PHYLOGENETIC RELATIONSHIPS AMONG THE ONE-FLOWERED, DETERMINATE GENERA OF BAMBUSEAE (POACEAE: BAMBUSOIDEAE)

Abstract

Bambuseae (woody bamboos), one of two tribes recognized within Bambusoideae (true bamboos), comprise over 90% of the diversity of the subfamily, yet monophyly of the tribe is generally only moderately supported, and phylogenetic relationships within the tribe are poorly understood. In addition, there appears to be some level of conflict between morphological and molecular data within the tribe. We conducted a parsimony analysis of 43 species of Bambuseae, three of Olyreae (herbaceous bamboos), and two outgroup taxa using morphological and plastid rpl16 intron sequence data to (1) further test the monophyly of Bambuseae, (2) test the monophyly of Chusqueinae and Hickelinae (the two one-flowered, determinate subtribes), and (3) examine the apparent conflict between molecular and morphological data sets in the determinate, one-flowered genera of Bambuseae. We recovered a monophyletic Bambusoideae, Bambuseae, Olyreae, and Chusqueinae, although support for Bambuseae remained moderate. Our results suggest that the morphological similarities between Chusqueinae and Hickelinae are homoplasious, but robust resolution of relationships among the major lineages of woody bamboos is still wanting.