. 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. PHTLLOTAXy, OB LEAF ARRANGEMENT. 49 231. The alder otolb. In tlie alder, birch, sedges, &c., the cycle is not com- plete until the fourth leaf is reached. The fourth leaf stands over the iirst, the fifth over the second, &c., forming three vertical rows. Here call the cycle i; 1 denotes the turns, 3 the leaves, and this fraotion itself the angular distance (i of 360°). 232. The cherry otclb. In the cherry, apple, pe
. 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. PHTLLOTAXy, OB LEAF ARRANGEMENT. 49 231. The alder otolb. In tlie alder, birch, sedges, &c., the cycle is not com- plete until the fourth leaf is reached. The fourth leaf stands over the iirst, the fifth over the second, &c., forming three vertical rows. Here call the cycle i; 1 denotes the turns, 3 the leaves, and this fraotion itself the angular distance (i of 360°). 232. The cherry otclb. In the cherry, apple, peach, oak, willow, etc., neither the third nor the fourth leaf, but the sixth, stands over the first; and in order to reach it the thread makes two turns around the stem. The sixth leaf is over the cycle; 2 denotes the turns, 5 the leaves in the cycle, and the fraction itself the an- gular distance (| of 360°). 233. The Osage-oransb cycle. In the common hedge plant, Osage-orange, the holly, evening primrose, flax, etc., we find no leaf exactly over the fii'st until -ne come to the 9th, and in reaching it the spiral makes three turns. Here the leaves form eight vertical rows. It is a f cycle ; 3 the number of turns, 8 the number of leaves, and the fraction the angular distance ijetween the leaves (â¢Â§â of 360°). 234. The cycles compared. These several fractions which represent the above cycles form a series as follows: .}, -J-, |, |, in which each term is the sum of the two preceding. The fifth terms in order will, therefore, be J^; and this arrangement ia actually realized in. 96, Phyllotaxy of the cone (cycle J-,) of Pinus 9T, cherry cycle (f), as seen from above, forming necessarily that kind of (estivation called quincuntial. 235. The white pms cycle. In the young shoots of the white pine, in oones of most pines, in flea-bane (Erigeron Ganadense), etc., the fourteenth leaf stands over the first, the fifteenth over the second, etc. The spiral thread m
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