Aphanostephus ramosissimus var. humilis

Plants 6-15 cm. Involucres 4.7-7.5 mm. Ray florets 26--35. Cypselae (1.1-)1.4-1.6 mm; pappi 0 or minutely ciliate rings 0.1-0.2 mm, sometimes nearly smooth. 2n = 8.

Flowering Apr-Jun(-Oct). Sand and gravel bars, limestone soils, Larrea flats, mesquite savannas, roadsides, disturbed sites; 700-1600 m; Ariz., N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Durango, Nuevo León, Tamaulipas, Zacatecas).

FNA 2006, Wiggins 1964, Kearney and Peebles 1969, Allred and Ivey 2012

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Low annual herb, 5-35 cm tall; stems several, ascending from a rosette; herbage cinereous-puberulous. Leaves: Rosette of oblanceolate, pinnatifid leaves 6-10 mm wide by 3-6 cm long, these soon dying and leaving base of stems naked; cauline (stem) leaves alternate, smaller, entire to pinnatifid, the teeth or lobe tips acute and often faintly apiculate. Flowers: Flower heads small but showy and radiate, with white to lavender rays and yellow discs; flower heads solitary at tips of 1-6 cm long peduncles, these bearing several reduced, bract-like leaves scattered below the flower head; involucres broad, 5-7 mm high by 8-12 mm wide, the phyllaries (involucral bracts) graduated, in 3 series, with greenish puberulent midribs and white or pink- scarious margins; ray flowers 30-40 per head, the ligules (ray petals) 1 mm wide or less and 4-6 mm long, white or often tinged with purple; disk corollas 2 mm long, yellow. Fruits: Achenes broadly obconic, about 1 mm long, brownish, minutely and sparsely appressed-puberulent along low, rounded ribs; topped with a minute, barely discernible, crown of hairs. Ecology: Found on plains, along arroyos and river banks from 1,000-3,500 ft (305-1067 m); flowers March-October. Distribution: s AZ, c and s NM, w TX; south to MEX Notes: With its white to lavender daisy-like flowers and delicate, hairy stems, this species could easily be mistaken for an Erigeron. To distinguish this species, focus on its phyllaries, which are narrow and pointed with a hairy green stripe down the middle and scarious (papery) white to pink edges; they arranged in a few series which are slightly graduated; look also at the ray petals which are generally rounded at the tips with small notches (this is visible on fresh material but less obvious on dried flowers); and pay attention to the seeds, which do not have a pappus of bristles attached to the tops (Erigeron spp and the Aster group have pappus of bristles). Ethnobotany: Unknown Etymology: Aphanostephus is from Greek aphanes, inconspicuous or obscure, and stephanos, crown, alluding to the tiny pappus on the seeds; ramosissimus means very branched; humilis means humble. Synonyms: Aphanostephus arixonicus, A. humilis, A. potosinus, Leucopsidium humile Editor: SBuckley 2010, AHazelton 2017