BOTANICAL MUSEUM LEAFLETS VoL. 26, No. | 
JANUARY 31, 1978 
REVISION OF THE GENUS MASDEVALLIA - I. 
HERMAN R. SWEET 
The members of the genus Masdevallia have been in con- 
stant demand during recent years. The genus is comprised of 
some 400 species, most of which are poorly known, and those 
in cultivation frequently misidentified. Several years ago I 
started a complete revision of the genus, and this paper is the 
first step towards its finalization. 
In 1925 Kranzlin published a monograph of the genus Mas- 
devallia which in reality was an updated version of THE GENUS 
MASDEVALLIA by Miss Florence H. Woolward, originally pub- 
lished in 1896. The best part of Kranzlin’s monograph is his 
principal division of the genus into 14 sections. Here Kranzlin 
demonstrated again, just as he had done with the genus On- 
cidium, his ability to recognize natural groups. At the same 
time he raised havoc with the assignment of individual species 
into sections, a pattern quite uniform in all of his monographic 
studies. 
The first section taken up in this series 1s Triotosiphon pro- 
posed by Schlechter in 1922, but overlooked by Kranzlin. It 
was chosen purposely for it clearly reflects the taxonomic 
status of the genus as a whole. Some of the species now 
assigned to this section have been transferred to the genus 
Physosiphon. Admittedly, the technical distinction between 
Masdevallia and Physosiphon rests primarily in the calliferous 
petals in Masdevallia; this particular character also dif- 
ferentiates Masdevallia from the other genera of Pleurothal- 
lidinae. 
Because of the great similarity in gross morphology that 
often exists among species belonging to the same section, it 
became mandatory to dissect and draw every type specimen in 
order to understand the true characters of their morphology. 
When Schlechter chose the sectional name Triotosiphon — 
translated as a tube having three ears — he emphasized the 
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