1 66 PHARMACEUTICAL BOTANY 



apex of the petiole. When these are two in number the leaf is 

 bifoliate, or binate; if three in number, trifoliate, or ternate, as in 

 Menyanthes; when four in number, quadrifoliate, etc. If each of 

 the leaflets of a palmately compound leaf divides into three, the leaf 

 is called biternate; if this form again divides, a triternate leaf results. 

 Beyond this point the leaf is known as decompound. In the case 

 of pinnately-compound leaves, when division progresses so as to 

 separate what would be a leaflet into two or more, the leaf becomes 

 bipinnate, as the compound leaves of Acacia Senegal or on the new 

 wood of Gleditschia; if these become again divided, as in many 

 Acacia species, the leaf is termed tripinnate. Examples of decom- 

 pound leaves seen in Cimicifuga and Parsley. 



Leaf Texture. Leaves are described as : 



Membranous, when thin and pliable, as Coca. 



Succulent, when thick and fleshy, as Aloes, and Live Forever. 



Coriaceous, when thick and leathery, as Eucalyptus, Uva Ursi 

 and Magnolia. 



Leaf Color. Petaloid, when of some brilliant color different from 

 the usual green, as the Coleus and Begonia, and other plants which 

 are prized for the beauty of their foliage rather than their blossoms. 



Leaf Surface. Any plant surface is : 



Glabrous, when perfectly smooth and free from hairs or protuber- 

 ances. Example: Tulip. 



Glaucous, when covered with bloom, as the Cabbage leaf. 



Pellucid-punctate, when dotted with oil glands, as the leaves of 

 the Orange family. 



Scabrous leaves have a rough surface with minute, hard points. 



Pubescent, covered with short, soft hairs. Example: Strawberry. 



Villose, covered with long and shaggy hairs. Example: Forget- 

 me-not. 



Sericious, silky. Example: Silverleaf. 



Hispid, when covered with short, stiff hairs. Example: Borage. 



Tomentose, densely pubescent and felt-like, as the Mullein leaf. 



Spinose, beset with spines, as in the Thistle. 



Rugose, when wrinkled. Example: Sage. 



Verrucose, covered with protuberances or warts, as the calyx of 

 Chenopodium. 



