Malacothrix incana

(Nuttall) Torrey & A. Gray

Fl. N. Amer. 2: 486. 1843.

Common names: Dunedelion dune malacothrix
Endemic
Basionym: Malacomeris incanus Nuttall Trans. Amer. Philos. Soc., n. s. 7: 435. 1841
Synonyms: Malacothrix incana var. succulenta (Elmer) E. W. Williams Malacothrix succulenta
Treatment appears in FNA Volume 19. Treatment on page 316. Mentioned on page 311, 317.

Perennials, 12–70 cm (often mounded). Stems 1, branched proximally and distally, usually tomentose, sometimes glabrous. Cauline leaves: proximal obovate to narrowly spatulate, sometimes pinnately lobed (lobes 1–2+ pairs, subequal, apices obtuse), sometimes ± fleshy, margins usually obtuse-lobed, sometimes entire; distal not notably reduced (similar to others). Calyculi of 5–16+, ovate to lanceolate bractlets, hyaline margins 0.05–0.2 mm. Involucres 10–14 × 4–8+ mm. Phyllaries 16–30 in 2–3 series, (red-tinged) lanceolate or oblong to linear, hyaline margins 0.05–0.1 mm wide, faces glabrous. Receptacles not bristly. Florets 47–99; corollas medium yellow, 11–20 mm; outer ligules exserted 5–10 mm. Cypselae usually cylindro-fusiform, sometimes weakly prismatic, 1.5–2.2 mm, ribs extending to apices, ± equal; persistent pappi 0. Pollen 70–100% 3-porate. 2n = 14.


Phenology: Flowering Jan–Dec.
Habitat: Coastal dunes
Elevation: 0–10(–100) m

Discussion

Malacothrix incana, a dune endemic, grows currently on the coastal mainland in Santa Barbara and San Luis Obispo counties, and on San Miguel, San Nicolas, Santa Cruz, and Santa Rosa islands. Its nomenclatural type specimen was collected at San Diego, probably from the Silver Strand dune areas on Coronado Island.

Populations of a glabrous form, var. succulenta, occur in Santa Barbara County (e.g., Casmalia Beach) and San Luis Obispo County (e.g., west of Oso Flaco Lake). Glabrous forms and tomentose forms grow together on San Miguel and San Nicolas islands.

Extensive hybridization between Malacothrix incana and M. foliosa subsp. polycephala occurs on San Nicolas Island where dunes have extended into areas of normal soil, particularly along the western and southwestern portions of the island.

Hybridization between Malacothrix incana and M. saxatilis var. implicata occurs on San Miguel Island on east-facing slopes above Cuyler Harbor.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."]" is not declared as a valid unit of measurement for this property.

... more about "Malacothrix incana"
obtuse;acute or acuminate +
scarious +
ovate +  and lanceolate +
corymbiform +  and paniculiform +
indeterminate +  and determinate +
W. S. Davis +
(Nuttall) Torrey & A. Gray +
decurrent +
Malacomeris incanus +
compound +  and simple +
lanceolate;obovate oblanceolate or spatulate +
tuberculate +, rugose +, muricate +  and smooth +
ovate;lanceolate +
subequal +  and unequal +
filiform +
Dunedelion +  and dune malacothrix +
zygomorphic +, actinomorphic +  and (3-)5-merous +
1.1 cm11 mm <br />0.011 m <br /> (2 cm20 mm <br />0.02 m <br />) +
crenate +
stramineous +  and brown or purplish brown +
prismatic +  and cylindro-fusiform +
0–10(–100) m +
winged +  and beaked +
dispersed +
Coastal dunes +
indeterminate +
each +  and sessile +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
hemispheric;campanulate +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
cauline +  and basal +
obtuse-lobed +
0.05mm +  and 0.1mm +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
2-carpellate +
persistent +
Flowering Jan–Dec. +
connate +  and distinct +
16 +  and 30 +
subequal +  and unequal +
Fl. N. Amer. +
flat;more or less convex +
crenate +
exalbuminous +
glabrous +  and tomentose +
appendaged +  and truncate +
papillate +
Malacothrix incana var. succulenta +  and Malacothrix succulenta +
Malacothrix incana +
Malacothrix +
species +
70 cm700 mm <br />0.7 m <br /> (200 cm2,000 mm <br />2 m <br />) +
12 cm120 mm <br />0.12 m <br /> (70 cm700 mm <br />0.7 m <br />) +
shrub +  and subshrub +