Head discoid, many-flowered; flowers perfect. Involucral scales linear, equal, in 1 or 2 rows. Receptacle naked. Corolla 5-toothed. Achenes 5-angled; pappus a single row of 5 almost horny oval and obtuse scales.--A smooth perennial, with simple stems, rooting at the base, linear entire leaves in whorls of 4--6, and a terminal head of flesh-colored flowers. (Name composed of σκληρός, _hard_, and λεπίς, _a scale_, from the pappus.) 1. S. verticillàta, Cass.--In water; pine barrens, New Jersey and southward. Aug. 4. MIKÀNIA, Willd. CLIMBING HEMP-WEED. Heads discoid, 4-flowered. Involucre of 4 scales. Receptacle small. Flowers, achenes, etc., as in Eupatorium.--Twining perennials, climbing bushes, with opposite commonly heart-shaped and petioled leaves, and corymbose-panicled flesh-colored flowers. (Named for _Prof. Mikan_, of Prague.) 1. M. scándens, L. Nearly smooth, twining; leaves somewhat triangular-heart-shaped or halberd-form, pointed, toothed at the base.--Copses along streams, E. New Eng. to Ky., and southward. July--Sept. 5. EUPATÒRIUM, Tourn. THOROUGHWORT. Heads discoid, 3--many-flowered; flowers perfect. Involucre cylindrical or bell-shaped, of more than 4 scales. Receptacle flat or conical, naked. Corolla 5-toothed. Achenes 5-angled; pappus a single row of slender capillary barely roughish bristles.--Erect perennial herbs, often sprinkled with bitter resinous dots, with generally corymbose heads of white, bluish, or purple blossoms, appearing near the close of summer. (Dedicated to _Eupator Mithridates_, who is said to have used a species of the genus in medicine.) § 1. EUPATORIUM proper. _Receptacle flat._ [*] _Heads cylindrical, 5--15-flowered; the purplish scales numerous, closely imbricated in several rows, of unequal length, slightly striate; stout herbs, with ample mostly whorled leaves, and flesh-colored flowers._ 1. E. purpùreum, L. (JOE-PYE WEED. TRUMPET-WEED.) Stems tall and stout, simple; leaves 3--6 in a whorl, oblong-ovate or lanceolate, pointed, very veiny, roughish, toothed; corymbs very dense and compound.--Varies greatly in size (2--12° high), etc., and with spotted or unspotted, often dotted stems, etc.,--including several nominal species.--Low grounds; common. Var. amœ̀num, Gray. Low; leaves fewer, ovate or oblong; heads few, 3--5-flowered.--Mountains of Va. and N. Y. [*][*] _Heads 3--20-flowered; involucre 8--15 more or less imbricated and unequal scales, the outer ones shorter; flowers white._ [+] _Leaves all alternate, mostly dissected; heads panicled, very small, 3--5-flowered._ 2. E. fœniculàceum, Willd. (DOG-FENNEL.) Smooth or nearly so, paniculately much-branched (3--10° high); leaves 1--2-pinnately parted, filiform.--Va., near the coast, and southward. Adv. near Philadelphia. [+][+] _Leaves long-petioled, the upper ones alternate; heads 12--15-flowered, in compound corymbs._