. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. THE LEAF. 31. (Fig. 34), If the leaf is folded like a fan ( Maple) it is said to be plicate, or plaited. It is circinate ( Ferns) when rolled from the tip downwards (Fig. 35); con- volute ( Plum) when rolled from one edge into a coil (Fig. 36); when rolled from both edges inwards ( Violet) it is involute (Fig. 37); when rolled outwards ( Azalea) it is revolute (Fig. 38). 34. A leaf may have
. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. THE LEAF. 31. (Fig. 34), If the leaf is folded like a fan ( Maple) it is said to be plicate, or plaited. It is circinate ( Ferns) when rolled from the tip downwards (Fig. 35); con- volute ( Plum) when rolled from one edge into a coil (Fig. 36); when rolled from both edges inwards ( Violet) it is involute (Fig. 37); when rolled outwards ( Azalea) it is revolute (Fig. 38). 34. A leaf may have three parts, namely: the blade, or lamina, which is the expanded portion (Fig. 39, hi); the petiole (Fig. 39, pet), which is the stem of the leaf; and stipules, which are the appendages at the base of the petiole (Fig. 39, stip). The stipules are very often want- ing, in which case the leaf is said to be exstipulate. If the blade is inserted directly on the stem (which is the case when the petiole is absent), the leaf is said to be sessile. The blade consists of a net-work of veins or skeleton . of woody tissue, and the soft, green tissue -Ji. between the veins called parenchyma (Gr. para, by; enchein, to fill in). When one vein surpasses the others in size it is called the midrib (Fig. 39, ); its branches are the veins (Fig. 39, vn), and the branches from the veins are the veinlets (Fig. 39, vnl). 35. If the venation of a large number Figs. 34-38. Vernation: 34. Conduplicate; 35. Circinate; 36. Convolute; 37. Involute; 38. Revolute. Fig. 39. A leaf: 6i, blade; ^^/, petiole; siip, stipules; m,r., midrib; vn, veins; vnl, veinlets; tff, apex. vn. JjUI>. 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 Kellerman, William Ashbrook, 1850-1908. Philadelphia, J. E. Potter and Company
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1883
