DICOTYLEDONES : GAMOPETALiE. 641 



with parietal or axile placentation : ovules numerous : seed with 

 endosperm. Shrubs with simple exstipulate leaves, and schizo- 

 genous resin-ducts. 



Pittospomm Tobira, undulatum, crassifolium, are ornamental shrubs from 

 Australia. 



Order 5. Hamamelidace^. Flowers frequently diclinous and 

 apetalous, 4-5-merous, perigjnous, or nearly epigynous : stamens 

 typically in two whorls, but one or other of the whorls is fre- 

 quently suppressed ; ovary usually bilocular : leaves stipulate. 



Hamamelis lirginica, the Witch-Hazel, is an ornamental shrub from North 

 America, the leaves of which somewhat resemble those of the Hazel. Other 

 well-known shrubs are Parrotia, Liquidambar, etc. 



Order 6. Podostemacej;. Small aquatic plants: flowers some- 

 times diclinous or dioecious: perianth generally much reduced, and 

 sometimes completely suppressed : stamens one or many, some- 

 times monadelphous : ovary superior, 1- 2- or 3-locular : seeds 

 many. 



A very remarkable group of plants, growing on stones, etc., in swiftly flowing 

 streams and rivers of the tropics : so complete is their adaptation to their en- 

 vironment that they have more or less completely assumed the general habit 

 and appearance of Lichens, Algae, Mosses, and Liverworts. 



SUB-CLASS II. GAMOPETAL^. 



Flowers nsually ambisporangiate : perianth differentiated into 

 calyx and corolla; calyx usually gamosepalous ; corolla generally 

 gamopetalons, in some cases suppressed: ovary nsually syncarpous. 



SEKIES L HYPOGYN^. 



Ovary superior (except in Vacciniaceee) : stamens epipetalous, 

 or free and hypogynous. 



Cohort I. Lamiales. Flower pentamerous, usually dorsiven- 

 tral: the formula is generally >^ K (5) (G (5) A 6) &^; corolla 

 usually bilabiate, the two posterior petals being connate and 

 forming a frequently helmet-shaped (galeate) projecting upper 

 lip; the anterior petal, with the two lateral petals, forming the 

 under lip: stamens epipetalous; the posterior stamen is usually 

 suppressed or is a staminode ; the two lateral stamens are generally 

 shorter than the two anterior ones, so that the flower is didynam- 



