A clarification of the taxonomy of Pleurothallis crocodiliceps (Pleurothallidinae, Orchidaceae) and four new species of Pleurothallis in subgenus Ancipitia

Abstract

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 Pleurothallis (Orchidaceae: Pleurothallidinae) in subsection Macrophyllae-Fasciculatae with a unique, highly reduced, morphologically distinct labellum

“…Interestingly, the papilla-lined cavity of P. minutilabia strongly resembles the cavity in the lips of the P. crocodiliceps complex (Fig. 15) (Wilson et al 2017a(Wilson et al , 2017b(Wilson et al , 2018, which are also hypothesized to involve deceitpollination by pseudocopulation. Acknowledging that only in situ observations of the pollination process can conclusively demonstrate deceitpollination by pseudocopulation in P. minutilabia, given the difficulty of performing such studies in a sparsely distributed, tropical montane species, in the meantime additional studies are planned to address the hypothesis.…”

“…remained the only known Pleurothallis species with a minute, highly reduced and apparently vestigial lip, none existing in any of the other taxonomic groups within Pleurothallis sensu Pridgeon et al (2005). The only thing remotely comparable being the very small, highly modified lips of the P. crocodiliceps species complex of subgenus Ancipitia (Wilson et al 2017a(Wilson et al , 2017b(Wilson et al , 2018. However, in 2015 an undescribed species of Pleurothallis was collected from Podocarpus National Park during an intensive survey of poorly collected areas of Ecuador (Muchhala & Pérez 2015, Pérez et al 2016, Orozco et al 2017.…”