PHANEROGAMS — PROFESSOR BAYLEY BALFOUR. 139 



12. BLAINVILLEA. 



Blainvillea, Cass, in Diet. Sc. Nat. xxix. (1823), 493 ; Benth. et Hook. Gen. PL ii. 369. 



A small genus of about six species of erect herbs widely spread in the 

 tropics of both hemispheres. 



B. rhomboidea, Cass, in Diet. Sc. Nat. xxix. (1823), 494 ; DC. Prod. v. 

 492; Oliv. and Hiern in Oliv. Flor. Trop. Afr. iii. 375. 



B. Gayana, Cass, in Diet. Sc. Nat. xlvii. (1827), 90 ; Oliv. and Hiern loc. cit. 



B. latifolia, DC. in Wight Contrib. (1834), 17 ; Hook. fil. Flor. Brit. Iud. iii. 305. 



Soeotra. Not uncommon. B.C.S. n. 596. Schweinf. n. 763. 



Distrib. Round the world in the tropics. 



Cassini's two species, it would appear, are, as Bentham and Hooker {loc. cit.) 

 point out, forms of one widely-spread species, to which also De Candolle's plant 

 is justly referred by Hooker. The size and margination of the leaves, length 

 of peduncle, size and feature of the capitula, relied upon by Cassini and De 

 Candolle, are very variable, and not of specific value. Oliver and Hiern (loc. 

 cit.) remark that tropical African specimens referred by them to B. rhomboidea, 

 Cass., " differ from a type specimen that we have seen and from Brazilian ones 

 in the tubercles of the achenes ; the Zanzibar specimen is sparingly tubercled ; 

 an Arabian one is also tubercled." In this character there is great variation. 

 From Soeotra alone we have specimens showing extremely smooth or only 

 slightly foveolate achenes, whilst in others the surface is glossy and strongly 

 tuberculate and strigose, and there are many intermediate forms. 



13. BIDENS. 



Bidens, Linn. Gen. n. 932 ; Benth. et Hook. Gen. PL ii. 387. 



A large genus of chiefly American herbs. Some are cosmopolitan. 



B. pilosa, Linn. Sp. 1166; DC. Prod. v. 597; Oliv. and Hiern in Oliv. 

 Flor. Trop. Afr. iii. 392 ; Hook. fil. Flor. Brit. Ind. iii. 309. 



Nom. Vern. Mdanhi or Heddanin (Schweinf.). 



Soeotra. Common. B.C.S. n. 715. Schweinf. nn. 296, 575. 



Distrib. A common weed in warm countries. Schweinfurth sends a 

 form of this, with deeply trifid leaves and incised segments, from Tamarida 

 (n. 296), for which he gives as the vernacular name "Heddanin." 



14. SENECIO. 



Scnecio, Linn. Gen. n. 953 ; Benth. et Hook. Gen. PL ii. 446. 



A very vast cosmopolitan genus. The section Kleinia, to which our 

 Socotran species belongs, embracing some twenty species, with few exceptions 



