Systematics Section / ASPT
Judd, Walter S. , Penneys, Darin S. , Skean, James D. .
Systematic diversity of Miconia (Melastomataceae) on Hispaniola..
Our taxonomic studies indicate that 56 species of Miconia are known to occur on Hispaniola. Thirty-five of these belong to Miconia sect. Chaenopleura, a distinctive and diverse clade diagnosed by an actinomorphic androecium, obovate, usually white anthers that open by two longitudinal slit-like pores, and pale blue berries. Another six species are members of sect. Cremanium, a group characterized by anthers that open by a gaping apical pore that sometimes is extended, forming a broadly to narrowly V-shaped longitudinal slit, with the septum between the anther sacs clearly visible and usually protruding; the anthers also often have bilobed basal appendages. The anthers are the same color as the petals (frequently white) and, like those of sect. Chaenopleura, are arranged radially. Four of these species, i.e., M. desportesii, M. tetrastoma, M. monciona, and M. sphagnicola, share narrowly paniculate to racemose inflorescences, setose-serrate leaves, a distinctive indumentum, and twigs with two opposing faces slightly concave. They may be closely related. Miconia alloeotricha has recently been transfered from Ossaea; and M. tetrandra includes M. abeggii (a name based on a vigorous, vegetative shoot). The remaining 15 species are mainly widespread Neotropical taxa and belong to sects. Amblyarrhena (anthers short, opening by minute apical pore; 2 species), Tamonea (anthers elongate-ovate, curved, apically narrowed, opening by apical pore; 3 species), or Miconia (anthers linear, straight to curved, opening by apical pore; 10 species). The frequently confused M. laevigata and M. pyramidalis differ in inflorescence architecture, and are briefly contrasted. The greatest species diversity is reached in the Cordillera Central, Massif de la Selle, and Massif de la Hotte. Distributional patterns and speciation mechanisms are also discussed.
Melastomataceae of the World
1 - Albion College, Department of Biology, Albion, Michigan, 49224, USA
2 - University of Florida, Department of Botany, 220 Bartram Hall, P.O. Box 118526, Gainesville, Florida, 32611-8526, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 4:15 PM