THEIB FORMS. 



161 



termed lyrate, or lyre-shaped (Fig. 278) ; and a lyrate leaf with 

 sharp lobes pointing towards the base, as in the Dandelion (Fig, 

 279), is called runcinate. A palmately veined leaf is in like man- 

 ner said to he palmately hied (Fig. 2^^), palmately cleft (Fig. 265), 

 palmately parted (Fig. 266), or palmately divided (Fig. 267), ac- 

 cording to the degree of division. The term palmate was originally 

 employed to designate a leaf more or less deeply cut into about five 

 spreading lobes, bearing some resemblance to a hand with the fingers 

 spreading ; and it is still used to designate a palmately lobed leaf, 

 without reference to the depth of the sinuses. A palmate leaf with 

 the lateral lobes cleft into two or more segments is said to be pedafe 

 (Fig. 249), from a fancied resemblance to a bird's foot By desig- 

 nating the number of the lobes in connection with the terms which 

 indicate their extent and their disposition, botanists are enabled to 

 describe all these modifications with great brevity and precision. 

 Thus, apalmately three-parted leaf is one of the radiated-veined kind, 

 which is divided almost to the base into three segments (Fig. 266) ; 

 a pinnately five-parted leaf is one of the feather-veined kind cut into 

 five lobes (two on each side, and one terminal), with the sinuses ex- 

 tending almost to the midrib : and the same plan is followed ia de- 

 scribing cleft, lobed, or divided leaves. 



284. The segments of a lobed or divided leaf may be again di- 

 vided, lobed, or cleft, in the same way as the original blade, and the 

 same terms are employed in describing them. Sometimes both the 

 primary, secondary, and even tertiary divisions are defined by a 

 single word or phrase ; as hipinnatifid (Fig. 280), tripinnatifid, 

 Mpinnately parted, tripinnately parted, twice palmately parted, &c. 



285. Parallel-veined or nerved leaves would naturally be ex- 

 pected to present entire margins, and this they almost universally 

 do when the nerves are convergent (Fig. 230, 243). Such leaves 

 are often lobed or cleft when the principal nerves diverge greatly, 

 as in the Dragon Arum ; but the lobes themselves are entire. 



286. There are a few terms employed in describing the apex of 

 a leaf, which may be here enumerated. When a leaf tapers to a 



FIQ. 268 -276. rormii of the apex of leaves. 

 14* 



