The new species Mortoniodendron ocotense is described from northwestern Chiapas, Mexico, where it is a locally abundant tree on karst substrates in seasonal evergreen rain forest. It falls within a group with five previously described species, of which the most closely related is M. uxpanapense. A simplified key to the six species is presented.

A new arborescent species of Croton with accrescent pistillate calyx, Croton pascualii, is described and illustrated from the Pacific Slope of Oaxaca, Mexico.It has certain characteristics in common with Croton oerstedianus, a species included in the section Corylocroton.The proposed new species is characterized by its unisexual cymules, large and broadly ovate imbricate sepals of the pistillate flowers, and capsules ca 12 mm long.The foliage and resin of the new species have a pleasant, persistent aromatic fragrance suggestive of Quararibea or of celery (Apium graveolens).Croton pascualii is thus far known only from the Tropical Moist Semi-Evergreen Forest (selva mediana subperennifolia) of the Pacific Slope of Oaxaca, and has been collected in flower from June to September.Resumen: Se describe Croton pascualii como una especie nueva de la selva mediana subperennifolia de la vertiente del Pacı ´fico de Oaxaca, Me ´xico.La especie nueva tiene ciertas caracterı ´sticas en comu ´n con Croton oerstedianus, de la seccio ´n Corylocroton.Sin embargo, la nueva especie se distingue, de otras descritas para Me ´xico y Centroame ´rica, por las siguientes caracteres: los se ´palos de las flores pistiladas grandes, ovados, imbricados y acrescentes.El follaje y la resina de la nueva especie tienen un aroma agradable parecido al de Quararibea (Malvaceae) o a apio (Apium graveolens).Croton pascualii hasta la fecha se conoce solamente de la vertiente del Pacı ´fico del estado de Oaxaca, donde se ha colectado con flor de junio a septiembre.

Roldana uxordecora is described from Oaxaca, Mexico (Municipio de San Mateo Río Hondo). The genus Roldana is common in the montane regions of the state of Oaxaca (22 species), and this addition to Roldana adds to a list of endemic species, now five, already collected from this montane region.

Phaseolus texensis is a new species known only from rocky canyons of the eastern and southern Edwards Plateau of central Texas. Morphological examination and field observations, in conjunction with current molecular phylogenetic analyses based on nuclear ribosomal and chloroplast DNA sequences and a discrete and limited geographical range, support the taxonomic recognition of this species, which is accordingly described and illustrated here.

A new species of morning glory from southwestern Mexico, Ipomoea cuprinacoma (Convolvulaceae), is described. The species is assigned to Ipomoea series Arborescentes with other stout lianas and trees, and distinguished from I. populina on the basis of slender stems, canescent peduncles and leaf blades, exclusively axial inflorescences, and long, pale-coppery seed hairs.