426 



ILLUSTKATIONS OF THE NATUEAL ORDERS. 



rable from each other, and often from a slender axis {carpophore), 

 into two achenia, or mericarps : tlie face by which these cohere re- 

 ceives the technical name of commissure : they are marked with a 

 definite number of ril/s (juga), which are 'sometimes produced into 

 wings : the intervening spaces (intervals), as well as the commissure, 

 sometimes contain canals or receptacles of volatile oil, called vittce: 

 these are the principal tenns peculiarly employed in describing the 

 plants of this difficult family. Embryo minute. Albumen hard or 

 corneous. — Ex. The Carrot, Parsnip, Celery, Caraway, Anise, 



Coriander, Poison Hemlock, &c. are common representatives of this 

 well-known family. Nearly all Umbelliferous plants are furnished 

 with a volatile oil or balsam, chiefly accumulated in the roots and in 

 the reservoirs of the fruit, upon which their aromatic and carmina- 

 tive properties depend : sometimes it is small in quantity, so as 

 merely to flavor the saccharine roots, which are used for food ; as in 

 the Carrot and Parsnip. But in many an alkaloid principle exists, 

 pervading the foliage, stems, and roots, especially the latter, which ren- 



FIG. 845. Conium maculatum (Poison Hemlock), a portion of the spotted stem, -with a leaf; 

 and an umbel with young fruit. 8-16. A flowering umbellet. 847. A flower, enlarged. 848, The 

 fruit. 849. Cross-section of the same, showing the involute (campylospfrmous) albumen of the 

 two seeds. 850. Longitudinal section of one mericarp, exhibiting the minute embryo near the 

 apex of the albumen. 



