SAPINDACE^E 355 



the faculty of assimilation, acting chiefly as a store-house 

 of reserve-material, and to a tendency to become subter- 

 ranean. The first two leaves are opposite and tripartite 

 with the middle segment again trifid. Succeeding leaves 

 are alternate and more deeply divided; the fifth one being 

 biternate. 



The oblong or strap-shaped, sessile, five-nerved cotyledons 

 of Acer Pseudo-Platanus (fig. 252) present quite a distinct type 

 in the Order. Their shape and size are due to the manner of 

 folding in the seed and the shape of the latter. 



The first pair of leaves of A. Pseudo-Platanus are ovate, 

 acuminate, and cordate at the base, near which they are 

 doubly serrate-dentate. The cotyledons of A. campestre are 

 shorter than those of its congener and proportionately broader. 

 The same may be said of the first pair of leaves. 



The cotyledons of Dodonsea viscosa (fig. 253) in being 

 linear-lanceolate and one-nerved remind us very forcibly of 

 those of Billardiera amongst the Pittosporese. The first three 

 or four cuneate, trifid leaves also point in the same direction. 

 The fifth, sixth, and seventh leaves are elliptic and nearly 

 entire. 



The broadly obovate, emarginate, five-nerved and reticulate 

 cotyledons of Melianthus major constitute a well-marked type. 

 The foliaceous stipules, in being intrapetiolar and connate in 

 the upper portion, are also very striking. The first two 

 leaves are digitately trifoliolate, and succeeding ones impari- 

 pinnate with more or less winged petioles. 



The subterranean type of cotyledons is represented by 

 Sapindus insequalis (fig. 251). The petioles are of some con- 

 siderable length, although the cotyledons do not leave the 

 large globular seed. The first four leaves are greatly reduced 

 and scale-like, while eight succeeding ones are lanceolate, acu- 

 minate, and quite entire. In the adult state some species of 

 Sapindus have leaves consisting of one entire leaflet, while 

 others are abruptly pinnate. The cotyledons of Atalaya 

 diver sifolia are also strictly subterranean. The form of the 

 leaves is rather remarkable for this Order. The first three 

 are lanceolate and small, succeeded by two linear-lanceo- 



A A 2 



