Myoxanthus melittanthus (Schltr.) Luer (1982a: 47)

Rojas-Alvarado, Gustavo, Blanco, Mario A. & Karremans, Adam P., 2021, A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae), Phytotaxa 507 (3), pp. 211-258 : 241

27. Myoxanthus melittanthus (Schltr.) Luer (1982a: 47) (Fig. 15D)

Basionym: Pleurothallis melittantha Schlechter (1924: 49) .

TYPE:— COLOMBIA. Nariño: epiphytic, 10 km northwest of Pasto , Daza, 3000 m, Jan 1922 , Hopp 136 (holotype: B, destroyed, neotype here designated, Luer et al. 3023, SEL-021582!; isoneotype, SEL-021538!, illustrated in Luer (1982: Fig. 8 ; 1992: pl. 22). COLOMBIA. Cauca: Páramo de Barbilla , 3070 m, 27 Jul 1978.

Distribution: — Colombia and Venezuela.

Notes:— Myoxanthus melittanthus is similar to M.hystrix , but the former differs mainly in petals and column shape. Those of M. melittanthus are transversally rhomboid in the lower third with rounded margins, then contracted forming a slender tail with a slightly clavate tip, generally upwardly oriented, whereas those of M. hystrix are subcuadrate in the basal half with the margins obtusely angle, then contracted but terete into a yellow apex with a clavate tip downward oriented. The column wings of M. melittanthus are broader, not lobulate, extending from the base to the apex of the column, whereas in M. hystrix the wings are lobulate and rounded, emerging from near the middle to the apex of the column.

The holotype of this species was probably destroyed during the WWII. A neotype is designated here based on a collection by Luer near the type locality because no material associated with the protologue has been found. Carnevali and Ramírez (1988 –1989) mentioned that Venezuelan plants of M. melittanthus differ from those in Colombia in their slightly smaller flowers and glabrescent sepals that are verruculose adaxially .

Figures

FIGURE 8. Types of coflorescences in Pleurothallidinae. A. Single-flowered coflorescence type. B. Multi-flowered coflorescence type with simultaneous flowers and long flowering axis. C. Multi-flowered coflorescence with successive flowers and long flowering axis. D. Multi-flowered coflorescence with successive flowers and short flowering axis. Peduncle = red line, indicated by an arrow.Pseudopeduncle = discontinuous line. Black arrows = remain of the axis. Circles = flowers.