Burchell, 5943 !, 8527 ! ; MacOwan d- Bolus, Herb. Norm. Aust.-Afr., 

 No. 177 ! 



Plate 89. The figure of the whole plant to the left shows the 

 average-sized one-flowered form ; that in the centre the rare and more 

 luxuriantly grown two-flowered form. Fig. 1, flower from a yellow 

 variety ; 2, vertical section through tbe middle of a flower, the apex of 

 the side sepal cut off; the colour boundary shows the line of junction of 

 the red petal with the green odd sepal ; 3, column with hp, viewed 

 obliquely from front and side ; 4, column only, front view ; 5, the 

 rostellum cut oft' at its junction with the ovary and reversed, showing 

 the pollinia in situ attached by their glands to the rostellary arms ; 6, tbe 

 anther with top of the ovary as it appears after removal of the covering 

 rostellum, the pollinia having been lifted out with the latter, viewed from 

 above; 7, cross section through the middle of the lip and clinandrium, 

 showing part of the lip above, below that the rostellum, next the pollinia 

 in situ, and lastly the anther cells and connective ; 8, one of the pollinia ; 

 9, ditto, as revolute in less than a second after withdrawal ; 10, lip, from 

 a form without dorsal appendage, — all variously magnified and from 

 several dift'erent flowers. 



An erect herb, from a span to a foot or more high ; stem 2-leaved, 

 straight or subflexuous, pilose towards the base, glabrous above ; leaves 

 remote erect-spreading lanceolate or linear-lanceolate acuminate, loosely 

 sheathing at base, 4-6 cm. long ; flower solitary, or very rarely 2 racemose, 

 bracts leaflike about as long as the ovary; side sepals spreading lauceolate 

 setaceo-acuminate, about 2 cm. long, obtusely saccate in the middle ; odd 

 sepal hooded, with a blunt sac at the apex behind, produced at front into 

 an erect filiform tubular acute appendage ; petals subrhomboidal concave 

 incurved, the angles rounded ; lip linear at base, widened and lanceolate 

 above, decurved or hooked at the apex, muticous or furnished behind with 

 a lanceolate or toothed appendage ; rostellum heart-shaped subobtuse, 

 with erect-spreading twisted arms at the base ; pollinia quickly revolute 

 after withdrawal. 



Described and drawn from living plants gathered near Cape Town. 

 Colour of the flowers variable : from a rosy purple which is darker on the 

 edges, to lilac ; there is also a form with yellow or greenish flowers. In 

 the latter the lip is usually narrower above and often destitute of the 

 dorsal appendage, or sometimes present only in a reduced form. The 

 species is very distinct by the long claw-like points to the sepals, and the 

 form of its lip. 



In Disperis the viscid surface of the glands of the pollinia appears to be 

 always directed towards the back of the flower. Fertilisation is therefore 

 probably effected by a retractive movement of tbe visiting insect. The 

 pollinia in this species, and I believe in most, become spirally revolute in 

 less than a second after withdrawal. The granules of the pollinia then 

 lie either nearly in a plane, or sometimes, as in I), imrpurata (see 

 plate 91), they project in every direction. In either case they are more 

 or less well fitted for striking the stigma from any direction. Yet I found 

 in 1884, that of 100 plants of this abundant species only 18 had been 

 visited by insects, and only 7 had the stigma pollinated {Orch. of Cape 

 Penins. p. 86). It should be added, however, that there appeared to be 

 some deficiency in the viscidity of the pollinary glands, and that therefore 

 insects may in some cases have visited the flowers without leaving any 

 trace. 



