470 ON SEEDLINGS 



EUPHORBIACEaE. 



Benth. et Hook. Gen. PL iii. 239. 



Fruit and Seed. The ovary is superior, usually three- 

 celled, often two- to four-celled, and sometimes one- or five- to 

 many-celled. The ovules are solitary in each cell or gemin- 

 ate and collateral, pendulous, anatropous, inserted on axile 

 placentas with a ventral raphe and superior micropyle, rarely 

 having a dorsal raphe with the micropyle close to the placenta. 

 The funicle is very frequently developed into a cellular, scale- 

 like, or hooded arillode, sometimes expanded and covering the 

 ovule wholly or in part. The fruit is capsular and falls away 

 at maturity into as many cocci as there are cells, leaving the 

 axis free. Sometimes it is baccate or drupaceous, divided into 

 cells, and indehiscent, very rarely breaking up into two or 

 three pyrenes ; or it may by abortion be one-celled and one- 

 seeded. The exocarp is thin or thickened and fleshy ; while 

 the endocarp is cartilaginous, crustaceous or hardened. The 

 seeds equal the number of cells or are fewer by abortion; 

 they have a crustaceous, rarely woody or membranous testa. 

 The endosperm is copious and fleshy or rarely cartilaginous or 

 papery. The embryo is central and straight, rarely incurved, 

 and almost equals the endosperm in length, and sometimes 

 in breadth. The cotyledons are broad and foliaceous, rarely 

 fleshy, or narrow and semiterete, very rarely thick and fleshy, 

 or very broad and twisted. The radicle is superior, and short 

 or rarely elongated ; and when the cotyledons are very broad 

 and auricled at the base, it is mostly enclosed or surrounded 

 by the auricles. 



The species of Euphorbia might also be divided into those 

 having pitted, smooth, or tubercular seeds. The seeds may be 

 divided into three groups. 



The seed of E. exigua is obtusely tetragonal and deeply 

 pitted on the two faces obliquely facing the placenta. The 

 cotyledons represent the narrowest type. They are oblong, 

 obtuse, plano-convex, rather narrower and much shorter than 

 the radicle. The seed of E. Lathyris is shortly oblong, slightly 



