From Wikipedia, the free encyclopedia
The
acorn
is the
nut
of the
oak
tree and its close relatives, in the family
Fagaceae
. Acorns usually contain a
seedling
surrounded by two
cotyledons
(seedling leaves), enclosed in a tough
shell
known as the pericarp, and borne in a cup-shaped
cupule
. This acorn of the species
Quercus robur
(the pedunculate oak), with a length of 25 millimetres (1 inch), was photographed in
Keila
, Estonia.
Photograph credit:
Ivar Leidus
See also
[
edit
]