in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 429. 1849.
Herbs, perennial, viscid-pubescent, from tuberous taproots. Stems erect to spreading, unarmed, without glutinous bands on internodes. Leaves long petiolate, unequal in each pair, thick and fleshy, base ± asymmetric. Inflorescences axillary and terminal, long pedunculate, capitate; bracts 6–20, forming involucre, subtending cluster of more than 3 flowers; outer bracts ovate or lanceolate, apex acuminate or narrowly acute; inner bracts persistent, not accrescent, distinct, narrower than outer, herbaceous. Flowers bisexual, chasmogamous and/or cleistogamous; cleistogamous perianth small green dome atop developing turbinate base; chasmogamous perianth radially symmetric, orange-red, or all yellow, funnelform, constricted beyond ovary, abruptly expanded to 5-lobed limb; stamens 5–8, slightly exserted; styles exserted slightly beyond stamens; stigmas capitate. Fruits radially symmetric, turbinate, constricted beyond base, apex umbonate, stiffly coriaceous; ribs 10 low, rounded, each swollen at junction of distal, umbonate portion, glabrous, smooth, without glands.
sw United States, n Mexico
"thick" is not a number.