EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



407 



bus juice, compound leaves usually marked with pellucid dots, and 

 small flowers ; with valvate petals, a two- to five-celled ovary, and 

 drupaceous fruit. Their balsamic juice, which flows when the trunk 

 is wounded, usually hardens into a resin. The Olihanum, used as a 

 fragrant incense, the Balm of Gilead, Balsam of Mecca, Myrrh, and 

 the Bdellium, are derived from Arabian species of the order ; the East 

 Indian Gum Elemi, from Canarium commune ; Balsam of Acouchi, 

 and similar substances, from various American trees of this family. 



793. Ord. Amyridacea) consists of a few West Indian plants, inter- 

 mediate as it were between Burseraceas and Leguminosse, and dis- 

 tinguished from the former chiefly by their simple and solitary ovary. 

 — Very probably this and the two last are to be recombined. 



794. Ord, Yitacea ( Vine Family). Shrubby plants, climbing by 

 tendrils, with simple or compound leaves, the upper alternate. 



FIG. 767. A branch of the Grape- Vine. 768. A flower ; the petals separating from the 

 base, and falling off together without expanding. 769. A flower from which the petals have 

 fallen ; the lobes of the disk seen alternate with the stamens. 770. Vertical section through 

 the ovary and the base of the flower : a, calyx, the limb of which is a mere rim : 6, petal, 

 having the stamen, c, directly before it ; and the lobes of the disk are shown between this and 

 the ovary. 771 A seed. 772. Section of the seed, showing the thick crustaceous testa, and 

 the albumen, at the base of which is the minute embryo. 772'. A horizontal plan of the flower. 



