refrained from giving names to the various divisions and 
subdivisions as I do not feel that our knowledge of the 
genus and its nearest allies is anything like complete. 
A. Column rather short, tapering upwards, androclinium rather small 
and sloping upwards; rostellum beak-like, deflexed, bilobed on 
removal of pollinarium, lobes subulate; stipites two attached to a 
common viscidium. 
a) Stems very short with a rosette of leaves or only slightly elon- 
gated; flowers alternate. 
1. D. pellucida (Lindl.) Schltr. 
2, D. bueae (Schltr.) Schltr. 
3. D. Plehniana (Schltr.) Schltr. 
4. D. Quintasii (Rolfe) Schltr. 
b) Stems elongated, leafy along a great deal of their length; flow- 
ers alternate. 
5. D. bidens (Sw. ex Pers.) Schltr. 
6. D. subclavata (Rolfe) Schltr. 
7. D. acuta (Ridl.) Schltr. 
8. D. papagayi (Reichb f.) Schltr. 
9. D. congolensis (De Wildem.) Summerh. 
10. D. divitiflora (Kraenzl.) Schltr. 
c) Stems long or short; flowers opposite or verticillate. 
11. D. fragrantissima (Reich. ) Schltr. 
12. D. Welwitschii (Reichb f.) Schltr. 
13. D. vandiformis (Kraensl.) Schltr. 
B. Column short and truncate, androclinium large, occupying the 
whole of the apex; rostellum porrect, trilobed on removal of pol- 
linaria, middle lobe fleshy, more or less spathulate, laterals shorter, 
triangular; stipites 2, each attached to a separate viscidium. 
a) Stems short or only slightly elongated. 
14. D. kamerunensis (Schltr.) Schltr. 
15. D. curvata (Rolfe) Summerh. 
16. D. polydactyla (Kraenzl.) Summerh. 
17. D. Mildbraedii (Kraensl.) Schltr. 
18. D. tenerrima (Kraenzl.) Summerh. 
19. D. pulchella Summerh. 
20. D. ugandensis (Rendle) Summerh. 
b) Stems much elongated. 
21. D. Stolzii Schltr. 
22. D. Schimperiana (4. Rich.) Summerh. 
23. D. tenuicalear Summerh. 
24. D. subsimplex Summerh. 
The column in group B is almost identical with that 
in the genera Rhipidoglossum Schltr. and Sarcorhynchus 
Schltr., but in many other features the various species 
may resemble closely species in group A. The charac- 
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