TAXONOMIC REVISION OF THE SECTION HETEROTAXIS FROM THE GENUS MAXILLARIA

A revision of the section Heterotaxis (Lindl.) Brieg., subgenus Aggregatae (Pfitz.) Brieg., genus Maxillaria Ruiz et Pavon is presented. The section, with a total of 10 spp., can be divided into 2 groups. The 1st group, with smaller flowers (sepal length from 15-20 mm), contains the following species: M. crassifolia (Lindl.) Rchb. f., distributed mainly in Central America with some penetration into Colombia and Venezuela; M. brasiliensis Brieg. et Illg, distributed along the mountain regions of the Brazilian Atlantic Coast from Rio Grande do Sul to Bahia; M. tarumaensis Hoehne, from the Lower Amazon Basin; M. superflua Rchb. f. from the Lower Amazon Basin and Guianas; M. villosa Barb. Rodr., which occupies a large area from Colombia to Venezuela, through the Amazon Basin to Pernambuco (Brazil); M. discolor (Lodd.) Rchb. f. occupies a rather discontinuous area in the southern part of Venezuela and Para (Brazil), south of Bahia and in the State of Sao Paulo, in the coastal region of Ubatuba. It was concluded that there is no difference between M. proboscidea Rchb. f. and M. nasuta Rchb. f.; the latter name is a synonym of the former. M. proboscidea has long flower peduncules with well spaced bracts; M. brevipedunculata has very short peduncles with strongly imbricated bracts. M. violaceopunctata Rchb. f. from the Amazon Basin and Guianas varies considerably in the size of the flowers; M. maleolens Schltr. is so far known only from Costa Rica and Panama. Short measurements of all 10 spp. are given, and the differences are explained in a key.