230 ON SEEDLINGS 



placentas also vary greatly in length in the different species, 

 some rising but a short way above the base of the ovary, 

 while in other cases they nearly equal the length of the 

 cavity. The ovules vary from two to many on each placenta 

 and are erect and anatropous, with the raphe on the ventral 

 aspect and an inferior micropyle. The fruit is a capsule de- 

 hiscing by valves and liberating the seeds, which are furnished 

 with a curious contrivance for their distribution. In some 

 cases they are prolonged into a slender beak covered with 

 long silky hairs, while others have no beak but are covered 

 all over with long hairs, and a third type is furnished with 

 wings. The seeds contain a mealy or fleshy endosperm, 

 sometimes in very small quantity, or there may be none at 

 all as in Tamarix and Myricaria. The embryo is straight 

 with flat cotyledons, and a short radicle close to the hilum ; 

 and where endosperm is wanting it entirely fills the seed, to 

 which it conforms in shape. 



The Tamariscineae include some forty species distributed 

 amongst five genera, and consist of very finely branched 

 shrubs, rarely trees or rigid herbs. The leaves are alternate, 

 minute, and often scale-like. 



ELATINE.E. 



Benth. et Hook. Gen. PL i. 162. 



Fruit and Seed. The ovary contains from two to five cells, 

 corresponding to the number of the sepals and petals in the dif- 

 ferent species. The ovules are numerous on the inner angle of 

 the cells, horizontal or ascending, anatropous, with a lateral or 

 nearly superior raphe. The fruit in dehiscing splits along the 

 inner edge of the septa, leaving a central column bearing 

 the seeds, or often along the outer edge, leaving the septa 

 attached to the central column. The seeds are numerous, 

 cylindrical, straight, or slightly curved as in Elatine triandra, 

 or very much curved like the head of a shepherd's staff as in 

 E. Hydropiper, strongly and closely striated transversely, 

 and exalbuminous or with a thin layer only of endosperm. In 



