Beaucarnea sanctomariana (Nolinaceae), a New Micro-Endemic Species of Ponytail Palm from the Isthmus of Tehuantepec, Oaxaca, Mexico

Abstract

A new species of ponytail palm, Beau- carnea sanctomariana (Nolinaceae), is described and illustrated. With this addition, the neotropical genus Beaucarnea now has 10 species. It occurs in tropical deciduous forests in the biodiversity hot- spot area known as the Chimalapas in the Tehuan- tepec Isthmus, Oaxaca, Mexico. The new taxon is similar to Beaucarnea recurvata Lemaire and to Beaucarnea hiriartiae L. Hernindez, but differs from both in its smaller flowers and fruits (the smallest in the entire genus), and in the articulation of the pedicel in both staminate and pistillate flow- ers. In addition, B. sanctomariana differs from B. recurvata in the smaller trunk bases without but- tresses, shorter leaves, and undulate bracts of the inflorescence, and from B. hiriartiae in having widely conical trunk bases, rugose bark, smooth leaf surface, larger inflorescence stalks, and shorter inflorescence branches. A discussion of field char- acters is presented.