Accessory fruit

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A selection of accessory fruits (from left to right: pear, fig, and strawberry) Pseudocarps (2943643065).jpg
A selection of accessory fruits (from left to right: pear, fig, and strawberry)

An accessory fruit is a fruit that contains tissue derived from plant parts other than the ovary. In other words, the flesh of the fruit develops not from the floral ovary, but from some adjacent tissue exterior to the carpel (for example, from receptacles or sepal). As a general rule, the accessory fruit is a combination of several floral organs, including the ovary. In contrast, true fruit forms exclusively from the ovary of the flower. [1]

Contents

Accessory fruits are usually indehiscent, meaning that they do not split open to release seeds when they have reached maturity. [2]

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", [1] and are not used by some botanists today.[ citation needed ]

Incorporated organs

The following are examples of accessory fruits listed by the plant organ from which the accessory tissue is derived: [3]

Accessory Fruit Organs
OrganFruit
Hypanthium apple, pear, rose hip
Involucre pineapple
Peduncle cashew apple
Perianth anthocarps of the Nyctaginaceae
Receptacle fig, mulberry, pineapple, strawberry
Calyx eastern teaberry, rose apple

Fruit with fleshy seeds, such as pomegranate or mamoncillo, are not considered to be accessory fruits. [4]

Examples

Apples and pears

Apple section, showing seeds plus papery expression of the ovary, surrounded by tissue formed from ripening of the hypanthium Apple red delicius cross-cut.jpg
Apple section, showing seeds plus papery expression of the ovary, surrounded by tissue formed from ripening of the hypanthium

The part of apples and pears that is consumed is, in fact, the hypanthium. The ovary is the papery core that surrounds the apple seeds. As the hypanthium ripens it forms the edible tissues. [5]

Roses

For roses, the hypanthium is the tissue that composes the edible part of rosehips. Roses and apples are both members of the Rosaceae family; the fact that they have similar fruit morphology is a major consideration in placing them in the same taxonomic family. [5]

Strawberries

On this strawberry, the many pips located on the surface have germinated. The pips of the strawberry are its true fruit. Nombreux akenes de fraise situes en surface ayant germe sur la fraise elle meme.jpg
On this strawberry, the many pips located on the surface have germinated. The pips of the strawberry are its true fruit.

The edible part of the strawberry is formed, as part of the ripening process, from the receptacle of the strawberry flower. The true fruits (hence, containing the seeds) are the roughly 200 pips (which are, technically, achenes, a true fruit that contains a single seed from a single ovary). These pips dot the exterior of the strawberry. [6]

Cashew apple

The cashew 'apple' and its attached drupe, which contains the edible seed Cashew apples.jpg
The cashew ‘apple’ and its attached drupe, which contains the edible seed

The cashew apple is an oval- or pear-shaped structure that develops from the pedicel and the receptacle of the cashew flower and is technically called a hypocarpium. [7] [8] [9] It ripens into a yellow or red structure about 5–11 cm (2–4+14 in) long. [10] [8] The true fruit of the cashew tree is a kidney–shaped drupe that grows at the end of the cashew apple; the seed inside this drupe is the cashew nut of commerce. [10]

Pineapple

Pineapple in flower Ananas comosus-pineapple flowers - kaitcckk.jpg
Pineapple in flower

The pineapple is formed when 50 to 200 unpollinated flowers coalesce in a spiral arrangement— the flowers form individually and then fuse as a single 'multiple fruit'. The ovaries develop into berries and the fruit forms around an intercalary spike. The intercalary inflorescence (cluster of flowers) results when the terminal cluster of flowers are left behind by the growth of the main axis of the plant. Each polygonal area on the pineapple's surface is an individual flower. [11]

Research

Current research has proposed that a single class of genes may be responsible for regulating accessory fruit formation and ripening. [12] A study using strawberries concluded that hormone signaling pathways involving gibberellic acid and auxin affect gene expression, and contribute to the initiation of accessory fruit development. [6] Metabolic modifications in different developing accessory fruit tissues are due to the varied distributions of compounds such as triterpenoids and steroids. [13]

See also

Related Research Articles

<span class="mw-page-title-main">Fruit</span> Seed-bearing part of a flowering plant

In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.

<span class="mw-page-title-main">Berry</span> In the culinary sense, small edible fruit

A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples of berries in the culinary sense are strawberries, raspberries, blueberries, blackberries, red currants, white currants and blackcurrants. In Britain, soft fruit is a horticultural term for such fruits.

<span class="mw-page-title-main">Drupe</span> Fleshy fruit with hard inner layer (endocarp or stone) surrounding the seed

In botany, a drupe is an indehiscent type of fruit in which an outer fleshy part surrounds a single shell of hardened endocarp with a seed (kernel) inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries.

