396 ON SEEDLINGS 



entire, and variable in shape and size. The cotyledons of 

 Edwardsia chilensis (fig. 294) are fleshy and green ; and the 

 leaves show a gradual evolution from the first, which is small, 

 obovate, and simple. A rather exceptional case occurs in Cas- 

 tanospermum australe (fig. 295), which has depresso-globose, 

 fleshy cotyledons of enormous size. It is comparable to a 

 species of Cola, 1 one of the Sterculiaceae, but in the latter 

 there are four cotyledons. 



Myroxylon peruiferum has also subterranean cotyledons. 

 The two first leaves are five-foliolate and opposite, succeeding 

 ones have more numerous leaflets, the uppermost of which are 

 the largest and the basal ones the smallest. The leaflets are 

 all lanceolate. 



SUBORDER C^SALPINIE^:. 



Tribe Eucasalpiniea. In the suborder Papilionacefe 

 cotyledons with a cordate base are comparatively rare, while 

 in the Csesalpinieae they are very frequent. This is due to a 

 difference in the seed and embryo, the former generally con- 

 taining endosperm, while the latter is straight, and the radicle 

 is included between the auricles of the cotyledons, or projects 

 slightly beyond them. The embryo is nearly as long as the 

 endosperm, but differs considerably in outline in different 

 species according to the shape of the seed. 



The cotyledons of Csesalpinia tinctoria (fig. 297) are orbi- 

 cular with a cordate base, strongly trinerved, with the nerves 

 branched. The leaves are stipulate and stipellate ; the first 

 two are abruptly pinnate with four pairs and three pairs of 

 leaflets respectively. The third leaf is abruptly bipinnate, 

 with one pair of pinnae, each of which bears three pairs of 

 leaflets. The cotyledons of Poinciana Gilliesii (fig. 298) differ 

 in being oblong and five-nerved. The first leaf is abruptly 

 pinnate. 



One of the most remarkable exceptions occurring in the 

 whole Order is met with in Haematoxylon campechianum 

 (fig. 296). The cotyledons are bipartite, with divaricate un- 

 symmetrical lobes of membranous texture. 



Tribe Cassiea. The various species of the genus Cassia 

 1 Vide supra, p. 270. 



