. The elements of structural botany [microform] : with special reference to the study of Canadian plants, to which is added a selection of examination papers. Plant anatomy; Botany; Plantes; Botanique. 72 ELEMENTS 01' STKl ( TUKAL BOTANY. Il'lil. of tlie leaf. The loaf of the Mallow is simple ; tliat of tho Clover is compound. Between the siuijjle aiul the compouinl form there is every possihle shade of gradation. In the Mallow leaf the hilux arc not very clearly defJuod. In the Maple i^Kig. lOH) they are well-marked. In other cases, again, the lobes are so nearly separate, fcliat '^ '' ^ ' Fi
. The elements of structural botany [microform] : with special reference to the study of Canadian plants, to which is added a selection of examination papers. Plant anatomy; Botany; Plantes; Botanique. 72 ELEMENTS 01' STKl ( TUKAL BOTANY. Il'lil. of tlie leaf. The loaf of the Mallow is simple ; tliat of tho Clover is compound. Between the siuijjle aiul the compouinl form there is every possihle shade of gradation. In the Mallow leaf the hilux arc not very clearly defJuod. In the Maple i^Kig. lOH) they are well-marked. In other cases, again, the lobes are so nearly separate, fcliat '^ '' ^ ' FiR. 108. the leaves appear at lirst sight to be really compound. 101. You will remember that in our examinations of dicotyledonous plants, we found the leaves to be in- variably net-veined. But, though they have this gener- al character in common, they differ considerably in the details of their veining, or venation, as it is called. The two leaves emj^^>loyed as illustrations v" the last section will serve to illustrate our meaning here. In the Mallow, there are several ribs of about the same size, radiating from the end of the pijtio.'e something like the spread-oat lingers of a hand. The veining in this case is therefore described as diijilntc, or radutte, or palmate. The leajUu of the clover, on the other hand, is divided exactly in the middle by a single rib (the midrib), and from this the veins are given oif on each Side, so that the veining, on tlio whole, presents tho appearance of a featlier, and is therefore described as pinnate [petuui, a feather). 102. Both simple and compound leaves exhibit these two modes of venation. Of simple pinnately-veined. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Macoun, John, 1831-1920; Spotton, H. B. (Henry Byron), 1844-1933. Toronto : W. J. Gage
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, booksubjectpl