<span class="mw-page-title-main">Cashew</span> Species of flowering plant in the family Anacardiaceae

The cashew tree is a tropical evergreen tree native to South America in the genus Anacardium that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as 14 metres, but the dwarf cultivars, growing up to 6 m (20 ft), prove more profitable, with earlier maturity and greater yields. The cashew seed is commonly considered a snack nut eaten on its own, used in recipes, or processed into cashew cheese or cashew butter. Like the tree, the nut is often simply called a cashew. Cashew allergies are triggered by the proteins found in tree nuts, and cooking often does not remove or change these proteins.

<span class="mw-page-title-main">Fruit tree</span> Tree which bears fruit

A fruit tree is a tree which bears fruit that is consumed or used by animals and humans — all trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, the term "fruit tree" is limited to those that provide fruit for human food. Types of fruits are described and defined elsewhere, but would include "fruit" in a culinary sense, as well as some nut-bearing trees, such as walnuts.

<span class="mw-page-title-main">Achene</span> Class of simple non-opening dry fruits

An achene, also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent. Achenes contain a single seed that nearly fills the pericarp, but does not adhere to it. In many species, what is called the "seed" is an achene, a fruit containing the seed. The seed-like appearance is owed to the hardening of the fruit wall (pericarp), which encloses the solitary seed so closely as to seem like a seed coat.

<span class="mw-page-title-main">Pome</span> Fruit with apple-like features

In botany, a pome is a type of fruit produced by flowering plants in the subtribe Malinae of the family Rosaceae. Pome fruits consist of a central "core" containing multiple small seeds, which is enveloped by a tough membrane and surrounded by an edible layer of flesh. Pome fruit trees are deciduous, and undergo a dormant winter period that requires cold temperatures to break dormancy in spring. Well-known pomes include the apple, pear, and quince.

<span class="mw-page-title-main">Ripening</span> Process in fruits that causes them to become more palatable

Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green, and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make the fruit seem tarter. This effect is attributed to the Brix-Acid Ratio. Climacteric fruits ripen after harvesting and so some fruits for market are picked green.

<span class="mw-page-title-main">Syconium</span> Technical name for a type of plant fruit

Syconium is the type of inflorescence borne by figs, formed by an enlarged, fleshy, hollow receptacle with multiple ovaries on the inside surface. In essence, it is really a fleshy stem with a number of flowers, so it is considered both a multiple and accessory fruit.

<span class="mw-page-title-main">Gynoecium</span> Female organs of a flower

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 pistils and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium. The gynoecium is often referred to as the "female" portion of the flower, although rather than directly producing female gametes, the gynoecium produces megaspores, each of which develops into a female gametophyte which then produces egg cells.

<span class="mw-page-title-main">Strawberry</span> Edible fruit

The garden strawberry 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 appreciated for its characteristic aroma, bright red color, juicy texture, and sweetness. It is consumed in large quantities, either fresh or in such prepared foods as jam, juice, pies, ice cream, milkshakes, and chocolates. Artificial strawberry flavorings and aromas are also widely used in products such as candy, soap, lip gloss, perfume, and many others.

<span class="mw-page-title-main">Aggregate fruit</span> Category of fruit

An aggregate fruit or etaerio is a fruit that develops from the merger of several ovaries that were separated in a single flower. In contrast, a simple fruit develops from one ovary, and a multiple fruit develops from multiple flowers. In languages other than English, the meanings of "aggregate" and "multiple" fruit are reversed, so that "aggregate" fruits merge several flowers. The differences in meaning are due to a reversal in the terminology by John Lindley, which has been followed by most English-language authors.

<span class="mw-page-title-main">Ovary (botany)</span> Flowering plant reproductive part

In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule(s) and is located above or below or at the point of connection with the base of the petals and sepals. The pistil may be made up of one carpel or of several fused carpels, and therefore the ovary can contain part of one carpel or parts of several fused carpels. Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary, and, for each individual pollen grain, to fertilize one individual ovule. Some wind pollinated flowers have much reduced and modified ovaries.

<span class="mw-page-title-main">Berry (botany)</span> Botanical fruit with fleshy pericarp, containing one or many seeds

In botany, a berry is a fleshy fruit without a stone (pit) produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants (aubergines) and bananas, but exclude certain fruits that meet the culinary definition of berries, such as strawberries and raspberries. The berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a potentially edible "pericarp". Berries may be formed from one or more carpels from the same flower. The seeds are usually embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as Capsicum species, with air rather than pulp around their seeds.

<span class="mw-page-title-main">Fruit (plant structure)</span> Internal makeup of fruits

Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits.

