Pectis cylindrica

(Fernald) Rydberg

in N. L. Britton et al., N. Amer. Fl. 34: 198. 1916.

Common names: Three-rayed or Sonoran chinchweed
Basionym: Pectis prostrata var. cylindrica Fernald Proc. Amer. Acad. Arts 33: 68. 1897
Treatment appears in FNA Volume 21. Treatment on page 225. Mentioned on page 224.

Annuals, 1–20 cm (across or high); herbage not scented. Stems prostrate to ascending (often mat-forming, densely leafy distally), puberulent (in decurrent lines or throughout) or glabrate. Leaves (bluish green) linear to linear-oblanceolate or narrowly oblong, 10–30 × 1.5–4 mm, margins with 2–5 pairs of setae 1–2 mm, faces glabrous (abaxial densely dotted with scattered, circular oil-glands 0.05–0.2 mm). Heads borne singly or in congested, (leafy) cymiform arrays. Peduncles 1–5 mm. Involucres cylindric. Phyllaries coherent (falling together), oblong to oblong-obovate, 6–10 × 2–3 mm (dotted with scattered, elliptic oil-glands 0.05–0.15 mm). Ray florets 3(–4); corollas 3–4 mm (scarcely surpassing phyllaries). Disc florets (3–)7–14; corollas 2.2–2.6 mm (2-lipped). Cypselae 4–5.5 mm, puberulent (distally glandular-puberulent); pappi of 2 (ray) and 5 (disc) lanceolate scales 1.5–3.5 mm. 2n = 48.


Phenology: Flowering Jul–Nov.
Habitat: Deserts, oak-juniper woodlands, grasslands, wash channels, mud flats, lawns, roadsides
Elevation: 700–1500 m

Distribution

V21-541-distribution-map.gif

Ariz., N.Mex., Tex., Mexico (Baja California Sur, Chihuahua, Coahuila, Durango, Nuevo León, Sinaloa, Sonora).

Discussion

Pectis cylindrica (2n = 48) is similar to P. prostrata (2n = 24); the two occasionally grow together (D. J. Keil 1975b). Some herbaria contain mixed collections of the two. No evidence is available of hybrids between the two.

Selected References

None.

Lower Taxa

None.
... more about "Pectis cylindrica"
David J. Keil +
(Fernald) Rydberg +
Pectis prostrata var. cylindrica +
Three-rayed or Sonoran chinchweed +
Ariz. +, N.Mex. +, Tex. +, Mexico (Baja California Sur +, Chihuahua +, Coahuila +, Durango +, Nuevo León +, Sinaloa +  and Sonora). +
700–1500 m +
Deserts, oak-juniper woodlands, grasslands, wash channels, mud flats, lawns, roadsides +
Flowering Jul–Nov. +
in N. L. Britton et al., N. Amer. Fl. +
Undefined (tribe Undefined) subtribe Tageteae +
Pectis cylindrica +
species +