. Class-book of botany : being outlines of the structure, physiology, and classification of plants ; with a flora of the United States and Canada . Botany; Botany; Botany. FORM OR FIODRE. S5 of individual forms of outline we ahall select. only the most remarkable, leaving others for explanation in the glossary. 264. The most obvious akrakqement is that whioh is founded upon the modes of veining; but it should be. premised that different forms of venation often give rise to the same outline. Were we required to characterize our idea of the abstrac't, typical leaf-form, we should sketch an oval
. Class-book of botany : being outlines of the structure, physiology, and classification of plants ; with a flora of the United States and Canada . Botany; Botany; Botany. FORM OR FIODRE. S5 of individual forms of outline we ahall select. only the most remarkable, leaving others for explanation in the glossary. 264. The most obvious akrakqement is that whioh is founded upon the modes of veining; but it should be. premised that different forms of venation often give rise to the same outline. Were we required to characterize our idea of the abstrac't, typical leaf-form, we should sketch an oval outline of surface, with equal aides and! anequal ends. The nearest approach to this we find among the 121 122 125. Diagrams of pinnate-veined leaf-forms. 119, orbicular, 120, oval. 121, elliptical, 122, oblong, 123, cuneiform. 124, spathulato, , 125, oblanceolato, 126, oboTflte, 127, deltoid, 123, lanceolate, 129, ovate. LEAVES. Of these, the follov/ing forms depend upon the length of the veinlets in relation to each other and to the midvein. When the loioer veinlets are loni/er than the others, the form of the blade will be (1) ovate, with the out- line of an egg, the broad end at the base ; (2) lanceolate, or lance- shaped, narrower than ovate, tapering gradually upwards; (3) deltoid or triangular shaped, like the Greek letter A. a. If the middle veinlets exceed the others in length, the leaf will be (4) orbicular, roundish or quite circular; (5) elliptical, with tlie outline of an ellipse, nearly twice longer than broad; (6) oval, broadly elliptical; (V) oblong, narrowly elliptical. 266. When the veinlets ake more lakgelt developed in the UPPER region of the LEAF its form becomes (8) obavate, inversely ovate, the narrow end at base; (9) ohlanceolate, that is, lanceolate with the narrow end at base; (10) spatulate, like a spatula, with a narrow base and a broader, rounded apex; (11) cuneate or cuneiform, shaped like a wedge with the point backwards. 267.
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Keywords: ., bookcentury1800, bookdecade1860, bookpublisher, booksubjectbotany
