ISSN:
1615-6110
Keywords:
Angiosperms
;
Rubiaceae
;
Tocoyena
;
Hybridization
;
differentiation
;
speciation
;
homogamic complex
;
tropical woody plants
;
taxonomy
;
Flora of South America
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The variation pattern of a large population ofTocoyena formosa in Botucatu, state of São Paulo, Brazil, and of other samples throughout the species area was analysed by morphometrical, statistical, ecological, and phytogeographical methods. Excessive variation and the remarkable coherence of two different character syndromes within this species strongly suggest that it has originated as a homogamic (diploid) hybrid complex. Possible parental species areT. brasiliensis, mainly from the Amazon region, andT. viscidula from the dry caatinga region of NE. Brazil.T. formosa has a much more extensive geographical range and greater ecological plasticity, ranging from the Amazon basin and the Guyanas throughout the Central Brazilian Plateau and from NE. to S. Brazil and Paraguay. Three (partly sympatric) varieties are distinguished withinT. formosa, i.e. var.formosa, var.pseudobrasiliensis (var. nov.), and var.microdon (comb. et stat. nov.). A provisional taxonomic revision, key, and conspectus covers the 12 accepted species ofTocoyena with blunt flower buds and ovate obtuse corolla lobes (group A, includingT. formosa); their distribution is shown in a map.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00937441
