PhytoKeys (Sep 2011)
Spigelia genuflexa (Loganiaceae), a new geocarpic species from northeastern Bahia, Brazil
Abstract
A new species of Spigelia (Loganiaceae) from Bahia (Brazil) is described, being the first reported geocarpic species in the family. During fruit maturation, the more basal infructescences bend down towards the ground, depositing the fruit on the surface, whereas the upper ones do so slightly but noticeably. The species is a short-lived annual apparently restricted to sandy-soil habitat with variable and heterogeneous microenvironment and is known from only two restricted localities. A short review of amphi- and geocarpic species is provided. A discussion of comparative morphology within Spigelia with regards to dwarfism, indumentum, and annual habit is included. A phylogenetic parsimony and Bayesian analysis of ITS sequences from 15 Spigelia species plus 17 outgroups in Loganiaceae confirms its independent taxonomic status: on the basis of sequence similarity and phylogenetic topology it is phylogenetically distinct from all Spigelia species sequenced so far.