Tubella (Luer) Archila (2000: 46)

Bogarín, Diego, Karremans, Adam P. & Fernández, Melania, 2018, Genus-level taxonomical changes in the Lepanthes affinity (Orchidaceae, Pleurothallidinae), Phytotaxa 340 (2), pp. 128-136 : 133

Tubella (Luer) Archila (2000: 46) . Basionym: Trichosalpinx subgen. Tubella ( Luer 1986: 66) . Type: Pleurothallis acremona Luer (1979: 157).

Synonym.: Trichosalpinx subgen. Tubella sect. Tubellae Luer (1986: 68) . Type: Pleurothallis acremona Luer (1979: 157) .

Synonym.: Pleurothallis sect. Acuminatae subsect. Lepanthiformes Lindley (1842: 72) . Type. Pleurothallis arbuscula Lindley (1842: 72) .

Comments:— Species of Tubella have a slender habit, commonly with proliferating ramicauls covered by lepanthiform sheaths, the inflorescence is longer than the leaf, the ovary is glabrous, the sepals membranaceous, glabrous, shortly acuminate, concave, the petals much shorter, entire, elliptic, the lip simple, commonly three-lobed, the base unguiculate, lacking lobules, the column elongated, apically winged, with a prominent column foot ( Fernández 2016). Species of Tubella are phylogenetically related to Anathallis from which they are separated by the slender habit, proliferating ramicauls with lepanthiform sheaths (vs. creeping or caespitose without proliferating ramicauls, and lacking the lepanthiform sheaths), and inflorescences longer than the leaves bearing several flowers (vs. inflorescences frequently shorter than the leaf and few-flowered). The flowers of Tubella are superficially similar to Gravendeelia , Stellamaris and Opilionanthe in the cupped flower with long caudate sepals and elongate column, however, they are not related phylogenetically.

Tubella is redefined from its previous circumscription by the exclusion of the species belonging to Gravendeelia , Opilionanthe , and Stellamaris , which are not closely related, and by the inclusion of the following six species: