Schreber's Aster

Eurybia schreberi is rare or extirpated in a many states at the northern limit of its range.

Plants (20–)40–110 cm, in ± dense clones (with sterile rosettes on short rhizomeds); rhizomes branched, long. Stems 1, erect, simple, straight, proximally glabrous or sparsely villous, distally densely villous. Leaves basal and cauline, margins coarsely serrate (proximal) to serrate (distal), strigoso-ciliate, teeth (15–30 per side) mucronulate, apices acuminate, abaxial faces sparsely strigose, long-stipitate-glandular on veins, adaxial sparsely villous, more densely so on veins; basal withering by flowering, petiolate (55–180 mm), bases sheathing, blades broadly ovate, 55–110 × 48–95 mm, bases cordate (with mostly deep, rectangular sinuses); cauline petiolate to (distal) subsessile, petioles (4–100 mm) ± winged, ± clasping, blades ovate to broadly lanceolate, 27–135 × 7–112 mm, bases cordate (sinuses narrower) to rounded or cuneate-rounded; distal (arrays) sessile, ovate to lanceolate, 6–70 × 1–27 mm. Heads 15–100+ in flat-topped, corymbiform arrays. Peduncles sparsely to moderately villous, sparsely glandular; bracts 0–1, linear. Involucres cylindro-campanulate, 5.5–7.5 mm, equal to or shorter than pappi. Phyllaries 23–32 in 4–5 series, oblong (outer) to lanceolate (inner), strongly unequal, bases indurate, dark green zones in distal ¹ / 4 or less (outer), often confined to narrow strip along midnerves or none (inner), margins narrowly scarious, densely villoso-ciliate, apices ± loose, obtuse to rounded, faces glabrous or sparsely villosulous, sometimes sparsely stipitate-glandular. Ray florets 6–12; corollas white, 10.5–13 × 1.5–2.1 mm. Disc florets 12–20(–30); corollas yellow, 5–6.8 mm, slightly ampliate, tubes (3.2–3.8 mm) longer than campanulate throats (1.1–1.9 mm), lobes erect to slightly spreading, lanceolate, (0.9–)1.1–1.5(–1.9) mm. Cypselae brown, fusiform to cylindro-obconic, compressed, 3.2–3.7 mm, ribs 6–12, faces glabrous or sparsely strigillose; pappi of (65–70) orangish to burnt orange (fine, barbellulate, sometimes apically clavellate) bristles 5–6.8 mm, ± equaling disc corolla. 2n = 54.

Aster schreberi Nees, Syn. Aster. Herb., 16. 1818; Biotia glomerata (Nees) de Candolle; Biotia schreberi (Nees) de Candolle; Eurybia glomerata Nees