aBstract. In this paper we summarize the taxonomic history of Pleurothallis crocodiliceps Rchb.f. and demonstrate that the species described by Reichenbach did not possess the stereotypical minute, pubescent, tri-lobed lip, with basal lobes modified into "horns". The first two species described with such a lip were P. arietina and P. nelsonii. Rather than a single widely distributed, variable species, with a morphologically constant lip, P. crocodiliceps, we recognize the P. arietina-P. nelsonii species complex. Herein we describe four new species in this complex and discuss the morphological characters useful in distinguishing among the members of the complex. We also discuss the nature of the lip possessed by members of this complex and propose that it may mimic a female insect luring a male fly into pollinating the flower by pseudocopulation.

A new species of Acianthera from Brazil is described and illustrated here. The novelty belongs to the nominal subgenus of Acianthera and it resembles Acianthera hystrix and A. portilloi but it is easily distinguishable by the external and internal pubescence of the sepals, the pubescent ovary and the lip disc ornamented with three lamellae. A dichotomous key to identification of all known species of Apoda-prorepentia group is provided.

aBstract. Pleurothallis trimeroglossa has long been considered a synonym of P. talpinaria. In this study we reviewed types, descriptions, drawings, paintings and living material for both names and concluded that P. talpinaria and P. trimeroglossa should be recognized as distinct species. An anatomical structure important in the distinction between the two is the large dome-shaped callus at the base of the lip in P. trimeroglossa. The approximate distributions and elevational ranges of the two species are discussed. During the study we recognized a novel species, described here as Pleurothallis jostii. Labellar morphology of all three species was examined. We speculate on the pollination mechanism of this group of species based on the observations of labellar micro-morphology.