OrchidecB. 133 



outer (sep.), 3 inner, of which 2 {petals) are alike, the third 

 {lip) is usually larger, dissimilar, often spurred; stam, and 

 style confluent in a column opp. the lip; anth. one, sessile on 

 the column (or in Apostasia anth. 2, one on each side of the 

 column) ; pollen grains cohering in each cell in i, 2, 4 or 8 waxy 

 or powdery masses (pollinia) ; ov. i -celled (3-celled in Apo- 

 stasia), usually narrow and twisted, stigma a viscid spot below 

 the anther, or of 2 processes (or terminating the styliform top 

 of the column in Apostasia) ; fr. a loculicidal capsule (rarely in- 

 dehiscent), the valves separating from three persistent ribs ; 

 seeds minute, testa lax, nucleus homogeneous. 



The third largest Order of flowering plants in number of species in 

 Ceylon, ranking between Graimnetz and Cyperacece ; and the third largest 

 also in number of genera. In percentage of endemic species it is the 

 fifth of all the larger Orders, nearly half the species being endemic. On 

 the other hand, it is remarkable for the paucity of endemic genera, of 

 which there are only three out of the whole number (6i). In the 

 arrangement of the genera, I have adhered as closely as I could to 

 the ' Genera Plantarum ' and ' Fl. Brit. Ind.' The principal deviation 

 from these works is the placing of Phreatia in VandecE, in which I am 

 supported by Dr. King. I have also restored two imperfectly known 

 genera of Thwaites, Octarrhena and Alvisia. By far the greater number 

 of species of Orchids have been described for this work from Herbarium 

 specimens solely, or, if aided by published or unpublished figures, these 

 are too often unaccompanied by good analyses. Consequently, not a 

 few of those descriptions will require rectification or amplification from 

 living specimens. An illustrated work on the Orchids of Ceylon, with 

 careful analyses, like Sir G. King's Orchids of the Sikkim Himalaya, 

 would be a great boon to botanists and amateurs. Of the i6o species 

 described in this work, only 97 have been figured, few of them from 

 Ceylon specimens, most in inaccessible works, and not a few very 

 imperfectly. 



Stam. I. 



Pollinia waxy; anth. operculate. 

 Pollinia free or adhering in pairs or fours 

 by a viscus. 

 Pollinia 4. 

 Sep. and pet. widely spreading, lip de- 

 flexed or decurved from the base. 

 Lip superior, column very short. 



L. equitant, fleshy , . . .1. Oberonia. 

 L. not equitant, membranous . 2. Microstylis. 

 Lip inferior, column long . . . 3. LiPARlS. 

 Sep. and pet. more or less connivent, 

 lip erect from the base. 

 Column prolonged into a foot. 



Lip not articulate on the foot . 4. Dendrobium. 

 Lip articulate on the foot. 

 Lateral sep. not much exceeding 



the dorsal . . . .5. BULBOPHYLLUM. 



