Thinleaf Late Purple Aster

Perennials, 50–130 cm, cespitose; with short, thick, woody caudices, not rhizomatous. Stems 1, erect to arching, light to dark brown, soft-hairy, hairs ascending- to spreading- stipitate-glandular distally. Leaves (dark green) thin, almost membraneous; basal early deciduous, sessile or subpetiolate, blades spatulate to obovate, 80–140 × 20–30 mm, bases cuneate, margins entire to ± serrate, scabrous, apices acute; proximal cauline withering by flowering, sessile, blades panduriform, (20–)30–70(–110) × 10–30(–35) mm, bases auriculate-clasping, margins entire (flat), sparsely villoso-ciliate, apices acute, faces finely sparely villous or scabrous, stipitate-glandular; distal sessile, blades (rugose-veined when fresh) ovate to lanceolate, 75–125(–140) × 15–35(–40) mm, bases strongly cordate-clasping to auriculate-amplexicaul, margins entire (± undulate), apices acute, acuminate to merely mucronate, faces sparsely strigose, moderately so along veins, sparsely to moderately stipitate-glandular. Heads in crowded, paniculiform arrays, branches often initially patent then ascending. Peduncles short (less than 4 cm), strigose, stipitate-glandular, bracts linear-lanceolate, ascending-appressed, grading into phyllaries. Involucres cylindric, 5.5–7.5(–8) mm. Phyllaries in 4–6 series, linear-lanceolate, unequal, bases (tan) ± indurate in proximal ¹ / 3 – ¹ / 2 , margins hyaline, erose, distally scabro-ciliolate to ciliolate, green zones covering distal ¹ / 2 , apices outer obtuse to acute, inner acuminate, purplish, faces sparsely strigillose, usually moderately to densely stipitate-glandular, rarely sparsely so. Ray florets 9–17; corollas light to dark reddish purple, laminae 10–18(–20) × 1–3 mm. Disc florets 15–35; corollas white with purple lobes, 6–8 mm, lobes triangular, 1–1.5 mm. Cypselae dark brown to black, obovoid, not compressed, 2.5–4 mm, 7–10-nerved, faces densely strigose along ribs; pappi tan to tawny, sometimes slightly purplish-tinged, 6–8 mm. 2n = 20.

Aster phlogifolius Muhlenberg ex Willdenow, Sp. Pl. 3: 2034. 1803; Aster patens Aiton var. phlogifolius (Muhlenberg ex Willdenow) Nees; Virgulus patens (Aiton) Reveal & Keener var. phlogifolius (Muhlenberg ex Willdenow) Reveal & Keener

Symphyotrichum phlogifolium (formerly Aster phlogifolius) is a species of flowering plant in the family Asteraceae native to the eastern United States. Commonly known as thin-leaf late purple aster, it is a perennial, herbaceous plant that may reach heights between 50 and 130 centimeters (1+3⁄4 and 4+1⁄4 feet). Its flowers have light to dark reddish-purple ray florets and white disk florets with purple triangular lobes.