The Guiana Orchids. 28^5 



from which one species, not native^ has received the 

 name of Dove Orchis. Three species : — 



1. P. cerina ... Flowers yellow. 



2. P. pendula ... Flowers white, spotted with lilac. 



3. P. selligera ... Similar to the last but with slight differ- 



ences in the shape of the lip and 



column. 

 14. Catasetum. — This is perhaps the most interesting 

 genus in the whole order to the botanist, as several 

 species have apparently the power of producing different 

 shapes and sexes of flowers according to circumstances. 

 The typical form of flower has a pouch or hood-like 

 lip, widening in front, and placed upside down as it were, 

 with the column below instead of above as in most 

 orchids. This, the female, is common to most of 

 the species and probably to all, although it has not 

 yet been recorded from more than about half. In 

 the case of Catasetum macrocarpum this form was, when 

 discovered, made the type of the genus Monachanthus 

 and named M. viridis. It is borne upon shorter flower- 

 stems than the other forms and in the forest is often 

 found bearing numbers of its very large capsules. The 

 second form is doubtful as to sex but is probably male, 

 and in the species in question was named C. tridentatum. 

 It may be compared in shape to a sun-bonnet and is 

 more showy than the Monachanthus. Finally we have 

 the Myanthus form, originally put in a separate genus 

 under the name of M. barbatus. This is distin6lly male 

 and its lip is flat, fringed, and in Its normal position. 

 When out of flower the species are hardly recognisable 

 from each other, all having fleshy cylindrical pseudo- 

 bulbs with a double rank of leaves. Even the temale 

 flowers closely resemble each other and it is therefore 



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