Froelichia arizonica Thornb. ex Standl.
Family: Amaranthaceae
Arizona Snake-Cotton,  more...
Froelichia arizonica image

Plants perennial; taproot en-larged, woody. Stems 1-several, ascending or decumbent, often branched distally, 3-10 dm, sericeous-tomentose with white hairs. Leaves usually crowded at base, few on stems, sessile or short-petiolate; blade lanceolate, proximal leaves 3-12 × 0.5-2.5 cm, base attenuate, apex acute or rarely obtuse, scaberulous or canescent adaxially, sericeous-tomentose with bright whitish hairs abaxially. Spikes dense, stout, flowers arranged in 3-ranked spiral; bracteoles dark, glabrous. Flowers (3.5-)4-5.5 mm; perianth lobes narrowly oblong, apex obtuse, or acutish, pubescence dense, bright white; filament lobes stramineous or darkened, blunt. Utricles narrowly or broadly winged laterally, 2.5-5.5 × 3-4.5 mm, longer than broad, wing margins irregularly dentate, 1 or both surfaces of perianth with 1 or more basal tubercles or spines.

Flowering year-round. Open rocky or gravelly hillsides; 700-2200 m; Ariz., N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Nuevo León).

Wiggins 1964, Kearney and Peebles 1969, FNA 2004

Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Perennial herb, 20-100 cm tall, from a large woody taproot; stems 1-several, stout, erect, branching from base, with silky tomentose hairs.

Leaves: Opposite, crowded near base of stems, sessile or petiolate, the petioles to 1.5 cm; blades thick, oblanceolate, with cuneate bases and obtuse to acute tips, 2-10 cm long and to 1-2 cm wide, the lower surface densely silky-lanate, and the upper surface sparsely lanate to glabrate.

Flowers: Brownish, bisexual, in numerous erect wooly spikes 1-4 cm long; the spikes elevated on peduncles 10-30 cm long; bracts subtending each flower ovate, 2 mm long, grayish brown, scarious, with tufts of wool protruding from within; perianth tubular with lance-linear lobes, glabrous, 2 mm long, brownish.

Fruits: Utricle ovoid, densely lanate with yellowish or rusty hairs, to 6 mm long.

Ecology: Found on dry slopes, often in gravelly or rocky soils from 3,500-5,500 ft (1067-1676 m); flowers July-October.

Distribution: se AZ, s NM, sw TX; south to c MEX.

Notes: Distinctive as tall, thin perennial with silky hairs all over; thick oblong leaves mostly crowded near the base of the plant, leaving much of the stem leafless and scape-like; a branched inflorescence with dense spikes at the ends of long erect peduncles, the flowers and seeds dense with long, tangled, bright-white hairs that resemble bursting cotton tufts. It is similar to its congener F. gracilis, but that species is an annual with slender stems and narrow leaves.

Ethnobotany: Unknown

Etymology: Froelichia honors German physician and botanist Joseph Aloys von Froelich (1766-1841), while arizonica means of or from Arizona.

Synonyms: None

Editor: SBuckley 2010, FSCoburn 2014, AHazelton 2015