4 PACHYSTOMA. 



Reiclienbacli, and subsequently accepted by Bentham, who would, how- 

 ever, have preferred bringing it under Ipsea.* The true Pachy stomas^ 

 about seven or eight species, are leafless plants with inconspicuous 

 flowers of a totally different habit from the African plant here 

 described, and are scattered over parts of India and the Malay Archi- 

 pelago, but none of them possess any horticultural interest. 



Pachystoma Thomsonianum. 



Pseudo-bulbs orbicular, much like those of a Pleione, placed at short 

 intervals on a creeping rhizome, mono-diphyllous. Leaves lanceolate, 

 acuminate, 6 — 8 inches long. Peduncles slender, as long as the leaves, 

 one or two from the base of each pseudo-bulb, 2 — 4 flowered. Flowers 

 3 mches across ; sepals and petals white, lanceolate, acute, the dorsal 

 sepal the broadest, the lateral two narrower and falcate ; lip tliree- 

 lobed, the lateral lobes erect, sub-quadrate, greenish, densely spotted with 

 deep purple on the inner side ; middle lobe triangular, elongated, tapering 

 to a recurved point, and traversed by five raised longitudinal purple 

 lines which gradually coalesce towards the apex. Column arched, semi- 

 terete, green spotted Avith red. 



Pachystoma Thomsonianum, Echb. in Gard. Chron. XII. (1879), pp. 582 and 625, 

 icon. xyl. Id. Xe7i. Orch. III. p. 35, t. 213. Bot. Mag. t. 6471. Williams' Orch. 

 Alb. V. t. 220. 



A native of the mountains of Old Calabar, in West Africa, at a 

 moderate elevation, where it was discovered by Kalbreyer growing on 

 the trunks of trees, and at his request named after Mr. Thomson, 

 for a long time an earnest missionary in that unhealthy region. 

 The species is, as Sir J. D. Hooker justly remarks, " a very lovely 

 one ; its graceful form and the purity and brilliancy of its white, 

 and the vividness of its purple, render it one of the most beautiful 

 orchids of its type and habit, which remind one a good deal of 

 some Coelogynes " (Pleiones).t 



Cultural Note. — Inhabiting one of the hottest parts of the globe, 

 its geographical position indicates its chief cultural requirements, viz., 

 a constantly warm and moist atmosphere, such as is maintained in the 

 Phalsenopsis house. A suitable provision should be made for its sub- 

 terrestrial, creeping habit, such as a shalloAV pan or teak basket that 

 can be conveniently suspended near the roof-glass of the house. 



* Jour, of Linn. Soc. XVIII. p. 304. 

 t Bot. Mag. sub. t. 6471. 



