Text-book of botany; morphological and physiological
Julius Sachs
Paperback
(RareBooksClub.com, March 6, 2012)
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1882 Excerpt: ...the shoot within the bud is so densely covered with the bases of leaves that no free portion of the surface of the axis is visible between them. When the axis has attained a considerable length on the unfolding of the bud, the bases of the leaves generally grow at the same time in length and breadth, so that they entirely cover the surface of the enlarged shoot also, clothing it wiih a green cortex, in which the parts belonging to the separate leaves can be distinctly recognised. This is especially clear in Araucaria and many species of Pinus, but is very common also in other genera; in Thuja, Cupressus, Libocedrus, &c, the axis of the shoot is also completely covered with these leaf-cushions; but the free parts of the leaves are very small and often project only as short points or projections. The phyllotaxis is spiral in the Abietineae, Taxineae, Araucariex, Podocarpus, &c.; the Cupressineae bear whorls which, above the cotyledons, contain generally from three to five leaves, but usually fewer at a greater height on the primary axis. The secondary axes usually begin at once with decussate pairs, which, in bilateral shoots, are alternately larger and smaller (as in Callitris and Libocedrus); in Juniperus and Frenela the whorls on the secondary axes also consist of from three to five leaves, and are alternate; the pairs of leaves of Dammara stand at an acute angle to one another. The foliageleaves of most Conifers are very persistent, and may live for several years, their leafcushions keeping pace in growth for a long time with the increase in size of the axis; in Larix and Salisburia the leaves alone are deciduous in autumn, in Taxodium distichum the axes that bear them are also deciduous. The Flowers of Coniferae are always diclinous; either monoe...