NOTES ON ERYTHRODES 



AVITH NOMENCLATORIAL CHANGES AND DESCRIPTIONS OF 



THREE NEW SPECIES 



The genus Erythrodes founded by Blume and regarded as syn- 

 onymous with Physurus L. C. Rich, has been reestabhshed as a 

 living name by Fawcett and Rendle because Physurus as pub- 

 lished by L. C. Richard is a novien nudum?- 



Dr. Rudolf Schlechter in his studies of the group to which 

 Erythrodes belongs concluded that the palaeotropical species are 

 clearly distinguished from the neotropical by a bilobed or didy- 

 mous sac on the labellum. He proposed that Blume's Erythro- 

 des should be restricted to the palaeotropical species, the neotrop- 

 ical species being set apart as a distinct genus under Physurus. 



Fawcett and Rendle in their discussion of the value of a bi- 

 lobed sac for generic characterization put Schlechter's conclu- 

 sions aside as in their judgment a bilobed sac is of trivial im- 

 portance for the separation of the species of this group into dis- 

 tinct genera, and they directed attention to the occasional occur- 

 rence of a bilobed sac in the West Indian Erythrodes plant aginea 

 Fawc. & Rendle. 



Surely a bilobed sac by itself is a very superficial character for 

 purposes of classification and should be disregarded in the defini- 

 tion of genera, unless correlated with other substantial differ- 

 ences. It is a character that is capable of extreme variation in 

 species that exhibit it and may occur as a manifestation of abnor- 

 mal development in a species which is normally without it. In 

 other words, it is a character that may come and go and is plastic 

 under those influences that govern the production of teratological 

 formations in the orchid flower. Furthermore, the bilobed sac is 



1 Flora of Jamaica 1 (1910) 28. 



[63] 



