Cuphea inflata (Lythraceae), a New Species from Mexico

Abstract

Cuphea inflata S. Graham is described as a new species of sect. Heterodon from Nayarit, Jalisco, and Sinaloa. It is distinguished from its closest relative, C. leptopoda Hemsl., by its secund or pyramidal inflorescence, wine-purple floral tube inflated at maturity, and chromosome number, n = 10. Recognition of a new species of Cuphea from Nayarit, Mexico, is supported by new morphological and cytological data gathered in recent field work. Earlier collections of the species were determined as C. leptopoda Hemsl. or as having affinities with that species. Cuphea inflata S. Graham, sp. nov., figures 1-4. Herba annua; folia anguste elliptica ad elliptica; folia floralia abrupte minora, bracteiformia. Inflorescentia terminalia, secundiflora vel pyramidalis, panicularis 1-multiflores composita. Calyx 12-17 mm longus, dorso manifeste vinosus in statu vivo, atro-purpureus in statu sicco; calyx fructifer ampulliformis, inflatus infra medium, pallescens. Petala 6, duo dorsalia vinosa, 4 ventralia lilacina. Ovula 3. n = 10. TYPE: Mexico, Nayarit, 3 km E of Santa Maria del Oro on road to the lake, oak zone, open sunny areas along roadsides, 20 Aug 1978, S. Graham 608 (holotype: MICH; isotypes: GOET, MEXU). Herbaceous annual, erect, 20-75 cm tall, sparsely branched below, the branches shorter than the main stem; stems green, very viscid, bearing dense, glandular, purple hairs in the inflorescence. Petioles 10 (5-20) mm long; leaf blades narrowly elliptical to elliptical, 30-65 mm long, 1230 mm wide, minutely uniformly scabrous on upper and lower surfaces, the base acute, the apex acuminate;' uppermost leaves abruptly reduced in size becoming linear, ciliated bracts of the terminal inflorescence. Inflorescence compound, shortto long-paniculate, secund or pyramidal on mature plants, the branches of the panicle becoming progressively shorter and fewer-flowered toward the apex of the plant, the longest branches up to 8 cm long with ca. 20 flowers, most branches 2-3 cm long with ca. 5 flowers; flowers 1-5 per node; pedicels 1-2 mm long, bibracteolate, the bracteoles composed of 1-3 hairs, scarcely developed. Calyx 12-17 mm long, distinctly wine-colored, drying purple-black, the ribs dark purple bearing purple glandular hairs, the base rounding, barely spurred, the lower distal end saccate, the calyx ampullaceous at maturity, the proximal end becoming exceptionally inflated and pale pink in con-