From Plant Press, Vol. 18, No. 3, July 2015.

In a recent publication in the Journal of Systematics and Evolution, Paul Peterson, Konstantin Romaschenko, and Yolanda Herrera Arrieta revealed a new phylogenetic tree for Bouteloua(Poaceae: Chloridoideae: Cynodonteae; Boutelouinae), a genus of forage grasses found in the Americas. Bouteloua is made up of 60 species with a center of diversity in northern Mexico.

Yolanda Herrera Arrieta (photo taken by P.M. Peterson, Oct 2000) and Bouteloua herrera-arrieta P.M. Peterson & Romasch. A. Habit. B. Inflorescence branch. C. Upper glume. D. Florets. Drawn by Alice Tangerini.

The new phylogenetic tree was constructed via genetic analysis of 209 samples, including 59 species (206 individuals) in Bouteloua. Using a combination of two plastid spacers and nuclear ITS (ribosomal internal transcribed spacer), the researchers were able to produce a tree that supported a previous phylogeny but is better resolved with strong support for 11 clades. The resultant new subgeneric classification of the species of Bouteloua includes 10 sections and two subsections. Incongruence between the plastid and nuclear phylogenies suggest at least two ancient hybridizations which will require further study.

Based on the new phylogeny and unique morphological characteristics, Peterson’s group described a new species: Bouteloua herrera-arrietae. The new species is known only from the Sierra Madre Oriental in Mexico where it occurs on calcareous rocky hills. It is named for Dr. Yolanda Herrera Arrieta, a coauthor who has completed a revision of Bouteloua and floristic studies on grasses in Chihuahua, Durango, Mexico, and Zacatecas.