Slender Aster

Eurybia compacta may be extirpated from much of its original range (Georgia, Maryland, South Carolina, Virginia) and may now be of conservation concern. It is present on the Atlantic coastal plains and outer Piedmont. A. Cronquist (1980) stated that it approaches E. surculosa on one hand, and E. avita and E. paludosa on the other. This reflects the close affinity between sections Calliastrum and Heleastrum (see above). I have seen no voucher for the Alabama report.

Plants 15–50(–70) cm, in clumps, eglandular; caudices thickened, woody, ovoid to spheric. Stems 1–8+, erect, simple, strict, glabrescent, usually ± densely villous distally. Leaves basal and cauline, thick, firm (only midnerves conspicuous), margins entire or nearly so, indurate, scabrous, apices indurate, mucronate, faces scabrous (especially distal) to sometimes glabrous, adaxial sometimes villous (especially proximal) at least along midnerves; basal often withering by flowering (bases sometimes marcescent), petioles erect, longer than blades, bases sheathing, winged, ciliate, blades narrowly elliptic to ovate or obovate, 20–70 × 8–20 mm, bases cuneate, margins sometimes crenulate-serrulate, teeth mucronate, apices obtuse to rounded; cauline usually sessile, sometimes subsessile (ascending), lanceolate to oblanceolate, 15–80(–90) × 2.5–12 mm, bases sheathing to auriculate-clasping (distal), apices acute. Heads 3–55+ in flat-topped, corymbiform arrays, branches ascending, slender. Peduncles slender, villous; bracts 1–2, often 1 near heads, leaflike (bases sometimes indurate and white as in phyllaries). Involucres cylindro-campanulate, 6.5–9 mm, slightly shorter than pappi. Phyllaries 24–35 in 4–5 series, oblong (outer) to lanceolate (inner), unequal, coriaceous (outer) to membranous (inner), bases indurate, rounded (outer), margins hyaline, narrowly scarious, ± erose, ciliate (outer), apices reflexed, green (except innermost), purple-margined, less scarious, rounded or obtuse (outer) to acuminate (inner), mucronate, abaxial faces glabrous or obscurely puberulent, eglandular. Ray florets (5–)8–14; corollas blue-violet to rose-purple or bluish, often pale, 5–8(–10) × 1–1.8 mm. Disc florets 10–20; corollas pale yellow, 5.5–6.2 mm, not ampliate, tubes longer than narrowly funnelform throats, lobes triangular, 0.65–0.9 mm. Cypselae stramineous, cylindro-obconic, 1.75–2.6 mm, ribs 9–12 (crowded), faces glabrate to strigillose; pappi of tawny to cinnamon bristles 5.9–6.2 mm, equaling disc corollas. 2n = 18.

Aster gracilis Nuttall, Gen. N. Amer. Pl. 2: 158. 1818, not Eurybia gracilis Bentham 1837; Aster surculosus Michaux var. gracilis (Nuttall) A. Gray

Eurybia compacta, commonly known as the slender aster, is an herbaceous perennial native to the eastern United States from New Jersey to Georgia. It is commonly found along the coastal plain in dry sandy soils, especially in pinelands. While it is not considered to be in high danger of extinction, it is of conservation concern and has most likely been extirpated from much of its original range. The slender aster was for a long time considered to be a variety of E. surculosa, but Guy Nesom's recent research within the genus has shown that it is distinct enough to be treated as a species. It has also been shown to be related to E. avita and E. paludosa.

Eurybia compacta is a perennial up to 70 cm (28 inches) tall, the stem becoming woody with age. The flowers emerge from midsummer to the beginning of fall, with as many as 55 flower heads in a flat-topped array. Each head contains 5-14 pale blue, light violet or reddish purple ray florets surrounding 10-20 pale yellow disc florets.