Biology 2217B Lecture Notes - Lecture 9: Whole-Wheat Flour, Durum, Common Wheat
17 May 2013
School
Department
Course
Professor
Document Summary
Grass family is of greater importance to humanity than any other family of flowering plants. Monocots: parallel-veined leaves and flower parts which occur in multiples of three. Growth cycle: mostly perennial or annual herbs, erect stems, ascending, prostrate or creeping, round, hollow or solid at nodes or internodes. Leaves: alternate, composed of an open sheath, ligule, and blade; sheath encloses the stem. Flowers: spikelets contain one or more florets; usually subtended by glumes. Evolved in cretaceous period (about 65 million years ago) Important for humans: 10, 000 years fertile crescent. Majority of food crops, paper making, animal feed, lawns. The grass family poaceae: genera: 600 650, species: 9000 10,000. Both annual and perennial: most cereals are annuals, most pasture and lawn grasses are perennials. Culm hollow, jointed stem of grasses. Many also have horizontal stems either aboveground stolons or underground rhizomes that can propagate the plant vegetatively by giving rise to new shoots.
