Myoxanthus pennellius (Luer) Rojas-Alv. & Karremans

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 : 244-247

38. Myoxanthus pennellius (Luer) Rojas-Alv. & Karremans , comb. nov. (Fig. 17E)

Basionym: Pleurothallis pennellia Luer (1976b: 160–161) .

TYPE:— ECUADOR. Pastaza: epiphytic in felled trees about 20 km east of Puyo , ca. 600 m, 28 Jul 1975, Luer et al. 687 (holotype: SELspirit; illustration in Luer 1976b as f. 183!) .

FIGURE 17. Myoxanthus species. A . M. panamense . B – C. M. parahybuensis . D. M. parvilabius . E. M. pennellius . F. M. priapus . G. M. pulvinatus . H – J. M. punctatus . K – L. M. reymondii . Photographs by: L. Nauheimer ( A). G. Rojas-Alvarado ( B, C). S. Moreno (D). A. Hirtz ( E). Y. Dewèvre ( F). M. Rosim ( G). J. Gastin ( H). R. Stalder ( I). L. F. Varella ( J). R. Parsons ( K). J. Riksen ( L).

Distribution: — Ecuador and perhaps Peru (see below).

Notes:— Pleurothallis pennellia was described from Ecuador on the basis of a specimen that flowered in cultivation at the Marie Selby Botanical Gardens ( Luer 1976b). Luer compared it with M. scandens , but described it as having a much less prolific plant. The plant that served as type of P. pennellia eventually became prolific in cultivation, just like specimens of M. scandens , prompting Luer (1992) to place it under the synonymy of that species ( Luer 1992). However, based on the original description and illustration of the type, even with the prolific habit, M. pennellius is still easily distinguished from M. scandens . It differs from M. scandens in its sepals with an obtuse to rounded apex vs. acute, narrowly ovate petals slightly contracted above the middle, vs. wider basally then conspicuously contracted into a thickened apex and a lip with two longitudinal lamellae above the middle vs. with two longitudinal lamellae from the base to near the apex, a short clinandrium vs. long-hooded. None of the specimens of M. scandens studied here shares any of these features. We agree with Pupulin et al. (2010) that the photo of a Peruvian plant labelled M. scandens in Zelenko & Bermúdez (2008) fits the description of M. pennellius .