Systematics Section / ASPT
Clark, Lynn G. .
A Revision of Chusquea subg. Rettbergia (Poaceae: Bambusoideae: Bambuseae).
Chusquea, a Neotropical genus of woody bamboos characteristic of montane forests, includes nearly 140 described species. It is distinguished by the presence of solid culms; multiple, dimorphic buds per node; determinate spikelets with one fertile floret and no rachilla extension; and a base chromosome number of x = 10. Recent phylogenetic analysis of plastid rpl16 intron sequences and morphological characters provides strong support for 1) the sister relationship of Neurolepis (another one-flowered Neotropical genus) and Chusquea; 2) monophyly of Chusquea as currently defined; and 3) a sister relationship between Chusquea subg. Rettbergia (the Rettbergia clade) and the remainder of the genus (the Euchusquea clade comprising subg. Chusquea and subg. Swallenochloa). The dichotomy between the Rettbergia and Euchusquea clades is well supported by molecular data, but only the Rettbergia clade receives support from morphological data in the form of two synapomorphies (presence of dome-shaped central buds and connate lemma tips). The Rettbergia clade additionally is characterized by a clambering habit, infravaginal branching, and usually geniculate subsidiary branches. Capitate or congested synflorescences are found in a majority of species. Chusquea subg. Rettbergia is primarily Brazilian (with one species in Colombia) and its 12 or so species tend to grow from sea level to 1600 (-1900) m in Atlantic forests, lower than most other members of Chusquea. Chusquea oligophylla and C. oxylepis are perhaps the most widespread and common members of the subgenus, whereas C. pulchella and C. arachniformis (Colombia) appear to be narrow endemics.
Log in to add this item to your schedule
1 - Iowa State University, Department of Ecology, Evolution & Organismal Biology, 253 Bessey Hall, Ames, Iowa, 50011-1020, USA
Presentation Type: Oral Paper
Location: Salon J - Austin Grand Ballroom/Hilton
Date: Monday, August 15th, 2005
Time: 11:15 AM