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TEXTBOOK OF BOTANY 



Fig. 17. Forms of leaves. Upper row — forms of leaf blades: A, linear; B, lanceo- 

 late; C, spatulate; D, ovate; E, obovate; F, oblong; G, cordate; H, orbiculate; 

 I, peltate. 



Second row — forms of leaf margins: A, entire; B, serrate; C, doubly serrate; 

 D, dentate; E, crenate; F, undulate; G, pinnately lobed; H, palmately lobed. 



Third row — forms of apexes of blades: A, acute; B, acuminate; G, obtuse; 

 D, aristate; E, mucronate; F, refuse; G, truncate. 



Lower row — forms of bases of blades: H, rounded; I, equally lobed; J, obliquely 

 lobed; K, acute; L, acuminate; M, sagittate; N, hastate. 



There are several types of spiral arrangement of alternate leaves. If 

 the spiral runs halfway round the stem in passing from one node to the 

 next, as in elm or corn, the arrangement is described as 1/2 alternate. 

 This arrangement is called two-ranked because the points of attachment 

 of the leaves appear in two ranks, one on either side of the stem when 

 the stem is viewed endwise. If leaves are attached at angles of 120° — 



