Join Date: Sep 2017
Lyster H. Dewey - " Botanical Study of Hemp " 1913
The hemp plant, Cannabis sativa L., is an annual, growing each year from the seed. It has a rigid, herbaceous stalk, attaining a height of 1 to 5 meters (3 to 16 ft), obtusely 4-cornered, more or less fluted or channeled, and with well-marked nodes at intervals of 10 to 50 cm (4 to 20 in). When not crowded it has numerous spreading branches, and the central stalk attains a thickness of 3 to 6 cm (1 to 2 in), with a rough bark near the base. If crowded, as when sown broadcast for fiber, the fluted stems are without branches or foliage except at the top or on the shortened branches, appearing fascicled, are palmately compound and composed of 5 to 11 --- usually 7 --- leaflets. The leaflets are dark green, lighter below, lanceolate, pointed at both ends, serrate, 5 to 15 cm (2 to 6 in) long, and 1 to 2 cm (3/8 to 3/4 in) wide. Hemp is dioecious, the staminate or pollen-bearing flowers and the pistillate or seed-producing flowers being borne on separate plants. The staminate plants are borne in small axillary panicles, and consists of five greenish yellow or purplish sepals opening wide at maturity and disclosing five stamens which discharge abundant yellow pollen. The pistillate flowers are stemless and solitary in the axils of the small leaves near the ends of the branches, often crowded so as to appear like a thin spike. The pistillate flower is inconspicuous, consisting of a thin, entire, green calyx, pointed, with a slit at one side, but remaining nearly closed over the ovary and merely permitting the two small stigmas to protrude at the apex. The ovary is one seeded, developing into a smooth, compressed or nearly spherical achene (the "seed"), 2.5 to 4 mm (1/10 to 3/16 in) thick and 3 to 6 mm (1/8 to 1/4 in) long, from dark gray to light brown in color and mottled, The seeds cleaned for market nearly always include some still covered with green, gummy calyx. The seeds vary in weight from 0.008 to 0.027 gram, the dark-colored seeds being generally much heavier than the light-colored seeds of the same sample. The light-colored seeds are often imperfectly developed. Dark-colored and distinctly mottled seeds are generally preferred. The staminate plants are often called the flowering hemp, since the pistillate flowers are rarely observed. The staminate plants die after the pollen is shed, but the pistillate plants remain alive and green two months later, or until the seeds fully developed.
The hemp stalk is hollow, and in the best fiber-producing types the hollow space occupies at least one-half the diameter. The hollow space is widest, or the surrounding shell thinnest, about midway between the base and the top of the plant. The woody shell is thickened at each node, dividing the hollow space into a series of partly separated compartments. If the stalk is cut crosswise a layer of pith, or thin-walled tissue, is found next to the hollow center, and outside of this a layer of wood composed of hard, thick-walled cells. This layer, which forms the "hurds", is a very thin shell in the best fiber-producing varieties. It extends clear across the stem below the lowest node, and in large, coarse stalks grown in the open it is much thicker and the central hollow relatively smaller. Outside of the hard woody portion is the soft cambium, or growing tissue, the cells of which develop into the wood on the inside, or into the bast and the bark on the outside. It is chiefly through this cambium layer that the fiber-bearing bast splits away from the wood in the processes of retting and breaking. Outside of this cambium is the inner bark, or bast, comprising short, thin-walled cells filled with chlorophyll, giving it a green color, and long thick-walled cells, making the bast fibers. These bast fibers are of two kinds, the smaller ones (secondary bast fibers) toward the inner portion making up rather short, fine fibers, many of which adhere to the wood or hurds when the hemp is broken, and the coarser ones (primary bast fibers) toward the outer part, extending nearly throughout the length of the stalk. Outside of the primary bast fiber is a continuation of the thin-walled stalk, chlorophyll-bearing cells free from fiber, and surrounding all is the thin bark.
The hemp fiber of commerce is composed of the primary bast fibers, with some adherent bark and also some secondary bast fiber. The bast fibers consist of numerous long, overlapping, thick-walled cells with long, tapering ends. The individual cells, almost too small to be seen by the unaided eye, are 0.015 to 0.05 mm (3/1000 to 12/1000 in) in diameter, and 5 to 55 mm (3/6 to 2-1/8 in) long. Some of the bast fibers extend through the length of the stalk, but some are branched, and some terminate at each node. They are weakest at the nodes.
Last edited by Kankakee; 02-25-2018 at 02:11 AM..