(Torrey) Hooker

Hooker’s J. Bot. Kew Gard. Misc. 5: 261. 1853.

Common names: Sand -puffs
Etymology: Greek tri, three, pteron, wing, and calyx, in reference to the perianth
Basionym: Tripterocalyx Torrey in J. C. Frémont, Rep. Exped. Rocky Mts., 92. 1843
Treatment appears in FNA Volume 4. Treatment on page 70. Mentioned on page 16.

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.


North America (including n Mexico).


Species 4 (4 in the flora).


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