Generally, fleshy fruits can be divided into two groups based on the presence or absence of a respiratory increase at the onset of ripening. This respiratory increase—which is preceded, or accompanied, by a rise in ethylene—is called a climacteric, and there are marked differences in the development of climacteric and non-climacteric fruits. Climacteric fruit can be either monocots or dicots and the ripening of these fruits can still be achieved even if the fruit has been harvested at the end of their growth period. Non-climacteric fruits ripen without ethylene and respiration bursts, the ripening process is slower, and for the most part they will not be able to ripen if the fruit is not attached to the parent plant. Examples of climacteric fruits include apples, bananas, melons, apricots, tomatoes, as well as most stone fruits. Non-climacteric fruits on the other hand include citrus fruits, grapes, and strawberries Essentially, a key difference between climacteric and non-climacteric fruits is that climacteric fruits continue to ripen following their harvest, whereas non-climacteric fruits do not. The accumulation of starch over the early stages of climacteric fruit development may be a key issue, as starch can be converted to sugars after harvest.

<span class="mw-page-title-main">Simple fruit</span>

Simple fruits are the result of the ripening-to-fruit of a simple or compound ovary in a single flower with a single pistil. In contrast, a single flower with numerous pistils typically produces an aggregate fruit; and the merging of several flowers, or a 'multiple' of flowers, results in a 'multiple' fruit. A simple fruit is further classified as either dry or fleshy.

Anacardium othonianum is a tree native from the tropical savanna (cerrado) region of Brazil, whose fruit is similar to that of the common cashew tree of the Brazilian Northeast. It is locally known by the Tupi-derived name cajuí, and by the Portuguese names caju-de-árvore-do-cerrado, caju-vermelho-de-goiás, cajuzinho-do-cerrado or just cajuzinho.

<span class="mw-page-title-main">Ethylene (plant hormone)</span> Alkene gas naturally regulating the plant growth

Ethylene (CH
2
=CH
2
) is an unsaturated hydrocarbon gas (alkene) acting as a naturally occurring plant hormone. It is the simplest alkene gas and is the first gas known to act as hormone. It acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, the abscission (or shedding) of leaves and, in aquatic and semi-aquatic species, promoting the 'escape' from submergence by means of rapid elongation of stems or leaves. This escape response is particularly important in rice farming. Commercial fruit-ripening rooms use "catalytic generators" to make ethylene gas from a liquid supply of ethanol. Typically, a gassing level of 500 to 2,000 ppm is used, for 24 to 48 hours. Care must be taken to control carbon dioxide levels in ripening rooms when gassing, as high temperature ripening (20 °C; 68 °F) has been seen to produce CO2 levels of 10% in 24 hours.

References

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  2. "Glossary Details – The William & Lynda Steere Herbarium". sweetgum.nybg.org. Retrieved 2021-03-17.
  3. Merriam Webster Collegiate Dictionary entries for syconium, accessory fruit, core, and strawberry, Merriam-Webster, Inc., 2006
  4. Holland, D.; Hatib, K.; Bar-Ya'akov, I. (2009), "Pomegranate: Botany, Horticulture, Breeding", Horticultural Reviews, John Wiley & Sons, Ltd, pp. 127–191, doi:10.1002/9780470593776.ch2, ISBN   978-0-470-59377-6 , retrieved 2021-11-28
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  6. 1 2 Zhou, Junhui; Sittmann, John; Guo, Lei; Xiao, Yuwei; Huang, Xiaolong; Pulapaka, Anuhya; Liu, Zhongchi (March 2021). "Gibberellin and auxin signaling genes RGA1 and ARF8 repress accessory fruit initiation in diploid strawberry". Plant Physiology. 185 (3): 1059–1075. doi:10.1093/plphys/kiaa087. PMC   8133647 . PMID   33793929.
  7. Varghese, T.; Pundir, Y. (1964). "Anatomy of the pseudocarp in Anacardium occidentale L.". Proceedings of the Indian Academy of Sciences, Section B. 59 (5): 252–258. doi:10.1007/BF03052341. S2CID   83230755.
  8. 1 2 James A Duke (1983). "Anacardium occidentale L." Handbook of Energy Crops. (unpublished); In: NewCROP, New Crop Resource Online Program, Center for New Crops and Plant Products, Purdue University. Retrieved 10 December 2019.
  9. "Cashew". Encyclopedia Britannica. 7 April 2020. Retrieved 8 May 2021.
  10. 1 2 Morton, Julia F. (1987). Cashew apple, Anacardium occidentale L. Center for New Crops and Plant Products, Department of Horticulture and Landscape Architecture, Purdue University, W. Lafayette, IN. pp. 239–240. ISBN   978-0-9610184-1-2. Archived from the original on 15 March 2007. Retrieved 18 March 2007.{{cite book}}: |work= ignored (help)
  11. "Plant Details - Information about Ananas comosus Plant". www.efloraofgandhinagar.in. Retrieved 2023-03-18.
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  13. Dashbaldan, Soyol; Rogowska, Agata; Pączkowski, Cezary; Szakiel, Anna (25 August 2021). "Distribution of Triterpenoids and Steroids in Developing Rugosa Rose (Rosarugosa Thunb.) Accessory Fruit". Molecules. 26 (17): 5158. doi: 10.3390/molecules26175158 . PMC   8433923 . PMID   34500591.