achenes

An achene is a type of simple dry fruit that contains a single seed. The fruit wall, or pericarp, remains dry and does not split open at maturity (it is indehiscent). In an achene, the seed is typically attached to the inner surface of the pericarp at a single point by the funiculus, and the seed coat remains distinct from the fruit wall.

Most achenes occur in the Asteraceae (the sunflower family), where many species produce numerous small, light fruits that are easily dispersed by wind or animals. Common examples include sunflower seeds, dandelion seeds, and buckwheat seeds. In strawberries, the small yellow achenes on the surface are true fruits, each containing a single seed, while the red flesh is an enlarged receptacle.

Achenes vary in size and form; many have adaptations for dispersal, such as a fluffy pappus in dandelions or a beak-like extension in some species that helps seed release. Because they are usually dry and light, achenes are well suited to rapid dispersal and colonization in open habitats.

Taxonomically, recognizing achenes helps distinguish fruit types in plant classification, especially within Asteraceae. They are also a common subject in studies of fruit morphology and seed dispersal strategies.