Chapter 4 Roots Stems and Leaves Vegetable Root
Chapter 4: Roots, Stems and Leaves Vegetable: Root, Stem, Leaf Fruit: formed because of flowers
I. Roots
A. Main Functions 1. anchor the plant 2. absorb and conduct water and minerals 3. produce hormones to regulate the plant’s growth
B. Types of Root Growth 1. Taproot system a. Taproot 1. large main root 2. functions to “tap” deep water sources b. Lateral roots 1. branches 2. result in extensive root system
2. Fibrous root system a. adventitous roots 1. arise from lower part of stem 2. not where roots usually come from b. no single root is the largest c. shallower and more horizontal than taproot system
II. Stems
A. Main Functions 1. 2. 3. Move leaves toward light and away from shade of other plants Support the weight of leaves and withstand wind Conduct water, minerals, organic molecules between roots and leaves
B. Phyllotaxy 1. 2. Greek for “Leaf Order” Leaf Arrangement a. b. c. Alternate Opposite Whorled
C. Specialized Functions 1. Stolons aka. Runners aid in reproduction
2. Rhizomes-horizontal stems underground and send up new leaves or shoots
3. Tubers- underground stems that store starch
4. Bulbs- Underground stems that store starch, contain leaf tissue
5. Corms-Underground food storage stems
III. Leaves
A. Main Functions 1. 2. Photosynthesis Transpiration a. Loss of water through pores b. Pulls water and nutrients up from the roots to the leaves
B. Specialized Functions 1. Spines-modified leaves (NOT thorns, those are modified stems)
2. Tendrils- attach a climbing plant to a supportive structure
3. Bracts- modified leaves at the base of flowers, often mistaken for petals
- Slides: 18
