. A textbook of botany for colleges and universities ... Botany. Fig. 939. — A growing shoot of the sweet pea {Lathyrus odoralus), showing leaves with a pair of leaflets (/), a terminal tendril (i), and a pair of stipules {s) at the base of the petiole. Figs. 940, 941. — Bud protec- tion in the sycamore {Platanus occidentalis): 940, a portion of a twig, showing the swollen base of a petiole; 941, a twig, as in 940, with enough cut away to show the bud for the following year (d) covered by the swollen base (i) of the petiole (p). a statement that is unwarranted, since there is no evidence that
. A textbook of botany for colleges and universities ... Botany. Fig. 939. — A growing shoot of the sweet pea {Lathyrus odoralus), showing leaves with a pair of leaflets (/), a terminal tendril (i), and a pair of stipules {s) at the base of the petiole. Figs. 940, 941. — Bud protec- tion in the sycamore {Platanus occidentalis): 940, a portion of a twig, showing the swollen base of a petiole; 941, a twig, as in 940, with enough cut away to show the bud for the following year (d) covered by the swollen base (i) of the petiole (p). a statement that is unwarranted, since there is no evidence that ancestrally they were ever anything else than tendrils. Petioles. — Attention has been called elsewhere to the chief advantage of leaf- stalks or petioles, namely, the facilitation of leaf display to light through elongation and change of orientation. Petioles are poorly developed in most conifers and monocotyls, reaching their culmination in dicotyls, where usually they are slender, elongated organs, contrasting sharply with the blades (fig. 779). Short or broad petioles are of less significance in facilitating leaf display. While many petioles are cylindrical, others are grooved and still others (as in the poplars) are flattened laterally. Some leaves (known as phyUodes) consist only of petioles (fig. 853).. 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 Coulter, John Merle, 1851-1928; Barnes, Charles Reid, 1858-1910, joint author; Cowles, Henry Chandler, 1869- joint author. New York, Cincinnati [etc] American book company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
