If you've ever blown the white tufts off a dandelion on a summer day and watched them all float away on the breeze, then you've played a role in the process called seed dispersal. Each of the plant's gossamer white tassels is attached to a single seed and is the vehicle that transports the seed to wherever the wind carries it.
A dandelion flower head is composed of hundreds of individual bright yellow raylike flowers all clustered tightly inside a bract that emerges from a hollow stalk. Growing to a maximum of 18 inches, the stalks contain a bitter milky sap and, along with the sepals at the bottoms of the blossoms, are edible but very bitter-tasting. As the flower head matures, the flower petals wither and are pushed off the plant by the emerging seeds. Each seed develops a white umbrellalike tuft, sometimes called a parachute, that is instrumental in helping the plant to propagate.
The dandelion plant emerges in early spring as a tight rosette of leaves hugging the ground. The small, deeply toothed leaves hug the ground, and it is at this stage that they are harvested and eaten. As the plant's larger upright leaves and blossoms appear, the greens become bitter and usually appeal only to die-hard naturalists who enjoy their flavor. Open dandelion blossoms sometimes close during bad weather or if the temperature drops. Once the seeds, also called achenes, have floated away, the plant withers and the root goes dormant.
The three major forms of seed dispersal are animal, water and wind transportation. Dandelions, like maple trees and milkweed, depend on the wind to carry their embryo-bearing seeds to other areas where they take root and produce new plants. Because these plants depend on the wind, they produce many seeds to assure at least some success with propagation. The dandelion seed's white tuft is capable of carrying it miles from its parent plant, thus assuring survival of the species.
The slightest breeze can carry a dandelion seed high up into the atmosphere by gradually intensifying air currents. From there, it can travel many miles before being deposited on various surfaces. While dandelions thrive in a wide range of soils, they prefer disturbed areas that get plenty of sunlight. Once the seeds containing tiny embryos have successfully taken root, they create plants that are nearly impossible to eradicate. A dandelion's rate of regeneration is high, as it can produce new plants from the smallest bit of tissue left in the ground. Other plants that produce parachute seeds include milkweed, thistle and salsify.
- Wild Man Steve Brill; Common Dandelion
- Maine Organic Farmers and Gardeners Association; Ten Things You Might Not Know About Dandelions; Anita Sanchez
- Gardens Ablaze: Dandelions in Magic & Superstition
- Wayne's Word; Seeds & Fruits Dispersed By Wind; W.P. Armstrong
- Botanical.com; Dandelion; M. Grieve
- University of Maryland Medical Center: Dandelion