The Elements of Botany, For Beginners and For Schools. Gray Asa
Aristate, Awn-pointed, and Bristle-pointed, are terms used when this mucronate point is extended into a longer bristle-form or slender appendage.
The first six of these terms can be applied to the lower as well as to the upper end of a leaf or other organ. The others belong to the apex only.
138. As to degree and nature of Division, there is first of all the difference between
Simple Leaves, those in which the blade is of one piece, however much it may be cut up, and
Compound Leaves, those in which the blade consists of two or more separate pieces, upon a common leaf-stalk or support. Yet between these two kinds every intermediate gradation is to be met with.
139. As to Particular Outlines of Simple Leaves (and the same applies to their separate parts), they are
Entire, when their general outline is completely filled out, so that the margin is an even line, without teeth or notches.
Serrate, or Saw-toothed, when the margin only is cut into sharp teeth, like those of a saw, and pointing forwards; as in Fig. 142.
Dentate, or Toothed, when such teeth point outwards, instead of forwards; as in Fig. 143.
Crenate, or Scalloped, when the teeth are broad and rounded; as in Fig. 144.
Repand, Undulate, or Wavy, when the margin of the leaf forms a wavy line, bending slightly inwards and outwards in succession; as in Fig. 145.
Sinuate, when the margin is more strongly sinuous or turned inwards and outwards; as in Fig. 146.
Incised, Cut, or Jagged, when the margin is cut into sharp, deep, and irregular teeth or incisions; as in Fig. 147.
Lobed, when deeply cut. Then the pieces are in a general way called Lobes. The number of the lobes is briefly expressed by the phrase two-lobed, three-lobed, five-lobed, many-lobed, etc., as the case may be.
140. When the depth and character of the lobing needs to be more particularly specified, the following terms are employed, viz.:—
Lobed, in a special sense, when the incisions do not extend deeper than about half-way between the margin and the centre of the blade, if so far, and are more or less rounded; as in the leaves of the Post-Oak, Fig. 148, and the Hepatica, Fig. 152.
Cleft, when the incisions extend half way down or more, and especially when they are sharp; as in Fig. 149, 153. And the phrases two-cleft, or, in the Latin form, bifid, three-cleft or trifid, four-cleft or quadrifid, five-cleft or quinquefid, etc., or many-cleft, in the Latin form, multifid—express the number of the Segments, or portions.
Parted, when the incisions are still deeper, but yet do not quite reach to the midrib or the base of the blade; as in Fig. 150, 154. And the terms two-parted, three-parted, etc., express the number of such divisions.
Divided, when the incisions extend quite to the midrib, as in the lower part of Fig. 151, or to the leaf-stalk, as in Fig. 155; which really makes the leaf compound. Here, using the Latin form, the leaf is said to be bisected, trisected (Fig. 155), etc., according to the number of the divisions.
Конец ознакомительного фрагмента.
Текст предоставлен ООО «ЛитРес».
Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес.
Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом.