34 



formed by the junction of the columnar foot and labellar claw. 



When the flower is about to expand the lateral sepals 

 separate and suddenly rotate on their bases, so as to take up a 

 position on the opposite side of the ovary, with their convex 

 surfaces now facing each other ; the dorsal sepal also retracts a 

 little from the column ; the columnar processes relax their grip 

 of the lamina, and the labellum suddenly flies out with the 

 claw at right angles to the columnar foot. 



Baron von Mueller mentions that "Mr. Bauerlin noticed 

 in D. Huntiana, that at the slightest touch the labellum 

 snatches across to the anther and stigma, subsequently return- 

 ing with slowness to its remote positions." 



Through the kindness of Mr. A. B. Braine, who supplied 

 me with fresh specimens of this plant, I was able to closely 

 observe the mechanism of expansion, but never on any occasion 

 did I find the labellum. irritable. I understand, too, that Mr. 

 Braine, who was able to study them under more natural 

 conditions, also failed to observe irritability. So remarkable a 

 conformation is exceedingly suggestive of this peculiarity, and 

 it is. possible that irritable movements are only displayed under 

 certain meteorological conditions. 



This singular and rare little orchid was first recorded from 

 Mount Tingi Ringy (4,700 feet), and later at Blackheath(L. H. 

 Stephenson), in the Blue Mountains. It has not hitherto been 

 recorded from any other locality. The present plants have 

 reached me from Cravensville, near Tallangatta, in Victoria, 

 and were collected by Mr. A. B. Braine in December, 1917. 



The genus Drakea contains 5 known species, two of which, 

 D. irrltabilis, Reich., and D. Huntiana, F. v. M., are natives 

 of Eastern Australia ; the others, D. elastica, Lindl., D. glypto- 

 don, Fitz., and D. ciliata, Reich., come from Western 

 Australia. 



Differential Table. 



Labellum articulated directly by its claw to 

 column without intervening basal pro- 

 jection; lanceolate or ovate-lanceolate 

 leaf at time of flowering. 

 Leaf-like bract on stem ; column not 



reflexed on ovary T). ciliata 



Labellum articulated at end of basal pro- 

 jection of column. 

 Leafless at time of flowering. 



Dorsal sepal greatly exceeding other seg- 

 ments of perianth, column reflexed 



at right angles with ovary D. irritabilis 



Segments of perianth about equal in 

 length ; column actually reflexed on 



ovary D. Huntiana 



Leaf present at time of flowering; rigid, 

 orbicular or ovate-cordate. 



