Quercus nixoniana (Fagaceae), a new species in the section Lobatae, from the Sierra Madre de Sur (Mexico)

Abstract

Quercus nixoniana is described as a new species from the states of Jalisco, Guerrero, and Oaxaca at Sierra Madre del Sur, Mexico. It is included in Quercus sect. Lobatae Loudon (red oaks) because of the leaves with a terminal seta, the tomentose endocarp, and the base of the pistillate perianth free, forming a skirt or flange. It resembles Q. salicifolia Nee and Q. crispifolia Trelease in the lanceolate blade, indument, and canescent acorns. A key for distinguishing the three taxa is included.