Chamaesaracha coronopus

Stems decumbent to ± erect, often cinerescent or purplish, 1–5 dm. Herbage glabrous or sparsely pubescent, hairs white and short-stellate, eglandular. Leaves subsessile; blade linear-lanceolate, 2–10 × 0.5–1.5 cm, length 4–10 times width, margins sinuate to deeply lobed. Inflorescences 1–2-flowered. Flowers: calyx 4–5 mm, pubescent, especially along lobe margins; corolla 10–15 mm diam. Berries 5–8 mm diam. 2n = 48, 72.

Phenology: Flowering Mar–Oct (mostly late spring–early summer, depending on rain).
Habitat: Dry, open grasslands, coniferous woodlands, sagebrush scrub.
Elevation: 0–2300 m.

Ariz., Calif., Colo., N.Mex., Okla., Tex., Utah, Mexico (Chihuahua, Coahuila, Nuevo León, Sonora, Tamaulipas, Zacatecas).

Discussion

Chamaesaracha coronopus is widespread and frequent within its range. The species is highly variable in leaf shape, vestiture, and stature; it is characterized by the long-linear, deeply incised leaf blades four or more times as long as wide. Plants are glabrous or slightly pubescent, with short-stellate hairs that appear as tufts emerging from the leaf surface. Most populations of C. coronopus have 2n = 48; populations with 2n = 72 are known from southern Texas, the Big Bend region of western Texas, and southern Arizona. J. Henrickson (2009) described C. arida from New Mexico, citing only the type; that entity and populations comparable to it are here included in C. coronopus. B. L. Turner (2015) described C. felgeri from one population in southern Arizona and cited another collection from southern Texas; he suggested that some might consider C. felgeri an edaphic ecotype. With the data available, that suggestion is favored and those populations are included within C. coronopus.

Selected References

None.

Lower Taxa