Hamelia patens var. glabra Oerst.
-
Authority
Elias, Thomas S. 1976. A monograph of the genus Hamelia (Rubiaceae). Mem. New York Bot. Gard. 26: 81-144.
-
Family
Rubiaceae
-
Scientific Name
-
Discussion
7b. Hamelia patens var. glabra Oersted, Vid. Medd. Nat. For. Kjobenh. 1852: 42. 1853. H. suaveolens H.B.K., Nov. Gen. & Sp. 3:414.1818 (holotype, Humboldt & Bonpland s.n. P). Duhamelia odorata Willd. ex Roem. & Schult. in. L., Syst. Veg. ed. nov. 5: 267. 1819 (holotype, Humboldt & Bonpland s.n. P?). Hamelia nodosa Mart. & Gal., Bull. Acad. Brux. 11: 234. 1844 (holotype, Galeotti 2581, P). H. tubiflora Wernh., Jour. Bot. London 49: 212. 1911 (syntypes, Holton s.n., BM!, GH!, NY!; Purdie s.n. K). H. pedicellata Wernh., Jour. Bot. London 49: 212. 1911 (syntypes Smith 394, BM, 1817 A!, BM, GH!, MO!, NY!, US!; Von Rohr 65, BM; Fender 446, BM; Anderson s.n., K; Guilding s.n., K). H. viridifolia Wernh., Jour. Bot. London49: 213.1911 (holotype, Tonduz 13867, K; isotypes; GH!, US!). H. brachystemon Wernh., Jour. Bot. London 49: 216. 1911 (holotype, Schlim 5417, K; isotype, F!). Type. Nicaragua. San Juan, Oersted s.n. (holotype, C). This glabrous variety of Hamelia patens is centered in northern South America, extending northward to Nicaragua, disjunctly to Mexico, and to Trinidad and Tobago. Variety glabra does not extend as far south in South America as does var. patens. In Mexico and in Central America, especially in work done in Costa Rica and Panama, var. glabra has generally been called H. nodosa, which was formerly considered to be a distinct species closely related to H patens, separated from it by the paucity of trichomes. The South American counterpart of the almost glabrous H nodosa was called H pedicellata, centered in Venezuela and Colombia. These populations generally have slightly smaller corolla tubes, but this very minor difference does not warrant subspecific or specific status. Although the two specific names H. nodosa and H. pedicellata have been widely used, the oldest legitimate varietal name for the semi-glabrous variety of H. patens is var. glabra first named from Central America. Three other species names, H. tubiflora, H. viridifolia, and H. brachystemon have been given to minor variants of the widely distributed H. patens. Leaf color, used by Wernham (1911) as a taxonomic character, was studied extensively. Observations were made on a population of H. patens var. glabra on the small island of Suskatuppu off the Atlantic coast of Panama (San Bias). The soil was extremely poor, consisting mainly of ground shell or ground coral mixed with sand. Vegetation on the island was sparse and scarcely reached 10 m in height in the more luxuriant areas. Large bushes of var. glabra were found growing in completely exposed areas, partially exposed areas, and strongly shaded areas. T he bushes growing in full sun had mature leaves that were bright red in color, while others were red mottled. The immature leaves were green with a slight reddish tinge, darkest along the costa and petiole. In partial sunlight, the bushes exhibited similar coloration patterns, except that the red color was not as intense, and the mature leaves were usually mottled rather than being completely red. Those bushes growing in strongly shaded areas had only green leaves at maturity, with reddish traces on the petioles and costae. Using bushes from the same population on Suskatuppu, these light conditions were simulated in the greenhouses of the Missouri Botanical Garden, the results being identical to those obtained in the field. Similar accounts of the varying degrees of redness of the leaves have been cited by Richards (1952). The evidence indicates that the increased production of red pigment is a protective measure against the strong, direct rays of the sun, and not a stable taxonomic character, as Wernham believed.
-
Distribution
Costa Rica South America| Panama Central America| Colombia South America| Venezuela South America| Guyana South America| Bolivia South America|