Myoxanthus congestus (A.Rich. & Galeotti) Soto Arenas 2008 SUBGENUS Myoxanthus SECTION Myoxanthus Luer 1992

Photo by JM VP The Orquideas Mexicanas Website

Plant and Flowers

Photo by Patricia Harding


Drawing by Carl Luer

Common Name The Congested Myoxanthus

Flower Size .4" [1 cm]

Found from Mexico, Guatemala, Nicaragua, Coasta Rica, Panama, Venezuela and Guyanas in forested ravines at elevations of 200 to 1300 meters as a small sized, hot to cool growing epiphyte and occasional lithophyte with stout, erect, ramicauls enveloped basally by 5 to 6, tubular, hispidous sheaths and carrying a single apical, erect, thickly coriaceous, elliptical to narrowly elliptical, acute to subacute leaf that is cuneate below into a conduplicate, subpetiolate base and blooms in the fall on a fascile of single, successive flowers, producing from 1 to 20 simultaneously at the apex of the ramicaul with sparsly pubescent, shorter than the ovary floral bracts.

"This species is morphologically similar to M. cereus, M. octomerioides and M. pulvinatus. From M. cereus, M. congestus is distinguished by the narrow elliptic leaves vs. broad elliptic to ovate, ovate petals vs. oblong, scarcely adaxially verrucose lip with angled margins vs. oblong and conspicuously verrucose. From M. octomerioides, it is distinguished by the yellowish whitish perianth vs. perianth suffused with pink to purple. From M. pulvinatus and M. congestus, it differs in the column with aciculate teeth on each side and acute to obtuse lip vs. triangular, frequently bidentate on each side and generally apiculate lip. When Soto Arenas revised the Mexican Myoxanthus, he noted that the original material of P. congesta fitted the concept of M. octomeriae better than that of M. octomerioides as previously stated by Luer (1982a, 1992; see RojasAlvarado & Karremans 2020." Rojas-Alvarado, Blanco and Karremans 2021

Synonyms Myoxanthus octomeriae (Schltr.) Luer 1982; Myoxanthus octomerioides var. octomeriae (Schltr.) O.Gruss & M.Wolff 2007; *Pleurothallis congesta A.Rich. & Galeotti 1845; Pleurothallis octomeriae Schltr. 1922; Pleurothallis ramentacea Garay & Dunst. 1976

References W3 Tropicos, Kew Monocot list , IPNI

Repert. Sp. Nov. Regni. Veg. Beih. 17: 21. Panama Schlechter 1922 as Pleurothallis octomeriae;

The Orchids of Panama L.O. Williams & P Allen 1946 as Pleurothallis octomeriae;

Venezuelan Orchids Illustrated Vol 6 Dunsterville & Garay 1976 as Pleurothallis ramentacea drawing fide;

Orchids of Venezuela An Illustrated Field Guide Vol 3 Dunsterville & Garay 1979 as Pleurothallis racementacea drawing fide;

Icones Planetarum Tropicarum plate 879 Dodson 1983 as M octomeriae drawing hmm;

Icones Pleurothallidinarum Vol IX Systematics of Myoxanthus Luer 1992 as M octomeriae drawing fide;

Guatemala Y Sus Orquideas Behar & Tinschert 1998 photo not! = M exasperatus

Orchids of Venezuela [An illustrated field guide] Vol. 2 Ramiro and Carnevali 2000 drawing fide;

Manual de Plantas de Costa Rica Vol 3 Hammel, Grayum, Herrera and Zamora 2003 as M octomeriae;

*Icones Orchidacearum 10 Plate 1053 Hagsater & Soto 2008 drawing fide;

Orchid Genera and Species in Guatemala Archila, Szlachchetko, Chiron, Lipinska, Mystkowska and Bertolini 2018;

Vanishing Beauty, Native Costa Rican Orchids Vol 2 Lacaena to Pteroglossa Pupulin 2020 photo fide;

Pleurothallids Neotropical Jewels Vol 1 Karremans & Viera 2020 photo fide;

A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae) Gustavo Rojas-Alvarado, Mario A. Blanco, A. P. Karremans 2021 photo fide