viii INTRODUCTION TO BRITISH BOTANY 



A leaf through which a stalk passes is termed perfoliate (from per, 

 through, and folium, a leaf), as in Hare's-ear, p. 122. 



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, Plate 59. 



The margin of the leaf is either entire, as in Soapwort, Plate 10 ; 

 crenate, as in Marsh Pennywort, Plate 34 ; serrate (saw-edged), as 

 in Rose, Plate 29 ; toothed, as in Enchanter's Nightshade, Plate 30 ; 

 or fringed, as in Rock-rose, Plate 8. 



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 : 



Hair-like, or capillary, as in Fennel, p. 124. 

 Linear, as in the Grasses and Pink, p. 39. 

 Strap-shaped, as in Corrigiola, p. 103. 

 Oblong, as in Rock-rose, Plate 8. 



Elliptical, oval, with both ends alike, as in the leaflets of Rose, 

 Plate 29. 



Egg-shaped, oval, with the base broader than the extremity, as 

 in Pear, p. 90. 



Inversely egg-shaped, oval, with the base 

 narrower than the extremity, as in Brook weed, 

 p. 239. 



Rounded, as in Pyrola, p. 186. 

 %oA . xnr Heart-shaped, as in Violet, Plate 9. 



\( Inversely heart-shaped, as in the leaflets of 



Medick, p. 67. 



Kidney-shaped, as in Ground Ivy, Plate 71. 

 Arr 07V- shaped, as in Tower Mustard, p. 25. 

 Halberi-shaped, arrow-shaped, but with the 

 barbs turned outwards. 

 Angular, as in Danish Scurvv-Grass. 



DANISH SCURVY GRASS c J 7 x J T " t>i I t*. 



Sword-shaped, as in Ins, Plate t&^j. 



Stipules. The base of the leaf-stalk is not unfrequently fur- 

 nished with two sheathing wings ; these are called ~ 

 stipules. The leaf of the Rose has oblong stipules at f$Mz. 

 its base. 



Bracts. Beneath the flower are frequently situ-^j 

 ated small leaves called bracts. Sometimes they are 

 mere scales, as in the Broom-rape, Plate 67 ; but 

 more frequently they are only to be distinguished 

 from true leaves by their smaller size, as in Evening Primrose 

 p. 94. 



In the Umbelliferous Tribe, p. in, they often grow, several in a 

 whorl, at the base of the general and partial umbels ; and in Com- 

 pound Flowers, p. 146, they are yet more numerous at the base 



