INTRODUCTION. V 



Leaves which, have no stalks are termed sessile 

 (sitting), as in Eryngo, p. 255. 



A leaf which consists but of one piece is said to be 

 simple j as in Marsh Marigold, p. 16; a ternate leaf 

 consists of three leaflets on a common stalk, as in 

 Medick, p. 150 ; a quinate, of five, as in Marsh Cinque- 

 foil, p. 190. Other forms of the compound leaf axe the 

 pinnate, (from penna, a feather,) where a number of 

 leaflets are ranged along the opposite sides of a common 

 stalk, as in Saint-foin, p. 170. 



A simple leaf is sometimes wavy at the edge, as in 

 the Oak, p. 572 ; 3-, 5-, or 7-lobed, as in the Mallows, 

 pp. 112, 113; and these lobes are often deeply cut, as 

 in Geranium, p. 125. A leaf of five or more narrow 

 lobes united near the main stalk, is termed palmate, 

 (from palma, the palm of the hand,) as in Hellebore, p. 

 18. The pedate leaf differs from the palmate, in having 

 the two side lobes divided a second time at the edge 

 nearest the stalk. A leaf which is lobed after the 

 manner of a pinnate leaf, is termed pinnatifid, (from 

 penna, a feather, SLndjindo, to cleave.) 



If a stalk is attached to a leaf at or near its centre, 

 such a leaf is termed peltate, (fxompelta, a buckler,) as 

 in Cotyledon, p. 234. 



A leaf through which a stalk passes is termed per- 

 foliate, (from per, through, and folium, a leaf,) as in 

 Hare's-ear, p. 267. 



Two leaves united by their bases, and allowing the 

 stem to pass through them, are termed connate, (from con, 

 together, and nascor, to grow,) as in Chlora, p. 418. 



The margin of the leaf is either entire, as in Soap- 

 wort, p. 93 ; crenate, as in Marsh Pennywort, p. 253 ; 

 serrate (saw-edged), as in Bose, p. 201 ; toothed, as in 

 Enchanter's Nightshade, p. 214; or fringed, as in 

 Rock-rose, p. 74. 



With respect to form, the varieties of leaves are very 

 numerous, and the terms employed to define them not 

 less so. Those which occur in this volume are : 



