A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae) Author Rojas-Alvarado, Gustavo 0000-0002-8918-0823 Jardín Botánico Lankester, Universidad de Costa Rica, Cartago, Apartado 302 - 7050, Costa Rica & gustavo. rojasalvarado @ uc. ac. cr; https: // orcid. org / 0000 - 0002 - 8918 - 0823 gustavo.rojasalvarado@uc.ac.cr Author Blanco, Mario A. 0000-0001-7369-5411 Jardín Botánico Lankester, Universidad de Costa Rica, Cartago, Apartado 302 - 7050, Costa Rica & Centro de Investigación en Biodiversidad y Ecología Tropical, Universidad de Costa Rica, Apdo. 11501 - 2060 San José, Costa Rica & Escuela de Biología, Universidad de Costa Rica, Apdo. 11501 - 2060 San José, Costa Rica & mario. blancocoto @ ucr. ac. cr; https: // orcid. org / 0000 - 0001 - 7369 - 5411 mario.blancocoto@ucr.ac.cr Author Karremans, Adam P. 0000-0001-5987-7710 Jardín Botánico Lankester, Universidad de Costa Rica, Cartago, Apartado 302 - 7050, Costa Rica & Naturalis Biodiversity Center, Endless Forms, Sylviusweg 72, Leiden 2333 BE, The Netherlands & akarremans @ gmail. com; https: // orcid. org / 0000 - 0001 - 5987 - 7710 akarremans@gmail.com text Phytotaxa 2021 2021-06-10 507 3 211 258 http://dx.doi.org/10.11646/phytotaxa.507.3.1 journal article 10.11646/phytotaxa.507.3.1 1179-3163 5425729 39. Myoxanthus priapus Luer (1983a: 386) . (Fig. 17F) TYPE :— ECUADOR . Loja : epiphytic in cloud forest east of Yangana , Altos de Numbala , 2800-2900 m , Jun 1982 , D’Alessandro 195 ( holotype : SEL !). Distribution:Ecuador and Peru . Notes:— Myoxanthus priapus is similar to M. ortizianus with which it shares the purple-yellowish flowers covered abaxially by short trichomes with the lateral sepals forming a suborbicular synsepal and petals yellowish purple stripped, obovate to oblong basally, then contracted and lip with a thick erect callus near the base. It can be distinguished by the basal half of the petals oblong to obovate then narrow vs . apex of the petals narrower forming a slender tail and an oblong lip with small acute lateral lobes near the middle vs . lip weakly trilobed with rounded lateral lobes below the middle.