The shoot includes the
stem, branches, leaves,
fl owers, and fruits (Fig.
23.3). The shoot of a hemp plant, for example, can be 10 to 20 feet (3 to 6 m) tall. The stem, a stiff bundle of internal transport tubes plus surrounding tissues, supports the rest of the shoot. The stem is enclosed within an external waterproof coating that minimizes water loss. Hemp stems are only about an inch in diameter despite their very tall height. In trees and shrubs, the main stem matures into a large, woody, barkcovered
trunk with many side branches supporting thousands of leaves and
flowers.

[HS]

Fiber Types
Total fiber content is approximately 25-35 percent of
stem dry matter, depending on variety.
1. Primary bast fiber - long and low in lignin
2. Secondary bast - intermediate and high in lignin
3. Libriform - short and high in lignin
Hemp fiber has been valued is because of its length. The inner portion of the stem contains the hurd, which is used for paper and building materials. The primary bast fibers in the bark are 5–40 mm long, and are amalgamated in fiber bundles which can be 1–5 m long (secondary bast fibers are about 2 mm long). The woody core fibers are short—about 0.55 mm—and like hardwood fibers are cemented together with considerable lignin. The core fibers are generally considered too short for high grade paper applications (a length of 3 mm is considered ideal), and too much lignin is present.

Hemp Structures