Plants (20-)40-90(-100) cm; caudices woody. Stems 1-4 , erect, straight, glabrous or moderately hirtello-strigose. Leaves: basal withering by flowering; proximal to mid cauline weakly petiolate or sessile, blades lanceolate to elliptic, (36-)95-150(-180) × (10-)19-43(-60) mm, margins serrate (with (3-)8-20(-36) teeth), faces glabrous or sparsely hairy, more so along nerves; distal cauline sessile, blades narrowly lanceolate to narrowly elliptic, (5-)37-90(-130) × (3.5)5-18(-34) mm, margins entire to sparsely serrate (0-9(-14) teeth), faces glabrous or sparsely hairy, sometimes more pilose along nerves. Heads 20-800 in short axillary and terminal racemiform/paniculiform, non-secund arrays (2-)8.5-38.5(-65) cm. Peduncles 2-6 mm, moderately to densely finely strigose; bracteoles 0-3, linear-oblong. Involucres narrowly campanulate, (5-)5.6-7(-8) mm. Phyllaries in 3-4 series, strongly unequal, outermost 1-1.4(-2) mm, innermost (2.5-)3-4(-4.4) mm, obtuse to acute, 1-nerved. Ray florets 2-4(-6); laminae (2-)2.5-4(-4.6) × 1-2 mm. Disc florets 3-7(-9); corollas mostly 2-3 mm, lobes 1-1.7(-2.4) mm. Cypselae 1-2(-3) mm, sparsely to moderately strigose; pappi (2-)2.7-3.6(-4.5) mm. Solidago curtisii is similar to S. caesia and may be confused with robust, pressed and dried specimens of the latter if they are mounted such that the arching habit cannot be observed.
Plants 3-15 dm from a short and caudex-like to occasionally more elongate rhizome, the stem striate-angled and grooved, glabrous or hairy; lvs chiefly cauline, ±serrate, acuminate, glabrous or evidently hairy, numerous, lanceolate to narrowly elliptic, mostly 10-18 נ1-4(-4.5) cm, 3-10 times as long as wide, tapering to the sessile or obscurely short-petiolate base; infl largely or wholly of axillary clusters shorter than their subtending lvs (or in robust forms many of the clusters elongate and leafy-bracteate), the terminal segment sometimes thyrsoid and nearly naked; invol (2.5-)3-5(-6) mm, glabrous or short-hairy but not glandular, its bracts 1-nerved or obscurely nerved to ±evidently 3-nerved, seldom any of them as much as 1 mm wide at or above midlength; rays (2)3-5(6); disk-fls 4-9; achenes hairy; 2n=18. Mt. woods, but not at the highest elev.; Va., W.Va., Tenn., and Ga. (S. pubens, the hairy phase)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.