1. Plant Science Stems

2. Stems Stems Stems The main stem and branches are the scaffolding of The main stem and branches are the scaffolding of the plant Supports the leaves, flowers and fruits transport water, nutrients, sugars through capillary action store food

3. Above ground stem types Woody and Herbaceous Woody and Herbaceous Woody stems Woody stems Tough and winter hardy Tough and winter hardy Often have bark around them Often have bark around them Herbaceous Stems Herbaceous Stems More succulent More succulent Often green Often green Do not survive in cold climates Do not survive in cold climates

4. Modified stems Bulbs, corms, rhizomes and Tubers Bulbs, corms, rhizomes and Tubers Bulbs Bulbs Highly compressed underground stems Highly compressed underground stems Have modified leaves called scales Have modified leaves called scales

5. Corms Corms Thickened, compact, fleshly stems Thickened, compact, fleshly stems

6. Rhizomes Rhizomes Run just under the surface Run just under the surface A new plant will group where each node is A new plant will group where each node is

7. Tubers Tubers Thickened underground stems that store carbohydrates Thickened underground stems that store carbohydrates

8. Parts of the stem Node Node Internode Internode Axillary Bud Axillary Bud Axil Axil Lenticels Lenticels Terminal Bud Terminal Bud Vegetative Bud Vegetative Bud Flowering Bud Flowering Bud

9. Node: swollen part of stem where buds form (leaves or stems grow here) Internode: stem tissue between nodes

10. Axillary bud – a bud formed in the axil of a leaf Axillary bud – a bud formed in the axil of a leaf Axil- the angle on the upper side of the union of a branch and main stem of a leaf and stem Axil- the angle on the upper side of the union of a branch and main stem of a leaf and stem

11. Lenticels – an opening made up of loosely arranged cells in the stem to allow for passage of gases Lenticels – an opening made up of loosely arranged cells in the stem to allow for passage of gases

12. Terminal Bud – a bud at the end of the stem Vegetative Bud – a terminal plant bud that produces a stem and leaf growth Flowering Bud - a terminal plant bud that produced a flower

13. Internal parts of stem Phloem Phloem Xylem Xylem Cambium Cambium Pith Pith Cortex Cortex

14. Functions Phloem-Sugar and carbohydrates to roots Phloem-Sugar and carbohydrates to roots Xylem- Water and nutrients Xylem- Water and nutrients Cambium- Growing part of stem Cambium- Growing part of stem

15. Pith-Occupies the central area of the stem Pith-Occupies the central area of the stem Cortex- Composed of several layers of thick-walled cells Cortex- Composed of several layers of thick-walled cells