Achene
An achene (
Examples
The fruits of
are typical achenes.The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an accessory fruit with an aggregate of achenes on its outer surface, and what is eaten is accessory tissue.
A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium (aka floral tube), which is a structure where basal portions of the calyx, the corolla, and the stamens unite with the receptacle to form a cup-shaped tube.
Variations
A winged achene, as in maple, is called a samara.
Some achenes have accessory hair-like structures that cause them to tumble in the wind in a manner similar to a tumbleweed. This type sometimes is called a tumble fruit or diaspore. An example is Anemone virginiana.
A caryopsis or grain is a type of fruit that closely resembles an achene, but differs in that the pericarp is fused to the thin seed coat in the grain.
An
Fruits of
The fruit of the family
Gallery
-
Cypselae on a dandelion "clock" (the maturedcalyxtissue above each ovary. -
A microscopic view of a dandelion "clock" showing the receptacle and the cypselas. -
Samaras of Acer buergerianum are achenes with large wing-like structures. -
The diaspore of Pulsatilla (family Ranunculaceae) disperses in the wind, either as single achenes or as the entire aggregate of achenes. The achenes have long hairy appendages that developed from the style of the flower. -
Coreopsis tinctoria showing 4 stages of inflorescence, with two reddish-brown flower heads containing cypselas -
Coreopsis tinctoria flower head containing cypselas forming asfloretsfinish blooming
References
- ^ "achene". Oxford English Dictionary (Online ed.). Oxford University Press. Retrieved 30 July 2018. (Subscription or participating institution membership required.)
- ^ New International Encyclopedia(1st ed.). New York: Dodd, Mead.
- Kahle/Austin Foundation.
External links
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