FOLIAGE-LEAVES. Igi 



the leaf is glabrous ; if present, the degree of hairiness is 

 described by an appropriate adverb ; if the leaf is com- 

 pletely covered, it is villous or villose ; and if the hairs are 

 on the margin only, as in our Clintonia, it is ciliate. 

 Some leaves, like those of the Cabbage, have a kind of 

 bloom on the surface, which may be rubbed off with the 

 fingers ; this condition is described as glaucous. 



183. A few plants have anomalous leaves. Those 

 of the Onion are filiform. The Pitcher-Plant of our 

 northern swamps has very curious leaves (Pig. 169), 

 apparently formed by the turning in and ' cohesion of the 

 ' outer edges of an ordinary leaf so as to form a tube, 

 closed except at the top, and armed on the inner surface 

 with bristles pointing towards the base of the leaf. 



'184. . Finally, as leaves present an ahnost infinite 

 variety in their forms, it will often be necessary in 

 describing them to combine the terms explained above. 

 For instance, a leaf may not be exactly linear, nor exactly 

 lance-shaped, but may approximate to both forms. In 

 such a case the leaf is described as lance-linear, and so 

 with other forms. 



The following form of schedule may be used with 

 advantage in writing out descriptions of leaves. Two 

 leaves — one of Maple and one of Sweet Brier — are 

 described by way of illustration. If a leaf is compound, 

 the particulars as to outline, margin, apex, base, and surface 

 will have reference to the leaflets. 



The exercise-book prepared to accompany this work 

 contains a supply of blank schedules for leaf -description, 

 with space for drawings. 



