Biol 324 Introduction To Seed Plant Taxonomy
Biol 324 Course topics
Roots as sources of taxonomic characters
- Roots scarcely used by taxonomists - hidden underground!
- Useful or for identification in some groups: Delphinium and Lomatium
- Unlike stems, no regularly spaced organs: branch irregularly, but may produce adventitious buds, which can grow into stems.
Monocot vs Eudicot roots
They differ in their root anatomy. Eudicots have a star-shaped solid core of xylem, with phloem between the arms of xylem. Monocots have separate alternating bundles of xylem and phloem
The major types of roots:
- Adventitious - arising from an organ other than a root, such as a stem.
- Primary - the first root of a seedling, from the radicle of the embryo. It is the tip of the main axis of the plant. If it is persistent and well developed it is called a TAP ROOT.
- Secondary - roots branching from the primary or other secondary roots.
- Fibrous roots - a fine, slender root system without a tap root.
- Tuberous roots are fleshy, swollen roots, such as a carrot, which resemble tubers. True tubers are stem tissue.