In botany, a drupe is an indehiscent fruit in which an outer fleshy part surrounds a
shell of hardened endocarp with a seed inside.
These fruits usually develop from a single carpel, and mostly from flowers with superior
ovaries.
The definitive characteristic of a drupe is that the hard, lignified stone is derived
from the ovary wall of the flower.
In an aggregate fruit composed of small, individual drupes, each individual is termed a drupelet.
Other fleshy fruits may have a stony enclosure that comes from the seed coat surrounding
the seed, but such fruits are not drupes.
Some flowering plants that produce drupes are coffee, jujube, mango, olive, most palms,
pistachio, white sapote, and all members of the genus Prunus, including the almond, apricot,
cherry, damson, nectarine, peach, and plum.
Terminology The term stone fruit can be a synonym for
drupe or, more typically, it can mean just the fruit of the Prunus genus.
Freestone refers to a drupe having a stone which can be removed from the flesh with ease.
The flesh is not attached to the stone and does not need to be cut to free the stone.
Freestone varieties of fruits are preferred for uses that require careful removal of the
stone, especially if removal will be done by hand.
Freestone plums are preferred for making homegrown prunes, and freestone sour cherries are preferred
for making pies and cherry soup.
Clingstone refers to a drupe having a stone which cannot easily be removed from the flesh.
The flesh is attached strongly to the stone and must be cut to free the stone.
Clingstone varieties of fruits in the genus Prunus are preferred as table fruit and for
jams, because the flesh of clingstone fruits tends to be more tender and juicy throughout.
Tryma is a specialized term for such nut-like drupes that are difficult to categorize.
Hickory nuts and walnuts in the Juglandaceae family grow within an outer husk; these fruits
are technically drupes or drupaceous nuts, and thus not true botanical nuts.
Ecology Many drupes, with their sweet, fleshy outer
layer, attract the attention of animals as a food, and the plant population benefits
from the resulting dispersal of its seeds.
The endocarp is sometimes dropped after the fleshy part is eaten, but is often swallowed,
passing through the digestive tract, and returned to the soil in feces with the seed inside
unharmed.
This passage through the digestive tract can reduce the thickness of the endocarp, and
thus can aid in germination rates.
The process is known as scarification.
Examples Typical drupes include olives, peaches, plums,
and cherries.
The coconut is also a drupe, but the mesocarp is fibrous or dry, so this type of fruit is
classified as a simple dry fruit, fibrous drupe.
Unlike other drupes, the coconut seed is unlikely to be dispersed by being swallowed by fauna,
due to its large size.
It can, however, float extremely long distances across oceans.
Bramble fruits are aggregates of drupelets.
The fruit of blackberries and raspberries comes from a single flower whose pistil is
made up of a number of free carpels.
However, mulberries, which closely resemble blackberries, are not aggregate fruit, but
are multiple fruits, actually derived from bunches of catkins, each drupelet thus belonging
to a different flower.
Certain drupes occur in large clusters, as in the case of palm species, where a sizable
array of drupes are found in a cluster.
Examples of such large drupe clusters include Jubaea chilensis in central Chile and Washingtonia
filifera in the Sonoran Desert of North America.
Gallery
See also Polypyrenous drupe
References
External links Identification Of Major Fruit Types
Fruits Called Nuts "Drupe".
New International Encyclopedia.
1905.