Malacothamnus densiflorus

(S. Watson) Greene

Leafl. Bot. Observ. Crit. 1: 208. 1906.

Common names: Dense-flowered or yellowstem bushmallow
Basionyms: Malvastrum densiflorum S. Watson Proc. Amer. Acad. Arts 17: 368. 1882
Synonyms: Malacothamnus densiflorus var. viscidus (Abrams) Kearney Malvastrum densiflorum var. viscidum (Abrams) Estes M. viscidum Sphaeralcea densiflora S. densiflora var. viscida (Abrams) Jepson
Treatment appears in FNA Volume 6. Treatment on page 284. Mentioned on page 281, 282, 285.

Shrubs, 1–2 m, branches slender, indument tawny, sparse to moderately dense, stellate hairs sessile or subsessile, usually overlain by 1–2–few-armed, bristly hairs to 3 mm, glandular-hairs often abundant. Leaf-blades ovate, broadly ovate, or round, unlobed or 3-lobed or 5-lobed, 3–6 cm, often leathery, surfaces: abaxial sometimes glossy green, adaxial densely tawny-hairy, basal sinus open, not overlapping. Inflorescences interrupted, spicate, flower clusters sessile, glomerate, 10+-flowered; involucellar bractlets awl-shaped to filiform, 5–15 × 1 mm, 2/3–1 1/2 times calyx length. Flowers: calyx angled in bud, 6–14 mm, lobes triangular to ovate, 4–11 × 2.3–3.5 (–5) mm, slightly less to slightly more than 2 times as long as wide, equaling to 3 times tube length, apex acute to acuminate, sparsely bristly-hairy, hairs 1–few-armed, to 3 mm; petals pale-pink, 1–2 cm. Mericarps 2.4–3.2 mm. 2n = 34.


Phenology: Flowering Mar–Jun(Sep–Oct).
Habitat: Chaparral, coastal sage scrub ecotone
Elevation: (100–)300–1100 m

Distribution

V6 517-distribution-map.jpg

Calif., Mexico (Baja California)

Discussion

Malacothamnus densiflorus occurs in the southern Coast Ranges. Plants with relatively short involucellar bractlets and calyx measurements in the lower range have been recognized as var. viscidus; intergradation with more typical forms is complete. Malacothamnus densiflorus intergrades with M. fasciculatus at lower elevations of the coastal Peninsula Ranges in San Diego County.

Selected References

None.

Lower Taxa

None.

No values specified.No values specified.

... more about "Malacothamnus densiflorus"
loculicidal +
bristly-hairy +
David M. Bates +
(S. Watson) Greene +
not overlapping +
cordate +  and truncate or cuneate +
Malvastrum densiflorum +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
5-lobed;3-lobed;unlobed;round;ovate;5-lobed;3-lobed;unlobed;round;ovate;5-lobed;3-lobed;unlobed;round;ovate;ovate +
ovate +  and round rhombic or reniform unlobed or palmately 3-lobed 5-lobed or 7-lobed +
awl-shaped +  and filiform +
1 cm10 mm <br />0.01 m <br /> (?) +
slender +
not accrescent +
0.6 cm6 mm <br />0.006 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
indehiscent +  and loculicidal +
Dense-flowered or yellowstem bushmallow +
white +, usually rose +  and pale-pink pinkish mauve or mauve +
Calif. +  and Mexico (Baja California) +
(100–)300–1100 m +
sparse;copious +
subterminal +
10+-flowered +, glomerate +  and sessile +
unisexual +  and bisexual +
subglobose-obovate +, disclike +  and not inflated +
Chaparral, coastal sage scrub ecotone +
1-few-armed +, 1-2-few-armed +, subsessile +  and sessile +
bifurcate +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
spicate +  and interrupted +
tough-fibrous +
connate +  and distinct +
simple +, stipulate +, sessile +, subsessile +  and petiolate +
distichous +  and alternate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
triangular +  and ovate +
less;wide +
entire +  and serrate +
smooth-walled +  and 1-celled +
asymmetrically suborbicular +  and obovoid-reniform +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
7-14-carpellate +
adnate +  and distinct +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Flowering Mar–Jun(Sep–Oct). +
Leafl. Bot. Observ. Crit. +
minutely stellate-hairy or rarely glabrous +  and papillate-stellate +
Black (?) +  and Brown (?) +
hairy +  and glabrous +
obovoid-reniform +
persistent +
sessile +  and subsessile +
ascending;erect +
filiform +, linear +  and capitate +
1-2 times number of carpels +
filiform +  and subulate +
7-14-branched +
Malacothamnus densiflorus var. viscidus +, Malvastrum densiflorum var. viscidum +, M. viscidum +, Sphaeralcea densiflora +  and S. densiflora var. viscida +
Malacothamnus densiflorus +
Malacothamnus +
species +
glabrate +  and densely hairy +
monoecious +, dioecious +  and hermaphroditic +