42 BOTANY OF SOCOTRA. 



On comparing our plants with those of Aucher Eloy and with Jussieu's 

 description, we find one or two points wherein emendation may be made, and 

 as Schweinfurth obtained very fine fruit (we only have flowers) I am able to 

 complete the specific description which has been deficient in that character. 

 Jussieu describes the leaves as " oblonga lanceolato-obovata 2^—1^ poll, longa 

 li— | poll, lata." Whilst this typical form is found in leaves of Socotran plants, 

 yet they are at times quite oval or oblong-oval with a subcuneate base, and may 

 reach three inches in length. In the flowers I find all the sepals invariably " in 

 margine glandula minuta rubenti impressa." The petals too are about two- 

 and-a-half times the length of the sepals, and the filaments of the stamens are 

 almost equal in length to the sepals, so that the anthers project beyond them. 

 Of the fruit and seeds the following is a description : — Samarce tres oblongse 

 receptaculo trigono-conico aucto applicitse, lateribus rufescente-tomentosis, 

 supra extrorsumque in alam puberulam cum pilis runs productse 1 poll, longse 

 -£% poll, latae margine antico subincrassato vix curvato integro, postico tenuiore 

 subsinuato et curvilineari. Semina subdolabriformia, testa membranacea. 



Order XVIII. ZYGOPHYLLE^. 



A small order, chiefly found in desert and maritime districts of the tropical 

 and subtropical regions of the old and new world. The three genera found in 

 Socotra have a wide distribution, one of them, however, being limited almost 

 entirely to the old world. 



1. TRIBULUS. 



Tribulus, Linn. Gen. n. 532 ; Benth. et Hook. Gen. PI. i. 264. 



A small genus of very variable species, widely dispersed in the warm regions 

 of the world, and reaching Europe and North America. 



T. terrestris, Linn. Sp. 554; DC. Prod. i. 703; Boiss. Flor. Orient, i. 902; 

 Oliv. Flor. Trop. Afr. i. 283 ; Edgew. and Hook. fil. in Hook. Flor. Brit. Ind. i. 

 423 ; Franch. Sert. Soma], in Miss. Revoil 22 ; Sibth. Flor. Grsec. t. 372. 



T. mollis, Ehrenb. in Schweinf. Flor. yEthiop. 29. 



Socotra. Common on the plains. B.C.S. nn. 92, 222. Schweinf. n. 383 

 in lit. 



Distrib. A wide-spread tropical weed. 



We have on Socotra two distinct forms of this plant. One, the type, with 

 the shortly pedicellate flowers and the slightly hairy fruits. The other (n. 222) 

 which in a less variable plant might be almost a distinct species, has very 

 long pedicels, and the fruit is densely hispid. It resembles most nearly Schwein- 

 furth's centra] African plant, named Tr. mollis by Ehrenberg. 



