Plant Genealogy and Taxonomy Notes Know underlined terms I. NON-VASCULAR PLANTS: • Algae, mosses • First to evolve on earth (about 470 million years ago). No special vessel-like system for transmission of fluids. II. VASCULAR PLANTS: A plant’s “circulatory system” • Special vessel-like system for transmission of fluids: • A. Non-Seed Bearing (spores): • EX: Ferns Evolved about 400 mya. II. VASCULAR PLANTS: • B. Seed-bearing: • 1. Gymnosperms “naked-seed” (no fruit). Evolved ˜ 360 mya: • male/ female parts; disperse, collect pollen; form seeds • EX: Conifers (pines, redwoods, etc.) II. VASCULAR PLANTS: • B. Seed-bearing: • 2. Angiosperms “covered seeds”; flowering plants (fruit). Evolved ˜180 mya. • male/ female parts in flower; disperse, collect pollen; form fruits and seeds II. VASCULAR PLANTS: Where seed stores food --like an egg’s yolk. • 2. Angiosperms: • a. Monocots (1 cotyledon [1 seed lobe], parallel leaf veins): • EX: Grasses, corn II. VASCULAR PLANTS: • 2. Angiosperms: • b. Dicots (2 cotyledons [2 seed lobes], networked leaf veins): • EX: most other spp. II. VASCULAR PLANTS: • 3. Other descriptions of vascular plants (may be gymnosperms or angiosperms, monocots or dicots): • Annuals: Plants that complete their lifecycle in a year or less (go to seed every year) • Perennials: Plant that lives for more than 2 years. Quic kTime™ and a TIFF ( Unc ompres s ed) dec ompres s or are needed to s ee this pic tur e. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. III. PLANT EVOLUTION • Consider the power and role of evolution in plant genealogy: • A. Background: What is evolution? • Cumulative changes in a population as a result of: • 1. appearance of variation in a population (often caused by mutation), • 2. a selective force that selects for or against the survival of certain individuals in the population • 3. reproduction: passing on of the selected characteristic that allowed for survival. III. PLANT EVOLUTION • B. Where did flowers come from (what is the source of variation in the plant population)? • Modified/ adapted leaf structures. • C. Why were flowers selected? • Sexual reproduction increases variation--vital to evolutionary process. Flowers are a means of sexual reproduction.