Abstract Detail

Systematics

Attigala, Lakshmi [1], Leandro, Thales [2], Scatena, Vera [2], Clark, Lynn [3].

The use of foliar micromorphology and anatomy in a taxonomic revision of the Chusquea ramosissima Group (Poaceae: Bambusoideae) from South America.

Chusquea (subtribe Chusqueinae) is recognized as a well-supported yet very diverse genus. Currently, there are 175 described species within Chusquea, most of which are characteristic of montane forests throughout Mexico, Central and South America, and the Caribbean, with some species occurring in high altitude grasslands and lowland tropical forests or in temperate forests at higher latitudes (both north and south). A recent molecular phylogenetic study provides evidence for four major clades within Chusquea: (i) subg. Magnifoliae, (ii) subg. Platonia; (iii) subg. Rettbergia; and (iv) the Euchusquea clade, which includes ca. 75% of the species diversity in the genus. Within the Euchusquea clade five minor clades are well supported even though their relationships are still challenging due to conflicting morphological and molecular evidence. The Chusquea ramosissima clade is one of these five minor clades, and consists of three sampled species (Chusquea ramosissima, C. tenella, and C. longispiculata). The first two plus two other species (C. tenuiglumis and Chusquea sp. nov.) comprise the C. ramosissima Group while the third species plus several others comprise the C. meyeriana Group. All of these species are distributed across South America mainly in Brazil, Bolivia, Paraguay, Uruguay and Argentina. The current study focuses on both macro and micro-morphological as well as anatomical analyses of the C. ramosissima Group, which is defined by the presence of pseudopetiolate culm leaf blades, a feature otherwise unique within Chusquea. We studied the macromorphology of this group following conventional methods and its leaf blade micromorphology using scanning electron microscopy (SEM) and light microscopy (clearings). Further, the leaf blade anatomy in cross section was also examined with light microscopy. Several macromorphological characters differentiate the C. ramosissima Group from the remaining species of Chusquea and microstructural characters demonstrate that epidermal features, mainly relating to the stomatal apparatus, as seen on both adaxial and abaxial surfaces proved to be valuable in distinguishing these species, including providing support for the recognition of the new species from Bolivia, which has not yet been collected in flower.

1 - Iowa State University, Ecology Evolution and Organismal Biology, 2200 Osborn Dr. , Room 251 Bessey , Ames, IA, 50011-4009, USA
2 - Universidade Estadual Paulista, Departamento de Botânica, Instituto de Biociências, Rio Claro, SP, 13506-900, Brazil
3 - Iowa State University, 2220 Osborn Dr., Room 251 Bessey Hall, Ames, IA, 50011-4009, United States

Keywords:
Chusqueinae
leaf anatomy
morphology
Woody bamboos.

Presentation Type: Oral Paper
Session: 45, Monocots part B/Basal Eudicots
Location: 200/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 3:00 PM
Number: 45007
Abstract ID:299
Candidate for Awards:None