Trichoptilium incisum (A. Gray) A. Gray
Family: Asteraceae
Yellowdome,  more...
Trichoptilium incisum image

Leaf blades 1-5 cm × 3-12 mm. Disc corollas ca. 4 mm. Cypselae ca. 3 mm; pappi 3-3.5 mm. 2n = 26.

Flowering Jan-May. Sandy or gravelly soils, deserts; 0-700 m; Ariz., Calif., Nev.; Mexico (Baja California, Baja California Sur).

FNA 2006, Jepson 2012, Kearney and Peebles 1969

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Herbaceous winter annuals, low-growing to 30 cm tall or more, stems 1-several from base, erect or ascending, diffusely branching from bases or throughout, herbage tomentose to floccose-woolly.

Leaves: Mostly alternate or sometimes opposite, oblong to lanceolate, oblanceolate, spatulate or ovate, 1-5 cm long and 3-12 mm wide with acute tips, margins usually sharply and coarsely toothed or lobed, faces sparsely floccose (flocked) to densely woolly, gland or resin-dotted, blades borne sessile or tapered to a short, winged petiole, mostly clustered in proximal (upper) half of plant.

Flowers: Yellow, sometimes reddish-pink with age, heads solitary and discoid, relatively large and showy in hemispheric or bell-shaped heads, disc florets 30-100 or more, corollas to 4 mm long, outermost florets sometimes enlarged and somewhat bilateral, involucres hemispheric to campanulate, 6-12 mm in diameter, phyllaries persistent, thin-herbaceous, lance-ovate to lanceolate or linear-elliptic with acute tips, subequal to equal and distinct, 18-25 in 2 or more series, surfaces loosely woolly, the inner more thin, membraneous, and less woolly, erect or spreading in fruit, receptacles epaleate, convex to conic, with a smooth or finely pitted surface, style-branches truncate, heads terminal, borne singly on slender, glandular-puberulent and bractless peduncles 3-11 cm long.

Fruits: Cypselae (achenes) obpyramidal, to 3 mm long, surfaces glabrous or shaggily hairy with 5 nerves. Pappi of 5 thin, membraneous, deeply lacerate scales, each constituted of 8-15 or more connate bristles, these 3-3.5 mm long.

Ecology: Found on sandy or gravelly soils, on dry slopes, mesas, plains, and in creosote-bush scrub or desert communities, to 5,000 ft (1524 m); flowering January-May and October-December.

Distribution: Arizona, California, Nevada, Utah.

Notes: These handsome and showy, furred annuals have relatively large yellow (aging pink) globose, discoid heads with more or less flattened tops which help this species stand out against deserst landscapes. Kearney and Peebles note this species occurring in Mohave, Maricopa, Pima, and Yuma counties in Arizona.

Ethnobotany: Unknown.

Synonyms: Psathyrotes incisa

Editor: LCrumbacher2012

Etymology: Trichoptilium comes from the Greek trichos, "hair," and ptilon, "feather," in allusion to the dissected pappus-paleae, i.e. the chafflike scales on the receptacle, while incisum means incised, deeply or irregularly cut.

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L.R. Landrum  
Trichoptilium incisum image
L.R. Landrum  
Trichoptilium incisum image
Trichoptilium incisum image
Trichoptilium incisum image
Trichoptilium incisum image