The systematics of Deprea raf. and Larnax (Miers) Hunz. (Solanaceae)

Date of Completion

January 1999

Keywords

Biology, Botany

Degree

Ph.D.

Abstract

A priori determinations of specimens of similar species were subjected to discriminant analyses using quantitative data. Results showed that all species, although quite variable and similar morphologically, were taxonomically distinct. Based on findings from this study, D. granulosa was relegated to synonymy with D. orinocensis, and the new combination, D. bitteriana, was erected. Field-based morphological investigation of Deprea and Larnax delimited 27 species. Seventy-six characters were scored for phylogenetic analysis at the genus- or species-level. Cladistic analyses using morphology of 13 genera with Datura as outgroup, species of Deprea and Larnax with Saracha and Vassobia as outgroups, analysis of nrDNA (ITS-2) sequence data, combined analysis of morphological and nuclear molecular data, and analysis of cpDNA (trnL intron) sequence data supplied evidence that (1) Deprea is distinct from a monophyletic Larnax that includes D. glabra and D. sylvarum ; (2) Saracha and Vassobia are sister genera to Deprea and Larnax; (3) lack of support for a physaloid clade with neither Physalis nor Withania closely related to Deprea or Larnax; and (4) support for the transfer of L. hunzikeriana to Cuatresia. Results indicate that corolla, filament, anther, and pollen characters support the separation of the genera. Analysis of historical biogeography suggests a Bolivian origin and subsequent northern radiations, Deprea largely into Colombia, Ecuador, and Venezuela; Larnax largely into Perú. High rates of sympatry and endemism suggest dispersal and subsequent isolation as the primary mode of speciation. Study of herbarium material of D. paneroi, revealed gender-based morphological distinctions that served to divide collections into male and female morphs, prompting field-based reproductive studies in Venezuela. Equal numbers exhibited female or male characteristics: either plants bore fruit and corollas with small, sterile anthers (females) or lacked fruit but produced pollen in large anthers (males). The morphology, receptivity, and developmental phenology of pistils were identical in both forms. Crossing studies revealed that the ovaries of open pollinated female flowers and female x male hand pollinations significantly enlarged and that male ovaries did not. Results strongly suggest the presence of cryptic dioecy in D. paneroi. A revision is provided with five new species described. ^

Link to Full Text

Share

COinS