Raunkiaer`s classification
Raunkiaer’s classification Raunkiaer’s classification is a system published by Christen Raunkiaer in 1934 to describe plant life forms. It is based on the location of the buds on the plant and the way the resting bud survives periods of adverse conditions – like cold or drought. It is a useful way to relate plant and environmental interactions. Back to plant growth form menu Next Modified Raunkiaer classification • • • • Phanerophyte Chamaephyte Hemicryptophyte Cryptophyte • Geophyte • Helophyte • Hydrophyte • Therophyte • Epiphyte • Aerophyte Back to vegetative parts main menu Main menu Raunkiaer’s classification Phanerophytes are the woody perennials (trees and shrubs). The resting buds are > 0.5 m above ground. Phanerophytes have been further subdivided based on the size of the plants into megaphanerophytes, mesophanerophytes and nanophanerophytes. Additional modification to this class recognizes differences in deciduous and evergreen species. Back to plant growth form menu Back Next Magnolia Back to vegetative parts main menu Main menu Raunkiaer’s classification Chamaephytes are woody perennials with the resting bud < 0.5 m above the ground. These include small shrubs. Bunchberry (Cornus canadensis) and Vaccinium are chamaephytes. Back to plant growth form menu Back Next Back to vegetative parts main menu Main menu Raunkiaer’s classification Hemicryptophytes are herbaceous perennial plants with the resting bud at or near the soil line. Grasses, clover and dandelion are all hemicryptophytes. Drabra Back to plant growth form menu Back Next Back to vegetative parts main menu Main menu Raunkiaer’s classification Cryptophytes are perennial plants where the resting bud is below ground including those below water. Cryptophytes can be further subdivided into geophytes, helophytes and hydrophytes. Flowering onion Iris Daffodil Back to plant growth form menu Back Next Tulip Hyacinth Back to vegetative parts main menu Main menu Raunkiaer’s classification Cryptophyte Geophytes have roots or shoots that are modified as storage organs. Geophytes include bulbs, corms, rhizomes, tubers, tuberous shoots, and tuberous roots. Rhizome Back to plant growth form menu Tuber Back Next Bulb Corm Tuberous stem Tuberous root Back to vegetative parts main menu Main menu Raunkiaer’s classification Cryptophyte Helophytes are those plants that grow in wet soils. The resting bud is below ground in the wet soil. Marsh marigold (Caltha) Back to plant growth form menu Back Next Cattail (Typha) Back to vegetative parts main menu Main menu Raunkiaer’s classification Cryptophyte Hydrophytes grow in water and resting bud overwinters below the surface of the water often in the lake bed floor. Lotus (Nelumbo nucifera) Back to plant growth form menu Back Next Waterlily (Nymphaea) Back to vegetative parts main menu Main menu Raunkiaer’s classification Therophytes are those plants that survive adverse climatic conditions as seeds. These include all of the annual plants. Back to plant growth form menu Back Next Back to vegetative parts main menu Main menu Raunkiaer’s classification An epiphyte is a plant that grows on another plant, but does not derive water or nutrients from the association. Epiphytic vascular plants occur most often in the moist tropics and include ferns, aroids, orchids, bromeliads, peperomias, and cactus. Non-vascular epiphytes include mosses and lichens. Back to plant growth form menu Back Next Back to vegetative parts main menu Main menu Raunkiaer’s classification Aerophytes are epiphytes, but they have no functional roots and absorb moisture and nutrients through their leaves. A good example of this type of plant is Tillandsia. Tillandsia cyanea) Back to plant growth form menu Back Spanish moss (Tillandsia usneoides) Back to vegetative parts main menu Main menu
© Copyright 2024