124 



NATURAL EISTOBr OF PLANTS. 



Apivm graveolens. 



plants of the northern hemisphere of both worlds and of South 

 Africa, growing mostly in moist places and characterized by pinnate 

 leaves with dentate divisions, compound umbels with involucres and 

 involucels of an indefinite number of bracts, white flowers furnished 

 with very distinct pointed sepals, oval or oblong fruit, of which the 

 carpophore is indistinct or undivided, and primary ridges, obtuse, or 

 rather thick, slightly prominent, separate the furrows, in which are 

 multiple vittse, but variable in number. 



In the Celery (Apium), differing little from Carum, the petals are 

 most frequently entire or nearly so, white, pointed or obtuse, and 



the fruit (tig. 125), short, oval, or rather 

 wider than long, is laterally compressed, 

 contracted at the commissure, with 

 obtuse primary ridges and solitary 

 vittse. The carpophore is bifid or 

 undivided ; bipartite in Oreosciadium, 

 the fruit of which is a little more elon- 

 gate. The seed has nearly a circular 

 transverse section. They are perennial 

 or annual herbs, having pinnate or 

 ternatipinnate leaves, compound umbels, 

 with or without involucels; the involucre 

 nil or represented by a few bracts. 

 Apiastrum differs little' from Apium. 

 The didymous fruit is much more compressed, very contracted at 

 the commissure, rugose, with depressed stylopods and entire sessile 

 petals. They are annuals of North America, with compound umbels 

 resembling cymes, without involucres or involucels. 



Formerly Triania was referred to Apium and Pimpinella. It may, in 

 fact, be described as Apium, whose oval or didymous fruit, more or less 

 compressed perpendicularly to the partition, has its primary nervures 

 occupied by a large vitta representing a cylindrical column of resinous 

 substance. In the furrows, the vittee are nil or but httle developed. 

 The ridges are more or less prominent, smooth, or rugose, or cross 

 plaited, or bubble hke, and divided into small soft and superposed 

 lobes. This last form is particularly marked in Rumia, in which 

 the secondary ridges are sometimes visible though very little de- 

 veloped. The seeds are more or less channelled, and the vittse, 



Fig. 125. Fruit (?). 



