Trees; a handbook of forest-botany for the woodlands and the laboratory . majority of cases. Another difficulty for the beginner resides in leaveswhich are so lobed, or divided into segments, at themargins, that he hesitates how to begin the rule is to suppose a contour line drawn so as toinclude the base and apex, and touch the tips of all thelobes. In most cases a figure perfectly describable in n] LEAF-MARGIN 27 terms such as I have enumerated will be obtained, and thefurther analysis can be attempted. In compound leaves, the terms referred to are appliedto the leaflet. A nu
Trees; a handbook of forest-botany for the woodlands and the laboratory . majority of cases. Another difficulty for the beginner resides in leaveswhich are so lobed, or divided into segments, at themargins, that he hesitates how to begin the rule is to suppose a contour line drawn so as toinclude the base and apex, and touch the tips of all thelobes. In most cases a figure perfectly describable in n] LEAF-MARGIN 27 terms such as I have enumerated will be obtained, and thefurther analysis can be attempted. In compound leaves, the terms referred to are appliedto the leaflet. A number of other useful terms will be employedas we proceed, and their explanation is given in theglossary. But we rarely find that the circumscription of a leafwould accurately describe its shape in terms of the abovefigures only, and the margin and apex especially usuallyneed additional description. The margin (Fig. 9), if unbroken, is termed entire (1);but it is more commonly serrate (2), dentate (3), crenate (4),sinuate (5), or cut (7) in various degrees ; the serrate. Fig. 9. Margins of leaves. 1 entire; 2 serrate; 3 dentate; 4 crenate;5 sinuate; 6 bi-serrate; 7 cut or lubed. margin being very common, and defined by the saw-liketeeth pointing forwards. When the serrate teeth areagain serrate, as in Fig. 9 (6), the term bi-serrate is apex (Fig. 10) may be bluntly rounded, or obtuse (1),or pointed in various ways— acuminate (2), or merelyacute (3), or mucronate (4), or retuse (5), all of which occurmore or less commonly 28 LEAF-APEX, ETC. [CH. The art of describing a leaf well and accurately de-pends on the judicious use of such terms as the above,especially in combination— ovate-lanceolate, linear-oblong—when the form approximates both of the outlines
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