I'terodiscHs] xciii. rEUALiACE.K. 795 



than in other tropical countries; but as they consist mostly of 

 herbs tliey tlo not greatly affect the physiognomy of the vegetation. 



The tribe Pedaliese has only one representative in the collection, 

 and of that one only a single specimen was fovnid ; but it is very 

 probable that rucaria procuuihpns Burch., the grapple plant, 

 occurs in the southern part of ]\Iossamedes on the sandy Cunene 

 plains. 



The tribe Sesamea? is most frecjuent about Benguella and in 

 the Massamedes district. Two species of Sesavium, namely, 

 S. angolense and S. rigidnm, have both opposite and alternate 

 leaves on one and the same specimen. The cultivation of S. 

 orientals, which is carried on with profitable results in India, 

 Egypt, Mozambique, etc., was started in Angola during the 

 time when Pedro Alexandi-ipho do Oonha was governor-general, 

 and again at a later period before Welvvitsch's time, though 

 always with but small success ; but the experiments appear nut 

 to have been made in the parts of the province best adapted for 

 the purpose. The colonists complained that the exceedingly 

 irregular ripening of the seeds so reduced the crop that the 

 cultivation of this oil-plant had resulted in a loss; during the 

 latter part of his travels, however, Wehvitsch saw in the interioi-. 

 chiefly on the high plateau east of Pungo Andongo, the plant 

 cultivated by tlie negi-oes, though only in small quantities and foi- 

 their own use, and he was firmly convinced that trials made by 

 experienced colonists and in properly chosen districts in the 

 highlands would lead to favourable results. The negroes of 

 Pungo Andongo cultivate it, not for the extraction of oil, but for 

 making cakes, which they bake with the crushed seeds, and which 

 they look upon as a delicacy. In Cazengo the cultivation had 

 been attempted and given up, as it was found that birds devoured 

 the seeds of the Sesamum before they ripened, and that Arachi.s 

 ki/po(jcHa afforded a far more certain and profitable yield for the 

 production of oil. 



Several species possess roots containing a I'ed dyeing material,, 

 which even in the herbarium stains paper, and they might 

 perhaps be used for dyeing pui-jjoses ; this material is most 

 strongly developed in Sesamvm tripJujUwa, a species which is 

 widely distributed from the banks of the Maiombo behind 

 Mossamedes up to the high plateau of Huilla. A mucilaginous 

 infusion is obtained from species found about Lopollo and JIuilla. 

 ;S'. pentaphijlhuii with its large violet-purple flowers, and still more 

 so the S. anyolense of Pungo Andongo, are very ornamental plants, 

 and probably might, at least in the warmer European countries, be 

 grown in tlie o{)en air. 



1. PTERODISCUS Ifook.; Benth. d- Hook. f. Gen. PI. ii. p. 1U57. 



1. P. aurantiacus Welw. in Ti-ans. Linn. Soc. xxvii. p. 5.3 

 (18G9); Schinz in Verb. Bot. Brandenb. x.xx. p. 181 (23 June 1888). 



MossAMEDKs. — A decumbent herb, glaucous-pruinose beneath : root 

 thick, fusiform, almost napiform : stem prostrate, succulent, nearly 



