III.] 



UMDELLIFERAL. 



The face of union of the two carpels is called the commis- 

 sure. In the substance of the thin pericarp are often found 

 minute, longitudinal canals, containing essential oil. These 

 are the vittce. They may be found, when present, by making 

 a careful transverse section of the ripe fruit. 



Frc. 138. One of the fruit-carpels 

 of [{eracieu7n, showing four 

 vittae on the dorsal face. 



Fig. 1 39. Transverse section of samt, 

 showing the position of the vittae ; also 

 the embryo surrounded by copious 

 albumen. 



In Hydrocotyle the umbels are simple. H. asiaiica is 

 common in swamps in India and tropical Africa, occurring 

 also in South America and Australia. This wide distribu- 

 tion is shared by numerous plants which affect similar 

 situations, growing either wholly or partially in water, 

 probably on account of the facilities afforded to their 

 dispersion by w^ater-fowl. 



The carpels of Umbelliferae are usually marked by lines, 

 ridges, or wings answering to the dorsal and sutural lines of 

 the cohering (and adhering) sepals. In Carrot the ridges 

 are bristly, in Praiigos w^inged. The latter is common in 

 Thibet, where it serves as a valuable food for sheep. 



The Family includes many dangerous plants, as well as 

 some valuable esculents. Some species afford aromatic 

 fruits or medicinal resins. Hemlock (Comum), the State 



