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| Tanaecium decorticans Frazão & L.G.Lohmann, in Frazão & Lohmann, 2018. |
Abstract
Tanaecium (Bignonieae, Bignoniaceae) is a genus of Neotropical lianas that is centered in the Amazon. The genus exhibits interesting patterns of morphological variation, especially in terms of flower morphology. Despite that, the group remains poorly known, lacks a phylogeny and a taxonomic revision. While working on the systematics of Tanaecium, we encountered a morphological variant of Tanaecium pyramidatum from the Brazilian Amazon that represents an independent evolutionary lineage and differs from that species in various morphological traits. This taxon is here described as Tanaecium decorticans, sp. nov. While T. decorticans is sister and most morphologically similar to T. pyramidatum, it differs in the peeling epidermis (vs. not peeling in T. pyramidatum), presence of an arrow-shaped petiolule (vs. absence of an arrow-shaped petiolule in T. pyramidatum), and interpetiolar region covered with fields of glandular trichomes (vs. aglandular interpetiolar region in T. pyramidatum), among other characters. This finding highlights the importance of in-depth taxonomic studies of individual lineages for an improved understanding of the Amazonian biodiversity.
Keywords: Amazonia, Lianas, Neotropical biodiversity, Taxonomy
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| Tanaecium decorticans Frazão & L.G.Lohmann. a flowering branch; b detail of node; c detail of peeling epidermis; d detail of arrow-shaped apex of petiolule at the adaxial surface; e detail of arrow-shaped apex of petiolule at the abaxial surface; f flower in pre-anthesis; g detail of calyx; h detail of calyx apex and glandular trichomes; i detail of corolla showing stamen insertion; j nectar disk, ovary, style, and stigma; k detail of ovary trichomes; l fruit; m detail of fruit trichomes along the margin. Illustrated from Frazão et al. 210 (SPF) |
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| Key morphological features of Tanaecium decorticans Frazão & L.G.Lohmann. a flowering branch; b side view of flowers; c flower buds showing the acute apices. White arrow indicates the patelliform glandular trichomes found in the calyx; d branch with peeling epidermis. White arrow indicates the arrow-shaped petiolule apex, while black arrow indicates the subulate prophylls of the axillary buds. Photos: A. Frazão |
Tanaecium decorticans Frazão & L.G.Lohmann, sp. nov.
Etymology: The species epithet refers to the stem with peeling epidermis.
Annelise Frazão and Lúcia G. Lohmann. 2018. A New Species of Tanaecium (Bignonieae, Bignoniaceae) from the Brazilian Amazon and Its Phylogenetic Placement. Plant Systematics and Evolution. 304; 1245–1253. DOI: 10.1007/s00606-018-1544-x [05 October 2018]
