Stebbins' Desertdandelion

Malacothrix stebbinsii grows in the Mojave Desert (Borrego area, California) and the Sonoran Desert (Santa Catalina, Mazatzal, Baboquivari, and Santa Rita mountains, and elsewhere in Arizona).

Annuals, 5–60 cm. Stems 1–5+, ± erect, branched distally, sparsely leafy, glabrous. Cauline leaves: proximal obovate, pinnately lobed (lobes 3–5+ pairs, triangular to oblong or linear), not fleshy, ultimate margins entire or dentate, faces glabrous; distal reduced (usually with 2 lobes near bases). Calyculi of 5–8+, ovate to lanceolate bractlets, hyaline margins 0.05–0.2 mm. Involucres ± campanulate, 7–10 × 3–6 mm. Phyllaries 16–20+ in 2–3 series, lanceolate to lance-linear, hyaline margins 0.05–0.1 mm wide, faces glabrous. Receptacles not bristly. Florets 19–70; corollas usually yellow, sometimes white, 6–7 mm; outer ligules exserted 1–2 mm. Cypselae ± cylindro-fusiform, 1.7–2.3 mm, ribs extending to ca. 0.1–0.2 mm short of apices (minutely hirtellous or muriculate), ± equal (distal 0.1–0.2 mm of cypselae smooth); pappi persistent, of 8–15+, needlelike teeth plus 1(–2) bristles. Pollen 70–100% 4-porate. 2n = 28.

Malacothrix clevelandii A. Gray var. stebbinsii (W. S. Davis & P. H. Raven) Cronquist

Malacothrix stebbinsii is a species of flowering plant in the family Asteraceae known by the common name Stebbins' desertdandelion. It is native to the southwestern United States and northern Mexico where it grows in deserts, scrub, and woodlands. It is an annual herb producing a hairless stem up to about 60 centimeters in maximum height. The leaves are lined with narrow lobes. The inflorescence is an array of flower heads with ray florets under a centimeter long and white to light yellow in color.