FIG. 103-111. Forms of the apex of leaves.
Text and Figures from Gray's Lessons in Botany and Vegetable Physiology, p 60. 1
FIG. 103-111. Forms of the apex of leaves.
153. As to the Apex, the following terms express the principal variations.
Acuminate, pointed, or taper-pointed, when the summit is more or less prolonged into a narrowed or tapering point, as in Fig. 97.
Acute, when ending in an acute angle or not prolonged point, as in Fig. 104, 98, 95, etc.
Obtuse, when with a blunt or rounded point" as in Fig. 105, 89, etc.
Truncate, with the end as if cut off square, as in Fig. 106, 94.
Retuse, with the rounded summit slightly indented, forming a very shallow notch, as in Fig. 107.
Emarginate, or notched, indented at the end more decidedly, as in Fig. 108.
Obcordatc, that is, inversely heart-shaped, where an obvate leaf is more deeply notched. at the end (Fig.l09), as in White Clover and Wood-sorrel; ; so as to resemble a cordate leaf (Fig.99) inverted.
Cuspidate, tipped with a sharp and rigid point; as in Fig. 110.
Mucronate, abruptly tipped with a small and short point, like a projection of the midrib; as in Fig. 111.
Aristate, awn-pointed, and bristle-pointed, are terms used when this mucronate point is extended into a longer bristle-form or other slender appendage.
The first six of these terns can be applied to the lower as well as to the upper end of a leaf or otherother organ. The others belong to the apex. only.
1. Asa Gray 1880. Gray's Lessons in Botany and Vegetable Physiology Vision, Blakman, Taylor & Co., New York and Chicago.