STERCULIACE^E 267 



short, and ending in the sinus, which is the real apex of the 

 cotyledons. A slender nerve is given off from each side of 

 the apex of the midrib and runs up close to the contiguous 

 edges of the sinus ; two short lateral ones are also given off 

 from the base ; and between the two pairs a strong nerve runs 

 to the apex of each lobe, giving off a few short branches on 

 each side. 



A curious case occurs in Hannafordia, containing a single 

 species only. The arilloid of the seed is cut up into numerous 



Cotyledons. The seedlings present four well-marked types 

 the first, that of Sterculia heterophylla (fig. 218), having 

 large, leathery, foliaceous cotyledons, which are broadly oblong, 

 obtuse at either end, petiolate, five-nerved with a well-marked, 

 reticulate venation, glabrous except the base and petioles, 

 which are shortly pubescent with glandular hairs. The 

 hypocotyl is also shortly pubescent and of moderate length. 

 A considerable number of the Sterculiaceae conform to this 

 type. Even Hermannia agrees in all the main characteris- 

 tics except in being much smaller, and in the discernible 

 venation being reduced to an indistinct midrib. 



The cotyledons of Heritiera, being large, thick, fleshy, and 

 occupying the whole of the exalbuminous seed, are, most pro- 

 bably, subterranean during and after germination. The con- 

 ferruminate cotyledons of Myrodia, and the fleshy ones of 

 Cola and Herrania, doubtless correspond with those of 

 Heritiera. A third and well-marked type occurs in the tribe 

 Dombeyeae, with deeply bifid cotyledons, well represented by 

 Pentapetes phoenicea (fig. 219). The seed-leaves of the latter 

 after germination are deeply bifid with ovate-oblong, obtuse, 

 diverging lobes, five-nerved at the base with two lateral ones 

 given off from the midrib near the sinus, thinly glandular- 

 pubescent at the margin, as well as on the rather slender 

 petioles. The cause to which the fission is due has been de- 

 scribed under ' Seeds.' A fourth type occurs in Lasiopetalum 

 dasyophyllum and L. ferrugineum (fig. 220). Here the coty- 

 ledons are linear, entire, acute, sessile, slightly narrowed to 

 both ends, minutely scaberulous with small elevations, slightly 

 connate at the base, or forming a shallow ridge around the 



