Rossado et al. 2026 (Article) Tillandsia, Diaphoranthema

Genomic and morphological evidence supports the segregation of two new species from Tillandsia myosura (T. subg. Diaphoranthema, Bromeliaceae)

Author(s):—A.J. Rossado, C.G. Mendoza, S. Donadío, S.I. Vera-Paz, D.D.D.C. Díaz, S. Wanke, G.A. Salazar, S. Magallón, M.H. Barfuss & J.M. Bonifacino

Corresponding email:—arossado@fcien.edu.uy

Publication:—Phytotaxa 756(1): 25-58. (2026) — DOI

Abstract:—Morphological and molecular evidence, including phylogeny and plastome structural features, together with the geographic distribution and phenological data, strongly support the recognition of three distinct lineages within the traditional circumscription of Tillandsia myosura, here named T. myosura s.str. and two newly described species, T. cleistopetala and T. pachyphylla. Tillandsia myosura is redefined as a morphologically and ecologically narrower species endemic to Argentina (from the northwest to the central region), and closely related to T. andicola and T. retorta. Tillandsia cleistopetala sp. nov. instead occurs in Uruguay and central-eastern Argentina, showing an allopatric and ecologically distinct distribution compared to T. myosura s.str. Tillandsia cleistopetala sp. nov. is sister to T. crocata and is reproductively characterized by consistently cleistogamous flowers. Tillandsia pachyphylla sp. nov. is morphologically well differentiated from T. myosura s.str. by several vegetative and reproductive characters. Tillandsia myosura s.str. and T. pachyphylla sp. nov. are partially sympatric but are phenologically differentiated. Tillandsia pachyphylla sp. nov. is distributed in central Bolivia and from northwestern to central Argentina and is part of a clade that includes T. castellanii, T. hirta, and T. mandonii. A taxonomic treatment of the two new species and T. myosura s.str. is presented, including detailed morphological descriptions, information on geographical distribution, habitat, phenology, and conservation status, along with representative photographs and illustrations of floral parts. A lectotype for Tillandsia nappii is designated.

Keywords:—cleistogamy, epiphyte, Myosura group, plastid genome, Southern Cone, Tillandsioideae

Published names (2):

Tillandsia cleistopetala
Tillandsia pachyphylla

Taxonomy:—Tillandsia hirta New position within Diaphoranthema, more closely related to Tillandsia castellanii L.B. Sm. (formerly 14-226.1) (p.33).—Tillandsia mandonii New position within Diaphoranthema, more closely related to Tillandsia castellanii L.B. Sm. (p.33).—Tillandsia myosura Morphological and molecular evidence, including phylogeny and plastome structural features, together with the geographic distribution and phenological data, strongly support the recognition of three distinct lineages within the traditional circumscription of Tillandsia myosura, here named T. myosura s.str. and two newly described species, T. cleistopetala and T. pachyphylla. (p.27).—Tillandsia nappii Lectotype designated: Lorentz 122 (BM, isolectotypes: F, G, LE, M, NY, P, W, WU (p.36).