
An accessory fruit is a
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...
in which some of the flesh is derived not from the floral
ovary
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the bod ...
but from some adjacent tissue exterior to the
carpel
Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...
.
[Esau, K. 1977. ''Anatomy of seed plants''. John Wiley and Sons, New York.] Accessory fruits are usually
indehiscent
Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that o ...
.
Terminology
Alternative terms for accessory fruit are false fruit, spurious fruit, pseudofruit, or pseudocarp. These are older terms for accessory fruit that have been criticized as "inapt",
and are not used by some botanists today.
Examples
The following are examples of accessory fruits listed by the plant organ from which the accessory tissue is derived:
*
Hypanthium
In angiosperms, a hypanthium or floral cup is a structure where basal portions of the calyx, the corolla, and the stamens form a cup-shaped tube. It is sometimes called a floral tube, a term that is also used for corolla tube and calyx tube. It ...
-derived:
pome
In botany, a pome is a type of fruit produced by flowering plants in the subtribe Malinae of the family Rosaceae. Well-known pomes include the apple, pear, and quince.
Etymology
The word ''pome'' entered English in the late 14th century, an ...
s (e.g.
apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ances ...
and
pear
Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the family Rosaceae, bearing the p ...
)
*
Perianth
The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when ca ...
-derived: ''anthocarps'' of the
Nyctaginaceae
Nyctaginaceae, the four o'clock family, is a family of around 33 genera and 290 species of flowering plants, widely distributed in tropical and subtropical regions, with a few representatives in temperate regions. The family has a unique fruit t ...
*
Receptacle
Receptacle may refer to:
Biology
* Receptacle (botany), a plant anatomical part
* Seminal receptacle, a sperm storage site in some insects
Electrical engineering
* Automobile auxiliary power outlet, formerly known as ''cigarette lighter recep ...
-derived:
fig
The fig is the edible fruit of ''Ficus carica'', a species of small tree in the flowering plant family Moraceae. Native to the Mediterranean and western Asia, it has been cultivated since ancient times and is now widely grown throughout the world ...
,
mulberry,
pineapple
The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centurie ...
, and
strawberry
The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely a ...
*
Calyx
Calyx or calyce (plural "calyces"), from the Latin ''calix'' which itself comes from the Ancient Greek ''κάλυξ'' (''kálux'') meaning "husk" or "pod", may refer to:
Biology
* Calyx (anatomy), collective name for several cup-like structures ...
-derived: ''
Gaultheria procumbens
''Gaultheria procumbens'', also called the eastern teaberry, the checkerberry, the boxberry, or the American wintergreen, is a species of ''Gaultheria'' native to northeastern North America from Newfoundland west to southeastern Manitoba, and sou ...
'' and ''
Syzygium jambos
''Syzygium jambos'' is a species of rose apple originating in Southeast Asia and occurring widely elsewhere, having been introduced as an ornamental and fruit tree.Janick, Jules. Paull, Robert E. The Encyclopedia of Fruit & Nuts. Publisher: C ...
''
Fruit with fleshy seeds, such as
pomegranate
The pomegranate (''Punica granatum'') is a fruit-bearing deciduous shrub in the family Lythraceae, subfamily Punicoideae, that grows between tall.
The pomegranate was originally described throughout the Mediterranean Basin, Mediterranean re ...
or
mamoncillo
''Melicoccus bijugatus'' is a fruit-bearing tree in the soapberry family Sapindaceae, native or naturalized across the New World tropics including South and Central America, and parts of the Caribbean. Its stone-bearing fruits are edible. It is ...
, are not considered to be accessory fruits.
Research
Current research has proposed that a single class of genes may be responsible for regulating accessory fruit formation and ripening. A study using strawberries concluded that hormone signaling pathways involving
gibberellic acid
Gibberellic acid (also called gibberellin A3, GA, and GA3) is a hormone found in plants and fungi. Its chemical formula is C19H22O6. When purified, it is a white to pale-yellow solid.
Plants in their normal state produce large amounts of GA3. ...
and
auxin affect gene expression, and contribute to the initiation of accessory fruit development. Metabolic modifications in different developing accessory fruit tissues are due to the varied distributions of compounds such as
triterpenoids
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squale ...
and
steroids
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...
.
See also
*
Aggregate fruit A raspberry_beetle.html" ;"title="raspberry fruit (shown with a raspberry beetle">raspberry fruit (shown with a raspberry beetle larva) is an aggregate fruit, an aggregate of drupelets
image:Aquilegia vulgaris 004.JPG, The fruit of an ''Aquilegia' ...
*
Compound fruit The term compound fruit is not used in technical botanical writing, but is sometimes used when it is not clear which of several fruit types is involved. A compound fruit is "composed of two or more similar parts".
A compound fruit may be:
* An aggr ...
*
Multiple fruit
References
{{Fruits
Fruit morphology