What Adaptations Do Plants Have to Disperse Seeds? Plants rely on their environment to disperse seeds. • Wind • Animal Transport External Internal Other: burying seeds • Drop to ground Wind Dispersal Some structures allow seeds to be easily carried in the wind. Achene Pappus Some plants depend upon animals to disperse their seeds. There are three variations of animal dispersal: •External Transport Examples of seed structures for external transport: •Hooks •Barbs •Internal Transport •Seeds are encased in fleshy fruits •Inadvertent dispersal (burying seeds) Projections extending from a seed case attach onto a passing animal, carrying the seed to a new location. Barbs attach to animal fur. Barb Fleshy fruits surround seeds to be consumed and expelled by animals. The Oak tree depends upon the squirrel for its seed dispersal. Squirrels bury acorns in the Fall and often forget where they are in the winter. These seeds then sprout new trees. Some plants simply drop the seeds on the ground. Individual seed What are some disadvantages of this method? What adaptations do seeds have to assist in dispersal? Identify the adaptation and type of dispersal for each of the following pictures. 1 2 3 4 5 Answers 1 3 Acorn: Food; animal dispersal Composite: Pappus; wind 2 4 Wildflower: Drop dispersal Wildflower: Hooks; animal dispersal Composite: Pappus; wind 5 This is an individual seed case from the burdock bur taken at 60X. Seed photos in this presentation were taken with the QX3 Intel Play Microscope.