DISA. 169 
younger, in ‘Orchidiographiw Europe,’ t. 2, f. 18, 19, 20 (analysis) ; 
Bolus, in Journ. Linn. Soc., vol. xix. p. 234 (analysis). 
Has. Mountain-sides and tops, Table Mountain, &c., 1200—3500 ft.; fl. Feb.— 
March, common; Bolus, 4884; Herb. Norm. Austr.-Afr., 167. — Extends to Gena- 
dendal Mt., and probably further eastward. 
The sepals are an intensely bright and beautiful blue; the petals 
usually purple below, with a green upper limb; the lip pale blue, or 
white, edged with dark blue or purple. Lindley described the flower 
as having two pollinary glands. Reichenbach (‘De Pollinis Orchide- 
arum Genesi,’ p. 81) found specimens with both one and two glands. 
I have never been able to find more than one gland, although I have 
examined scores of flowers. On this variation Reichenbach (loc. cit.) 
observes :—‘‘ There are either two (or three?) genera with exactly the 
same external appearance and different gynostemia, or one genus with 
a 2- (or 3-?) morphous gynosteme.”” Lindley also describes a dorsal 
linear appendage, tuberculate on either side, and situate in front of the 
anther. An inspection of Lindley’s drawing shews that this organ is 
that which I have called the middle lobe of the rostellum; while his 
middle lobe is apparently a fold of the rostellum drawn out in the dis- 
section of the dried specimen, but which is quite invisible in the 
living state. It is one of the commonest species within our limits, 
has a rather long flowering period, and attracts universal observation 
by its beauty and brilliancy; so much so, that Lindley, in dedicating 
it to the great astronomer, Herschel (who also was a great orchid-lover 
and cultivator), felicitously speaks of it as ‘‘species hee pulcherrima 
colore coeli australis intensé ceruleo superbiens.”’ It is very generally 
accompanied by D. ferruginea, Swartz. Its nearest ally seems to be 
D. purpurascens. In spite of repeated efforts, it does not appear to 
have been successfully grown in England; the drawing from which 
Ker’s figure was taken was made at the Cape in Masson’s time. 
41. Disa purpurascens, Bolus, in Jown. Linn. Soc., vol. xx. 
(1884), p. 482.— Glabrous, erect, 16-18 in. high ; leaves 6-8, radical, 
linear, grass-like, lax, shorter than the scape ; scape flexuous, clothed 
with several acute membranous sheaths; raceme laxly 2-3-flowered ; 
bracts broadly ovate, acute, membranous ; side sepals ovate-oblong, 
acute, spreading, 9 lines long; odd sepal galeate, with a subrotund 
mouth, 7-8 lines across, subacute, with an ascending spur about 2 lines 
long ; petals linear in the middle, dilated into a rounded toothed limb 
above, bent forward, expanded and crenulate below, adnate to the 
column, about 5 lines high; lip ovate, crenulate, with inflexed margins; 
anther deflexed; the single gland of the pollinia wider than long ; 
rostellum 8-lobed, wider than long. 
