THE LEAVES. 



21 



Stipules are foliaceous (s. foliacece), when of the colour and texture of leaves 

 (Heartsease, fig. 60) ; scale-like (s. squamiformes), when thin like scales ; mem- 

 branous (s. membranacece] , when thin, flexible, and almost transparent ; scarious 

 (s. scariosce], when dry and coriaceous (Beech, Willow, Hornbeam) ; spinous 

 (s. spinosce), when contracted and hardened into spines (Robinia, fig. 114) ; cirrhose 

 (s. cirr~kiform.es), when they lengthen into twining tendrils (Melon, fig. 61). (We 

 retain the name of stipules for the tendrils of the Melon and other Cucurbitacece, in 

 deference to the glossology adopted by botanists ; but we shall return to this 

 subject when discussing tendrils. 



Stipules are lateral (s. laterales], when inserted left and right of the leaf (Hearts- 

 ease, fig. 60; Robinia, fig. 114); axillary (s. axillares), when in the axil of the 

 leaf; they are then usually consolidated into one. Such axillary stipules may 

 cover only a part of the circumference of the stem (Drosera], or may completely 

 surround it (Buckivheat, fig. 62), in which latter case.it bears the name of ochrea. 



The ligule of grasses (ligula, Meadoiv-grass, fig. 63) is simply an axillary stipule 

 (Lig.), situated at the separation of the blade (L) from the sheathing petiole (G) ; 

 it may be entire, emarginate, laciniate, pilose, &c. 



Of the whorled leaves of Madder (fig. 4) and other Rubiacece, the two opposite 

 ones are alone considered as true leaves, and bear each a bud in its axil ; the others 

 are regarded as stipules, sometimes multiplied, when there are more than four, or 

 confluent, when fewer than four. 



The Nerves of the leaf are said to be parallel (n. paralleli), when they run free 

 and parallel to the edge of the leaf and to each other (Iris, figs. 33, 79) ; branching 

 or anastomosing (n. ramosi, anastomosantes) , when they subdivide and join each other 



(Cherry, fig. 6). 



Branching nerves are pinnate (n.pinnati], and 

 the leaves penni-nerved* (f. penni-nervia], when 

 lateral nerves, like the plumes of a feather, spring 

 from the midrib (Cherry, fig. 6) ; palmate (n. pal- 

 mati, palmatinervia), when several primary nerves 

 diverge from the base of the blade like the 

 fingers of a hand (Melon, fig. 64). The primary 

 nerves only are palmate ; the secondary, tertiary, 

 &c., are always pinnately arranged. 



As regards position, leaves are radical (f. radi-r 

 calia], when they spring from near the neck, 

 and hence appear to rise from the root (Dandelion, 

 fig. 29 ; Plantain, Erophila, fig\ 65) ; cauline 

 (f. caulina], when they spring from the stem and 

 branches (Rose, fig. 50). Leaves are clasping or 

 amplexicaul (f. amplexicaulia], when the base of 

 their petiole or blade surrounds the stem (Butter- 

 cup, Henbane); decurrent (f. decurrentia] , when 

 their blade is continued down the stem, forming a sort of foliaceous wing ; 



69. Yew. Distichous leaves. 



70. Fascicled 



leaves. 



