Posoqueria latifolia of auct., non Solena latifolia Rudge nec Posoqueria latifolia (Rudge) R. & S.
Type. “Forets humides de la Chinantla, pres de bourgs indiens de Teotal-caingo et Choapam (cordillere orientals d’Oaxaca), de 2,000 a 3,500 pieds,” Mexico, H. Galeotti 1580.
This species has been generally considered synonymous with Posoqueria latifolia, but a careful study of its characters, especially the densely conspicuously papillose-puberluent interior of the corolla-tube, shows it to be quite distinct from P. latifolia. The type of the species from the mountains of Oaxaca, Mexico, is the variation in the higher altitudes farther south in Central America. In South America, this montane species with the densely papillose-puberulent interior of the corolla-tube, has also passed as P. latifolia, but was carefully described by Karsten from Venezuela in 1S4S as Stannia formosa. A variation with elongate corollas, but belonging to the same complex, was described by Standley from Colombia as P. maxima. In all these areas, P. coriacea occurs as a montane species of the higher altitudes, whereas P. longiflora, P. latifolia, P. trinitatis, P. panamensis, and the other species treated in this study, are inhabitants of lower elevations nearer sea level.
Since the variations in South America are found to be part of the same complex as P. coriacea, they are here treated as subspecies, as indicated by the following key.