Symphyotrichum depauperatum (Fernald) G.L. Nesom
Family: Asteraceae
Serpentine American-Aster
[Aster depauperatus Fernald,  more...]
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Perennials, 20-50 cm, colonial or cespitose; branched rhizomatous. Stems 1-3+, erect (straight, brittle), glabrate. Leaves thin, margins ciliate, abaxial faces glabrous or glabrate, adaxial sparsely strigose; basal withering by flowering (new rosettes developing at flowering), sessile, blades lanceolate to oblanceolate or spatulate, 20-40+ × 3-5+ mm, bases attenuate, margins sparsely serrate to subentire, strigose-ciliate, apices acute to obtuse; proximal cauline usually withering by flowering, sessile, blades linear-oblanceolate, ca. 30 × 2 mm, bases tapering, margins entire, scabrous, apices acute; distal sometimes withering by flowering, sessile, blades linear, 10-30 × 1.5-5 mm, reduced distally, bases cuneate or not tapering, margins entire, apices acute, ± mucronulate. Heads in open, wide, paniculiform arrays, branches arching, sometimes ± secund, abundantly bracteate. Peduncles long, gradually reduced distally on branches, glabrous or glabrate, bracts 3-17+, linear, mucronate. Involucres cylindro-campanulate, (3.2-) 3.4-4 (-4.3) mm. Phyllaries in 3-5 series, oblong-lanceolate, unequal, bases indurate 1 / 2 - 3 / 4 , margins narrowly scarious, slightly or not erose, sparsely ciliolate or not distally, green zones lanceolate, apices acute, involute, slightly spreading, faces glabrous. Ray florets 7-14; corollas usually white, seldom pink, laminae (3-)3.8-5.4(-6.2) × 0.5-1.1 mm. Disc florets 7-17; corollas yellow becoming brown, (2.2-)2.5-2.9(-3.1) mm, tubes shorter than narrowly funnelform throats, lobes lanceolate, 0.3-0.6(-0.9) mm. Cypselae yellowish brown, obovoid, ± compressed, ± 1.2-1.3 mm, 3-4-nerved, faces sparsely to moderately strigillose; pappi white (yellowish), 2.4-3.3 mm. 2n = 16.

Flowering Aug-Oct. Serpentine or diabasic soils; of conservation concern; 400-1000 m; Md., N.C., Pa.

Symphyotrichum depauperatum is federally listed in the United States.

Similar to no. 22 [Aster parviceps (Burgess) Mack. & Bush], but glabrous throughout, and more slender, wiry, and diffuse, only 1-4 dm, all the cauline lvs (except the numerous, much reduced, subulate ones of the infl) generally deciduous by anthesis; heads 16-32-fld, the rays 9-16, from 2 fewer to 3 more than the disk-fls; 2n=16. On serpentine in se. Pa. and adj. Md.; reputedly disjunct on diabase in Granville Co., N.C.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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