ORCHIDACE^ 



naturUchen Pflanzenfamilien, Dendrochilum proper (§Eudendro- 

 chilum), distinguished from Platyclinis by a lateral inflorescence 

 and leaves duplicative in the bud, was placed in the Bolbophyl- 

 linas, fifty-two pages distant from the Coelogyninas, in which 

 Platyclinis was placed. In 1907 Pfitzer and Kranzlin, in accor- 

 dance with the views of J. J. Smith, combined Dendrochilum 

 and Platyclinis, making Platyclinis a subgenus of the former. 

 This radical change proves conclusively that vegetative varia- 

 tions may arise which disturb materially a system of classification 

 based almost exclusively upon vegetative parts. Furthermore, 

 the results are annoying if morphological exceptions occur when 

 vegetative characteristics are employed in casting large groups. 



Notwithstanding the opinions held by Pfitzer regarding the 

 advisableness of placing more reliance on vegetative than on 

 floral structures in the classification and arrangement of the 

 Orchidacese, the genus Dendrochilum, in my judgment, may be 

 more naturally subdivided if the species are grouped into sub- 

 genera, or sections, according to the peculiarities of the gynoste- 

 mium. This system has one difficulty, namely, the necessity of 

 examining minute details, which may be thought too great for 

 convenience ; but as a knowledge of the species of Dendrochilum 

 is only to be had after careful analysis of the flowers, this incon- 

 venience is not so great as at first it may seem to be. 



§ Acoridium is clearly set off from § Platyclinis and §Euden- 

 drochilum by the absence from the gynostemium of stelidia. 

 §Eudendrochilum is distinguished from the other sections, or 

 subgenera, by its laterally produced flower shoot (which arises 

 from the base of a pseudobulb), alt hough agreeing with § Platy- 

 clinis in possessing stelidia. These three sections include without 

 undue violence to affinities all known species of Dendrochilum, 

 if we except the Philippine species described as Z). Woodi- 



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