PARIETALES. 551 



A bitter principle, which is sometimes emetic and purgative, per- 

 vades the order. 



Some South African species of PolygaZa are grown as ornamental 

 plants in conservatories. A few have a little reputation as medicines. 



Order Tremandreee, containing a few Australian shrublets. 



Order Pittosporaceee. Trees and shrubs with alternate leaves, 

 and actinomorphic flowers ; petals cohering into a tube. Species 

 ninety, of Africa, India, China, and Australia. 



Pittosporum Tobira is a common plant in conservatories. 



P. undulatum.oi Australia, attains a height of twenty to twenty-five 

 metres (70 to 80 ft.), and its wood resembles Boxwood. 



Climbing species of Sollya and other genera are grown in green- 

 houses. 



6O3. Cohort XXXV. Parietales. Flowers actinomorph- 

 ic or zygomorphic ; stamens definite or indefinite ; ovary 

 usually one-celled, with parietal placentae. 



Order Bixineee. Trees and shrubs with alternate simple leaves, 

 actinomorphic flowers, and generally indefinite stamens ; seeds with 

 endosperm. Species 160, mostly tropical. 



One or two species of Amoreuxia barely reach our extreme South- 

 western border. 



Bixia Orellana, a small South American tree now cultivated in many 

 tropical countries, produces fruits whose orange-red pulp when pre- 

 pared and dried is the valuable dye known as Arnotto. 



The fruits of some species are eaten, and a few gums are derived 

 from others. 



Order Canellacese, containing four or five species of tropical trees. 



Canella alba yields Canella Bark, which is used in medicine. 



Order Violaceee. The Violet Family. Herbs and shrubs with 

 mostly .alternate leaves, zygomorphic flowers, and definite stamens; 

 seeds with endosperm. Species 240, widely distributed in temperate 

 and tropical regions. 



An emetic and laxative principle is common in the plants of this 

 order. 



The genus Viola, the Violets, includes about half of the species of 

 the order ; many of these are indigenous to parts of the United States, 

 and nearly all of these, as well as the exotic species, are ornamental. 



V. odorata, the Sweet Violet, and V. tricolor, the Pansy, both natives 

 of Europe, are common in gardens and door-yards. Of the latter there 

 are almost numberless varieties. 



Several Brazilian shrubby plants of the order are cultivated in green- 

 houses. 



The root of lonidium IpecacuanM, a Brazilian shrub, is the White 

 Ipecacuanha of pharmacy. 



