. Botany of the living plant. Botany. CONIFERAE : THE SCOTS PINE 307 The chief comparative interest of such a plant as the Scots Pine Has not so much in the form and structure of the sporophyte-plant, as in the details of its propagation. This is carried out, as in the Angiosperms, by organs grouped as Flowers, which are male or female. In the Scots Pine these may be borne on the same tree, though often on distinct branches. The female flower, pink and succulent at pollination, matures into the hard woody coiie, from which the name. Fig. 249. Radial section of Pine stem, at the junction of woo
. Botany of the living plant. Botany. CONIFERAE : THE SCOTS PINE 307 The chief comparative interest of such a plant as the Scots Pine Has not so much in the form and structure of the sporophyte-plant, as in the details of its propagation. This is carried out, as in the Angiosperms, by organs grouped as Flowers, which are male or female. In the Scots Pine these may be borne on the same tree, though often on distinct branches. The female flower, pink and succulent at pollination, matures into the hard woody coiie, from which the name. Fig. 249. Radial section of Pine stem, at the junction of wood and bast. Pliloem to the left, xylem to the right. s = autuinn tracheides. / = bordered pits. c = cambium. y = sieve-tubes. i'i = sieve pits, /m —tracheidal medullary ray cells. sm = medullar>' ray cells in the wood containing starch. SM!' = the same in the bast. £Hi —meduilarv ray cells w-ith albuminous content. ( x 2+0.) (.\fter Strasburger.) Coniferae is derived (see Fig. 246, p. 304). When ripe it consists of a central axis bearing in a complex spiral numerous woody ovuliferous scales. As the cone ripens the scales turn back, and two seeds may be seen freely exposed on the upper surface of each. When fully ripe each seed separates from the scale, together with a thin film of superficial tissue, which on detachment helps to float it away on the breeze. The seed is protected by a seed-coat, covering a bulky endosperm, with a large embryo enclosed in it, which has many cotyledons, plumule and radicle. The seed is thus " albuminous,". 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 Bower, F. O. (Frederick Orpen), 1855-1948. London, Macmillan and co. , limited
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
