2. A. spinulòsus, DC. Perennial, branching, puberulent or glabrate, low; leaves narrow, pinnately or bipinnately parted, the lobes and teeth bristle-tipped; heads small, the appressed scales bristle-tipped; achenes pubescent.—Minn. to Kan., and southward.
3. A. divaricàtus, Gray. Annual, 1–2° high, slender and diffusely paniculate, rough-pubescent or glabrate; leaves rigid, narrow, entire or with a few spinulose teeth, much reduced above; heads small and narrow, the appressed scales subulate, attenuate; achenes silky.—Southern Kan.
16. BIGELÒVIA, DC. Rayless Golden-rod.
Heads 3–4-flowered, the flowers all perfect and tubular. Involucre club-shaped, yellowish; the rigid somewhat glutinous scales linear, closely imbricated and appressed. Receptacle narrow, with an awl-shaped prolongation in centre. Achenes somewhat obconical, hairy; pappus a single row of capillary bristles.—Flowers yellow. Leaves scattered, oblanceolate or linear, 1–3-nerved. A large western genus, few species approaching our limits. (Dedicated by De Candolle to Dr. Jacob Bigelow, author of the Florula Bostoniensis, and of the American Medical Botany.)
1. B. nudàta, DC. A smooth perennial; the slender stem (1–2° high) simple or branched from the base, naked above, corymbose at the summit, bearing small heads in a flat-topped corymb.—Low pine barrens, N. J. (rare), and southward. Sept.
17. SOLIDÀGO, L. Golden-rod.
Heads few–many-flowered, radiate; the rays 1–16, pistillate. Scales of the oblong involucre appressed, destitute of herbaceous tips (except n. 1 and 2). Receptacle small, not chaffy. Achenes many-ribbed, nearly terete; pappus simple, of equal capillary bristles.—Perennial herbs, with mostly wand-like stems and nearly sessile stem-leaves, never heart-shaped. Heads small, racemed or clustered; flowers both of the disk and ray (except n. 6) yellow. (Name from solidus and ago, to join, or make whole, in allusion to reputed vulnerary qualities.) Flowering in autumn.
Conspectus of Groups.
Heads small, sessile in flat-topped corymbs; leaves linear 41, 42
Heads all more or less pedicelled.