THE TECTONA GROUP 



2159 



Orchid Subgroups. — Cyfripedium spectabile Salisbury, of the 

 Orchidace^e, is also said to possess venomous hairs, while C. 

 pubescens Willdenow is also known to cause a dermatitis. 



Jatropha mens Linnaeus, var. stimulosa Pohl, growing from 

 Virginia southwards, has stinging bristles and is called ' tread 

 softly.' 



Malache hirsuta Kuntze (Malvaceae), called by the natives of 

 Angola ' utiete,' which name it shares with other stinging species 

 of the Malvaceae in the same locality, has been investigated by 

 Wellman, who finds it to be armed with hairs containing a very 

 irritating substance. Other examples in the same locality are 

 species of the genera Sida and other species oi Malache, 



Cisus pruriens Welwitsch (Ampelidaceae) is another of Well- 

 man's stinging plants. The fruit is covered with stinging hairs. 

 It also has an irritating juice around the seeds, which burns the 

 throat if an attempt at mastication is made. 



Cnestis corniculatus Lam. (Connaraceae) is a vine common in 

 Angola and called sakupolopolo. Wellman had an unpleasant 

 experience with the hairs from a pod. 



Several other species belonging to the same genus and to Rourea 

 have stinging bristles on the fruit. 



Stizlohium stans Kuntze and S. pruriens De Candolle — synonym, 

 Mucuna pruriens (Leguminosae), and called by the natives of Angola 

 ' eyumbi ' — are armed with stinging pelose hairs; Mucuna pruriens 

 is the cowhage of the East and West Indies. 



IV. THE TECTONA GROUP. 



This group includes trees, the handsome wood of which is used 

 for the ornamentation of saloons, and also for making furniture. 

 The dried hard wood gives off dust, which is extremely irritating 

 to some people, while others appear not to be affected. One attack 

 appears to render the sufferer more liable to the complaint, and 

 although certain authorities claim that immunity may be acquired 

 by attacks, there appears to be considerable doubt on this point, 

 and, in fact, the evidence points to quite the reverse being true. 

 The best known of these dermatites was, until recently, that caused 

 by the wood of Tectona grandis Linnaeus, commonly called ' teak,' 

 which gives off a dry essential oil in the dust created by sawing, 

 and this produces a severe form of dermatitis in carpenters and 

 joiners, which tends to become generalized, and may be of long 

 duration, lasting sometimes for months. 



The effect of the dust of ' satin-wood ' — i.e., the wood of Chlorox- 

 ylon swietenia De Candolle from Ceylon and the East Indies, or 

 the wood of Fagara flava (synonym, Zanthoxylum flavum) from the 

 West Indies is to produce a dermatitis. These woods contain a 

 crystalline alkaloid (' chloroxylonne,' C22H230^N), which has been 

 carefuUy studied by Cash, who finds that twenty-two days after 

 application for the first time it causes a dermatitis which, beginning 



