Plants 28-60 cm; caudices woody. Stems 1-3+ , erect, flexuous in proximal arrays, moderately to densely villous. Leaves: basal withering by flowering; basal and proximal cauline abruptly tapering to winged, villous petioles (petioles ± 1 / 2 or less total leaf length), blades broadly ovate to spatulate, 46-80(-90) × 23-47(-55) mm, margins serrate [teeth 6-12(-15)], abaxial faces moderately villous, more so along nerves, adaxial sparsely to moderately villoso-strigose; distal cauline petiolate, similar to proximal or more elliptic, 27-45 × 13-20 mm, margins entire to slightly serrate. Heads 10-30, in short axillary and terminal racemiform/paniculiform clusters. Peduncles 3-5 mm, sparsely strigose; bracteoles 1-3 scattered, ovate. Involucres campanulate, 4.3-6.5(-7) mm. Phyllaries in ca. 3 series, unequal, outer ovate, 1-1.5 mm, obtuse to acute, inner oblong, 1-nerved. Ray florets 3-5; laminae 2.4-4 × 1-1.5 mm. Disc florets 5-8; corollas 2.2-2.5 mm, lobes ca. 1-2 mm. Cypselae (obconic) 1-2 mm, moderately hairy; pappi 2.3-2.8 mm. 2n = 36. Flowering Sep. Sandstone 'rockhouses' (semicircular recesses which extend back under cliff overhangs, typically shaded and damp); of conservation concern; ± 400 m; Ky. Solidago albopilosa is found along the Red River Gorge in Menifee, Powell, and Wolfe counties. It is most similar to S. flexicaulis; it appears weaker and smaller than plants of S. flexicaulis that grow nearby, outside of the rockhouses. Its biology and origins have been discussed in detail (J. R. Beaudry 1959; M. L. Andreasen and W. H. Eshbaugh 1973). Solidago albopilosa is listed as threatened by the U.S. Fish and Wildlife Service (Federal Register 1988).
Much like no. 16 [Solidago flexicaulis L.], but shorter and weaker (mostly 3-5 dm), the stem conspicuously spreading-hirsute, the lvs more hairy, inclined to be subcordate at base, and avg smaller (blade 4-9 נ2.5-5 cm); rays 4-5; 2n=36. Under overhanging cliffs in Powell and Menifee counties, Ky.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.