RUBIACE^E 



73 



PIG. 438. 



scurely reticulate, thinly pubescent above, with short hairs directed 



towards the apex, less so beneath, and glabrescent when old 



stipules similar to the leaves but smaller, at least 



in the early stage ; petioles short, semiterete, 



slightly tapered upwards, channelled on the upper 



side, slightly scaberulous with short hairs, and an 



interpetiolar transverse line of hairs or small 



bristles. 



First pair of leaves ovate, obtuse, cordate at 

 the base, three- or less distinctly five-nerved ; 

 stipules similar but much narrower and less dis- 

 tinctly nerved, petiolate, cordate at the base. 



Gralium Aparine, L. (figs. 489, 440). 



Fruit didymous, densely covered with hooked 

 prickles, indehiscent, falling away in two separate 

 pieces. 



Seed subglobose, ventrally attached and peltate, 

 with a deep round hollow on the ventral aspect 

 caused by the indentation of the testa, dark brown 

 or black, finely reticulate ; raphe ventral in the 

 interior of the cavity ; radicle inferior, close to the edge of the 

 cavity. 



Endosperm copious, pale subtransparent white, horny. 



Embryo curved and reaching from the micropyle near the outer 

 edge of the ventral cavity for about three-quarters the distance to 

 the other side, colourless, embedded in the endosperm ; cotyledons 

 oblong-ovate, obtuse, emarginate, covered on the upper surface with 

 clear colourless or crystalline points or prickles directed towards the 

 apex, trinerved at the base with stronger lateral nerves upwards, 

 all of which are incurved, the basal ones uniting with those above 

 them, which then converge and unite in the apical sinus. 



During germination the endosperm is absorbed, and the coty- 

 ledons increasing at the same time fill the internal cavity of the 

 seed ; the radicle pushes its way into the soil where it throws out 

 lateral rootlets ; the hypocotyl is the first to appear above ground 

 and pulls the now largely developed cotyledons out of the soil, 

 without the testa if the seed is buried sufficiently deep, other- 

 wise the testa is carried up on their tips. The cotyledons were 

 folded over the large indented process of the pericarp, and are thus 

 necessarily concave, the emarginate apex abuts on the upper side 

 of the same indentation, and they are undulated or crisped in the 

 middle owing to the resistance at their apex and base. The testa 



