308 



NATURAL mSTOEY OF PLANTS. 



apple. Tliis fleshy outside is an indusium formed by the now suc- 

 culent receptacle ; and the partitions between the carpels are simi- 

 larlv altered. The fruits themselves enclosed in the cavities of this 

 sac are drupes, but the pericarp varies greatly in consistency and 

 thickness. In S. guianensis, Apiosycc, &c., it consists of a hard stone, 

 bristling outside with very prominent woody points. The mem- 

 branous epicarp is almost in contact with this over the lower two- 

 thirds, where the mesocarp is also reduced to a thin membranous 

 layer. But above, the latter swells and becomes thick and fleshy, 

 so that here the pericarp is that of any ordinary drupe. The kernel 

 is a single ascending seed, with membranous coats, and copious 

 fleshy albumen, containing near its apex a little embryo whose coty- 

 ledons are superior (fig. 355). 



In the female flower, as in the fruit, the surface of the sac is 

 usually smooth, bearing no other appendages than the pieces of the 

 perianth. But in several species which have been 

 made into a section apart, the surface is covered 

 with a pretty large number of more or less marked 

 projections, of divers forms, which should be con- 

 sidered as prickles (Fr., aigidlloiis — fig. 350). 



The genus Siparuna consists of small trees or 

 shrubs from tropical America, especially abundant 

 in Brazil, Peru, and Gruiana. Some are found in 

 the Antilles and Mexico. Upwards of sixty species 

 are already known.' Their leaves are opposite, 

 rarely verticillate, aromatic, sprinkled with pellucid 

 more or less projecting glands, sometimes glabrous, sometimes 

 covered, like most of the organs, with a down that may be very 

 thick. The flowers are arranged in axillary cymes, sometimes very 

 regularly biparous, sometimes branching symmetrically only at first, 

 and afterwards becoming uniparous and unsymmetrical by the abor- 

 tion of one flower in each generation. 



Sipanina muricata. 



t*s-\ 



-3^- 



Fig. 356. 

 Female flower ^^±). 



AuBL., <p. cit., 8G5, t. 333.— II. & Pav , 

 Syst., 264; Pro/lr., t. 29.— H. B. K., Nov. Oen. 

 et Spec. PI. JEquin., \\. 170.— Pcepp. & Endl., 

 Nov. Oen. et Spec, ii. 47, t. 161.— Sl'KENG., 

 Syst. r,'ff., ii. 545.— Rkxth., PI. Hartweg., 250. 

 — C'kueo., Linnaa, sx. 113. — Beukl., Prim. Fl. 



Port., 146.— TuL., Ann. Sc. Nat. ser. 4, iii. 32; 

 Man., 314 ; in Mart., Fl. Bras., Monimiac, 294. 

 — G;:iSEB.,i^Z. Brif. W. Ind., 9. — Seem., Journ. 

 of Bat., ii. (1864), 342.— A. DC, Seem. Journ. 

 of Bot., iii. (1865), 219 ; Prodr., he. cit., 643.— 

 Walp., Ann., iv. 89. 



