426 



NATURAL HISTORY OF PLANTS. 



Acioa guianensis. 



The name Griff onia^ has been given to certain African plants 

 whose flower is constructed like that of A. guianensis, and which 

 cannot be generically separated from it. The fillet formed by the 

 fertile stamens may here be even longer than in the Guiana species, 

 and of these fertile stamens there are from 

 ten to fifteen and upwards, always unilateral. 

 The fruit is of very variable form.^ Already 

 we know of five or six species from the 

 west of tropical Africa.^ Thus constituted, 

 the genus Acioa consists of erect or climbing 

 trees or shrubs, with simple entire alternate 

 leaves, with two caducous lateral petiolary 

 stipules. The flowers are axillary or terminal, 

 collected into racemes simple, branched, or 

 composed of cymes. The bracts are pretty 

 often glandular, like those of Hirtella, and 

 the same may be the case with the sepals. 



Parastemon^ has flowers analogous to those of the Asiatic species 

 of Parinari which we described last. The receptacle is shallow and 

 cupuliform, and on one side of it is inserted a gynseceum, which may 

 or may not be fertile, for the flowers are polygamo-dicecious. On 

 its edges are borne a calyx of five imbricated sepals, a corolla of five 

 caducous petals, also imbricated, and an androceum which consists of 

 only two fertile stamens superposed to two sepals. Each of these 

 stamens is composed of a filament longer than the corolla, involute 

 in the bud, and a versatile introrse two-celled anther. The recep- 

 tacle is lined by a glandular disk, whose rim is especially thickened 

 at the side opposite the insertion of the stamens. The ovary possesses 

 a slender basilar style ; it becomes a glabrous oblong fruit, obtuse 

 at the apex, with a nearly woody pericarp containing a single seed, 

 whose thin membranous coats envelope an erect exalbuminous 

 embryo. The only known species of this genus is P. nrophylhis,^ 



• Hook. F., loc. cit., n. 10 (nee H. Bn.). 



2 " Nux sicca, ohlonga vel obpyriformis, suh- 

 compressa, Crustacea, 1-sperma, loctdo intuspilis 

 fulvidis hispido" (B. H., loc. cit.). As in Coue- 

 pia, &c., the carpel is superposed to sepal 3. 

 Moreover, we have shown that there is no cha- 

 racter sufficiently distinctive to mark oft' the 

 Coupi of Guiana generically from the species of 

 tropical Africa, of which we make a simple sec- 



tion in this genus under the name of Lorandra 

 (Hook. F., mss.). 



3 H. Bn., loc. cit., 223, 224, note. 



* A. DC, Ann. Sc. Nat., ser. 2, xviii. 208.— 

 Pi.., Ann. Sc. Nat., ser. 4, ii. 258.— B, H., Oen., 

 607, n. 7. 



* A. DC, loc. c//.— Walp., Ann., iv. 648.— 

 Einhelia urophylla Wall., Cat., 2309. — A. 

 DC, Tram. Linn. Soc, xvii. 131 



