32 OBJECT LESSONS IN BOTANY. 
Fag. 76. Potentilla anserina; leaf with five cut lobes, almost quinate. 
Fig. 77. Potentilla tridentata; ternate, with palmate, three-toothed leaflets 
Fig. 78. Jeffersonia diphylla; a binate leaf. 
Fig. 79, Lemon ; a simple leaf jointed to the petiole. 
LESSON VIII. 
SESSILE LEAVES—FORMS OF STIPULES. 
41. Wn have already stated (Lesson I, § 5) that many 
leaves are without petioles (foot-stalks), or, in other words, are 
sessile. The figures presented on page 33 exhibit some of the 
modes of attachment peculiar to sessile leaves. In Fig. 80 
(an Aster) you see leaves of the form called spatulate (Lesson 
TII., § 5), having large base lobes nearly clasping the stem 
at the point of attachment. Such leaves are said to be am- 
plewicaul (stem-clasping). 
42. In the next figure (81, Bellwort) the leaves are ellipti- 
cal, parallel-veined, and not only clasp the stem at base, but 
the lobes there grow together on the opposite side, appearing 
as if the stem passed through the leaf; that is, perfoliate. 
40. What kind of venation have all these forms? On the palmate vena 
tion what forms are founded ? 
41. When are leaves said to be sessile? Define an amplexicaul leaf. 
42. Can you define a perfoliate leaf? 
