ta : - ye ae Be VY eg can kik ee ed ee a ee ne eee ~ DRO Oe eae 
. . at ee 
coy Pe a 
pire AMEE oe 1 PSs, Spare eheat 5 ates Bare Conn nae OU A Se ae 
92 Structural and Physiological Botany. = 
stem itself as in the wood-vetch, Vicca sepium, when | they 
are decurrent, and give a winged appearance, sometimes to 
the petiole, sometimes to the stem. [When not adherent to 
the petiole they are said to be /vee.] The stipules are mostly 
smaller than the true leaves, seldom larger, as in the pansy 
(Fig. 144). In Lathyrus Aphaca (Fig. 146), the stipules of 
Fic. 146.—Lathyrus Aphaca; r tendril; Fic. 147.—Leaf of grass ; Lg. ligule; _ 
b flower ; / fruit ; 7 stipule. L lamina ; G leaf-sheath. 
the upper leaves are the only part to expand, the leaf itself 
degenerating into a tendril. The stipules of the gooseberry - 
-and common ‘acacia,’ Robinia pseudacacta (Fig. 184, p. 103), 
--are spinous ; they are leaf-like and persistent in the pea, 
membranous and deciduous in the oak and beech.! Under 
the head of stipules come the /ewles (Figs. 142, 147), or 
delicate appendages which grow at the point of union of 
lamina and sheath in the leaves of grasses. 
Sessile leaves sometimes partly or entirely embrace the 
stem, and are then amp/lexicaul, or semi-amplexicaul. In the 
former case the base is occasionally developed in a sheath-like 
1 [In pinnate leaves, each of the petiolules or separate petioles 
of the leaflets is sometimes furnished at its base with a secondary sti- os 
pule or stzpella. —ED. ] : 
