Tripterocalyx
Hooker’s J. Bot. Kew Gard. Misc. 5: 261. 1853.
Herbs, annual, viscid-pubescent to nearly glabrous, from slender or stout and ± woody taproots. Stems decumbent to semierect, unarmed, without glutinous bands on internodes. Leaves petiolate, unequal in size in each pair; blade ± thick and succulent, base usually asymmetric. Inflorescences axillary, pedunculate, capitate clusters; receptacle flat to somewhat rounded-conic, with short, pedicel-like projections; flowers maturing from one side of inflorescence to other; bracts persistent, not accrescent, 5–10, distinct, thin and translucent, forming an involucre, linear-lanceolate to ovate, broad. Flowers bisexual, chasmogamous; perianth radially symmetric, funnelform or salverform, constricted beyond ovary, abruptly expanded to 4–5-lobed limb; stamens (3–) 4–5, included; styles included; stigmas linear. Fruits fusiform, indurate throughout, or spongy on exterior, minutely puberulent or glabrous; wings 2–4, translucent, prominently veined, scarious, extending beyond apex and/or base of body; sulci smooth or coarsely rugose.
Distribution
North America (including n Mexico)
Discussion
Species 4 (4 in the flora).
Selected References
Lower Taxa
Key
| 1 | Fruits usually with 2 wings, body occasionally ribbed laterally, extending prominently into wings | Tripterocalyx crux-maltae |
| 1 | Fruits usually with more than 2 wings, body often ribbed laterally, lateral ribs, if extending into wings, only slightly raised | > 2 |
| 2 | Perianth tube 6-18 mm; perianth limb 3-5 mm diam., lobes inconspicous | Tripterocalyx micranthus |
| 2 | Perianth tube 12-30 mm; perianth limb 8-13 mm diam., lobes over 1.5 mm, showy | > 3 |
| 3 | Perianth limb pale pink to magenta; fruits usually over 20 mm | Tripterocalyx carneus |
| 3 | Perianth limb white adaxially, white to pink abaxially; fruits usually 20 mm or less | Tripterocalyx wootonii |
"thick" is not a number."broad" is not a number. "thin" is not a number.