Acianthera sect. Antilla (Luer) A.Doucette, 2016

Doucette, Alfonso, Timyan, Joel, Henrys, Ingrid & Cameron, Kenneth M., 2016, A tiny new species of Specklinia from Haiti’s Parc National Naturel Macaya and new combinations in Acianthera (Pleurothallidinae, Epidendreae, Epidendroideae, Orchidaceae), Phytotaxa 275 (3), pp. 263-276 : 269

1. Acianthera sect. Antilla (Luer) A.Doucette , comb. et stat. nov.

Basionym: Pleurothallis subgenus Antilla Luer (2000: 39) . Type: Pleurothallis trichophora Lindley (1858: 326) . Antilla (Luer) Luer (2004: 255) .

Acianthera sect. Antilla includes species endemic to the Caribbean. The species were previously attributed to the genus Pleurothallis , however, molecular evidence presented here ( Fig. 1 , Table 1) and by Stenzel (2004) shows they do not form a monophyletic group, and that they are in fact embedded within Acianthera . Acianthera sect. Antilla species are rare in cultivation and there are no registered hybrids ( The International Orchid Register 2016). Thus, the proposed name changes will have a limited impact on the horticultural community.

The vegetative morphology is similar to that of other sections of Acianthera , but the margins of some species are denticulate. The inflorescences are a solitary flower or a successively or simultaneously flowered raceme. The lateral sepals are fused for their length and free from the dorsal sepal in all species except Acianthera alainii . Pleurothallis caymanensis Adams (1971: 146) and Pleurothallis spilo-porphoreus Dod (1978: 57) have ambiguous morphology (reduced stems and solitary flowered inflorescences) shared by other genera also present in the Caribbean, however, the two may also belong to this section and should be including in future phylogenetic analyses in order to confirm. Pleurothallis neibana Dod (1984b: 101) is listed by The Plant List (2012) as a heterotypic synonym of P. spilo-porphoreus , however, the two differ in the floral morphology and it may represent another species requiring transfer to the section should the two be considered distinct species. This section is maintained with the same 12 components previously assigned to Antilla and one additional species, Acianthera simplicifolia .

Figures

FIGURE 1. Phylogenetic reconstruction of Caribbean Pleurothallidinae based on ML analysis of nrITS data. ML Bootstrap values greater than 70% indicated at the nodes. The position of Acianthera bissei in 50:108 trees from the un-pruned bootstrap analysis is indicated by the dotted line. Specklinia lichenicola is based on an individual that matches the synonymous Pleurothallis gemina (Luer 2006; The Plant List 2012) in morphology; see notes under Specklinia macayensis for a complete discussion of the taxonomy.