measurements in the lower range (to 1.5 cm), and nearly white petals 1–3 cm. They intergrade with the typical form and, in plants with short-spicate inflorescences, approach M. aboriginum. Plants from near Arroyo Seco, Monterey County, with simple and glandular hairs and generally darker rose petals have been named var. lucianus; they are otherwise similar to the typical variety.

Selected References


Lower Taxa


... more about "Malacothamnus palmeri"
David M. Bates +
(S. Watson) Greene +
Malvastrum palmeri +
Palmer’s or Santa Lucia bushmallow +
30–800 m +
Chaparral +
Flowering Mar–Jul. +
Leafl. Bot. Observ. Crit. +
Endemic +  and Illustrated +
Malacothamnus palmeri var. involucratus +, M. palmeri var. lucianus +, Malvastrum involucratum +  and M. palmeri var. involucratum +
Malacothamnus palmeri +
Malacothamnus +
species +