100 



STRUCTURAL BOTANY. 



to the depth of the incisions as above described. But the most 

 peculiar modification is the Pedate, like a bird's foot, having the 

 lowest pair of veins enlarged, recurved, 

 and bearing each several of the seg- 

 ments (348). 



297. The forms of the parallel- 

 veined leaves are remarkable for their 

 oven, flowing outlines, diversified solely 

 by the direction and curvature of the 

 veins. When the veins are straight, the 

 most common form is the Linear, long 

 and narrow, with parallel margins, like 

 the leaves of the Grasses a form which 

 may also occur in the pinnate-veined 

 leaf, when the veinlets are all equally 

 shortened. The ensiform, or sword- 

 shaped, is also linear, but has its edges 

 vortical, that is, directed upward and 

 downward. 



298. If the veins curve, we may have 

 the lanceolate, elliptical, or even orbicu- 

 lar forms ; and if the lower curve down- 

 ward, the cordate, sagittate, etc. Pal- 

 mate forms there also are, splendidly 

 developed in the Palmetto and other 



Sol, Ensiftirin leaves of Iris. 352, 

 T'olmc ixrVmcp Inro-p IPHVP nrp nvmrrmri Acerose leaves of Pinns. 353, Subu- 



i aims, wm e laige ica'ves aie appropu- 1}tte leaves o( j lU n pe nis communis. 

 ately Ctolled-jZabelltform (fan-shaped). 



299. The leaves of the Pine and the Fir tribe (Coniferie) gen- 

 erally are parallel-veined also, and remarkable for their con 

 tracted forms, in which there is no distinction of petiole or blade. 

 Such are the Acerose (needle-shaped) leaves of the Pine, the 

 tubulate (awl-shaped) and scale-form leaves of the Cedars, etc. 



Review. %S1. Account for the leafs figure. What the principle of our classification ? 

 28S, Of feather-veined forms, define the first class. Define each special form. 28!). The 

 eeopnd class. Each special form. 290. The third class. Define an obovate leaf An ob- 

 lanceolate A spatulate A cuneate. 291. Define the fourth class. Distinguish four spe- 

 cial forms. Apply the proper term to each figure (311-319). 29-2. On what do the pinna- 

 tifid forms depend ? Describe the pinnatifid leaf The runcinate The lyrate. 294. What 

 is pinnately-parted ? Sinuate ? 295. What forms may a palmi-veined loaf take ? Define 

 reniform Peltate. Observe (fisr. 347-350) which is palmately cleft Parted -Lobcd. De- 

 fine pedate. 297. What is remarked of the parallel-veined leaves? Examples of tha 

 linear Ensiform Acerose Flabclliform Subulate. 



