OEGANS OF GROWTH. 



29 



Sometimes they are hollow and closed at the top, as an 

 onion leaf, or in the form of an urn or vase, as in pitcher 

 plants. 



Leaves are either simple or compound. Simple leaves 

 are linear when long and narrow and of nearly uniform 

 width, such as grasses ; lanceolate, when broad at the 

 base, and tapering to a point like a lance, as Adam's 

 needle ; elliptical, oval, or ohlong, when longer than 

 broad, with obtuse ends ; ovate, broader at one end like 

 an egg ; rotund, round, in the form of a circular disc, as 

 in pennywort, sacred bean, and the Victoria lily. These 

 words are sometimes used conjointly, thus ovate-lanceo- 

 late, ovate-elliptical, and ohlong-lanceolate, which de- 

 notes that the leaf partakes in some degree of both 

 forms. Leaves tapering to a point are called acuminate ; 

 cordate (heart-shaped), when lobed at the base in the 

 form of a heart, as in water lilies ; hastate, when the 

 lobes project like a halbert. 



The margins are either entire, or with little blunt 

 projections like teeth, toothed or dentate; or sharp like 

 a saw, serrate ; sometimes they are deeply gashed, 

 laciniated, as in the artichoke ; pinnatifid, when, the 

 divisions (lacince) are uniform and divided to near the 

 midrib, as in the common polypod fern. When the 

 margin is but slightly rounded or wavy, it is termed 

 sinuose; when waved up and down, undulate or crisped. 

 These terms apply chiefly to ohlong and lanceolate 

 leaves. Those of a roundish form, or as wide as long, are 

 called deltoid, vfhen their margins are also entire; sinuose, 

 when more or less deeply laciniated, the divisions being 

 called lobes; when five-lobed they are called palmate 

 or hand-like, as in the oriental plane ; or flahellate, fan- 

 like, having the surface plaited, as in fan palms. 



