Biology 2217B Lecture Notes - Lecture 11: Fertile Crescent, Ligule, Poaceae
13 Jul 2019
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Document Summary
The most important group of plants to humankind. Historic significance: ceres, the goddess of grain, atop the chicago board of trade building. Sheath encloses the stem: flowers: spikelets contain one or more florets; usually subtended by glumes. Grasses (cont. : evolved in cretaceous period (~65 mya, forests to deserts, most widespread plant. 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. Alternate arrangement: both annual and perennial. Sexual reproduction in the magnoliophyta: sporophyte and gametophyte are two stages in plant life cycle, sporophyte. Diploid plant that produces spores by meiosis: gametophyte. Haploid plant that produces sperm and eggs: wind pollination of haploid gamete spores. The flower: spiked flowers in inflorescences, small and incomplete. Lodicules take place of sepals and petals. Three stamens: single ovule in ovary.
