92 XXIV. STERCULiACE^. [Walthei'ia 



GOLUNGO Alto. — A shrubby herb, branched from the base, 2 to 3 ft. 

 high, erect ; flowers yellow, at length fuscous when withering ; in rather 

 dry open stations, near Canaulo, by the Ambaca road ; fl. and immature 

 fr. beginning of June 1856. No. 4721. About Sange, fl. No. 4720. 



HuiLLA,- — An undershrub, 2 to 3 ft. high, with numerous stems and 

 yellow flowers ; in rather moist thickets, near Humpata, sporadic : fl. 

 April 1859. No. 4725. 



Theohroma Cacao L. — Prince's Island. — A small cultivated tree, 

 8 to 10 ft. high, with spreading branches ; frequently cultivated in 

 shady woods at elevations ranging from 300 up to 2000 ft. above sea- 

 level ; with ripe fr. Sept. 1853. No. 4713. Coll. Carp. 287. 



10. BYTTNERIA L. in P. Loefling Iter Hispan. p. 313 (1758); 

 Benth. & Hook. f. Gen. PI. i. p. 225 {Buettneria). 



1. B. africana Masters in Oliv. Fl. Trop. Afr. i. p. 239 

 {Buettneria); var. ? angolensis. 



Golungo Alto. — An undershrub, woody at the base, climbing to 

 a considerable height, and herbaceous above after the manner of a 

 D'loscorea ; leaves of a deep-green hue, glossy on both sides ; flowers 

 hermaphrodite ; petals 5, white ; stamens 5, opposite to the petals, 

 situate in recesses of the urceolate disk, included, anthers 5 ; stigma 

 hyaline, peltate, 6-lobed or 6-rayed ; fruit as large as a good-sized walnut, 

 nearly 1 in. in diameter, densely and rigidly echinate outside, very 

 hard, spherical. In the primitive forests of Sobato de Quilombo- 

 Quiacatubia, alongside the river Muio, fl. Feb. 1855 ; Queta, fr. end 

 of Dec. 1856. No. 351. 



XXV. TILIACEiE. 



The Tiliacese, which embrace some of the most widely distributed 

 plants in the Flora of Angola, occur for the most part only as 

 bushes or herbaceous plants; during his travels in Angola and 

 Benguella, Welwitsch never met with those genera, which nearer 

 the Equator are represented by regular tree-forms ; he thought, 

 however, that on closer investigation such might be found in the 

 more northern Congo district. It is a remarkable phenomenon 

 that Tiliacese throughout the North Temperate Zone consist of 

 trees ; while the species which occur in tropical regions, especially 

 in Africa, consist mostly of shrubs and frequently of herbaceous 

 plants, the contrary relation of which holds in the case of most 

 other Natural Orders. 



The Tiliaceas increase gradually from the coast to the interior 

 of the country, not only in the number of species, but also in that 

 of the individuals. The species of the genera Corchorus and 

 Triimifetta are for the most part herbaceous, while those of the 

 genera Grev)ia and Glyphaea comprise only shrubby forms or 

 woody climbers. The genera Corchorus and Grewia preponderate 

 in the littoral districts, while the species of Triimifetta are espe- 

 cially fiequent in the region of primitive forests and high table- 

 lands, and Glyjyhcea belongs exclusively to the interior highlands, 

 chiefly in secondary woods. Grewia and Triumfetta form, in 

 company with Malvaceje, the principal part of the underwood in 



