Cladistic Parsimony Analysis of Internal Transcribed Spacer Region (nrDNA) Sequences of Bouteloua and Relatives (Gramineae: Chloridoideae)

Chloridoideae) employing cladistic parsimony analysis of nuclear ribosomal internal transcribed spacer region (ITS1 + 5.8S + ITS2) DNA sequences. Included were Aegopogon (2 of 4 species), Bouteloua (34 of 42), Buchloë (1 of 1), Buchlomimus (1 of 1), Cathestecum (2 of 4), Cyclostachya (1 of 1), Griffithsochloa (1 of 1), Hilaria (1 of 7), Opizia (2 of 2), Pentarrhaphis (2 of 3), Pleuraphis (2 of 3), Pringleochloa (1 of 1), Soderstromia (1 of 1), and five outgroup genera/species for a total of I8 genera, 56 species, and ten varieties. In all, the ITS region of 72 plants was sequenced and analyzed utilizing PAUP. Aegopogon, the Hilaria-Pleuraphis clade, and Tragus (an outgroup representative) formed a tetratomy with a clade containing the remaining ingroup taxa. Neither Bouteloua nor its two subgenera, Bouteloua and Chondrosium, were found to be monophyletic. Bouteloua chondrosioides was sister to Opizia. Bouteloua rigidiseta formed a clade with Buchlomimus and Pringleochloa. Bouteloua eludens formed a clade with Buchloë, Cathestecum, Griffithsochloa, Pentarrhaphis, and Soderstromia. Bouteloua annua and B. aristidoides (subg. Bouteloua) formed a clade with B. eriopoda, B. eriostachya, B. hirsuta, and B. pectinata (subg. Chondrosium). Bouteloua juncea, which has been included in the B. curtipendula complex, was not a member of that clade. No new circumscriptions were proposed, although recognition of Bouteloua in the broad sense, with Chondrosium reduced to synonymy, was advocated. The findings suggested homoplasy in morphological, anatomical, and breeding system traits