Solidago rigida subsp. glabrata
Canad. J. Bot. 66: 1807. 1988.
Stems 40–95 cm. Leaves and stems glabrous or hispid (stems 0–25 hairs/mm2; leaves 0–20 hairs/mm2). Leaves: basal to 250 × 40 mm; mid to distal lanceolate to ovate, sometimes rhombic, thin. Heads usually compact, flat-topped arrays (2–) 4–14 (–24) × 5–15 (–24.5) cm. Peduncles sparsely to moderately hispid. Phyllaries outer glabrous; inner linear-oblanceolate, 0.8–1.4 mm wide, glabrous. Disc corolla lobes 1–1.6 mm. Cypselae glabrous. 2n = 18.
Phenology: Flowering Sept–Oct(–Nov).
Habitat: Prairies, glades, savannas, dry open areas, especially on calcareous soils
Elevation: 0–300 m
Ala., Ark., Ga., Ky., La., Miss., Mo., N.C., Ohio, S.C., Tenn., Tex.
Apart from the differences stated above, subsp. glabrata is quite similar to subsp. rigida. Oligoneuron corymbosum Small is illegitimate.
"thin" is not a number.