Achene

An achene (/əˈkiːn/;[1] Greek ἀ, a, privative + χαίνειν, chainein, to gape;[2] 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 (formed from one carpel) and indehiscent (they do not open at maturity). 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.[2]

Strawberry surface close up macro
Strawberry surface, showing achenes
Strawberry surface super close up macro achene
Two achenes on the surface of a strawberry

Examples

Cypsela Cynara
Cypsela of Cynara

The fruits of buttercup, buckwheat, caraway, quinoa, amaranth and cannabis are typical achenes.

The achenes of the strawberry are sometimes mistaken for seeds. The strawberry is an aggregate fruit with an aggregate of achenes, and what is eaten is accessory tissue.

Flower morphology - longitudinal section showing achene formation and hypanthium in Rosa-01
Rosa hypanthium encircling separate achene fruits

A rose produces an aggregate of achene fruits that are encompassed within an expanded hypanthium[3] (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, such 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 utricle is like an achene, but the fruit is bladder-like or inflated.[4]

Fruits of sedges are sometimes considered achenes although their one-locule ovary is a compound ovary.

The fruit of the family Asteraceae is also so similar to an achene that it is often considered to be one, although it derives from a compound inferior ovary (with one locule). A special term for the Asteraceae fruit is cypsela (plural cypselae or cypselas). For example, the white-gray husks of a sunflower "seed" are the walls of the cypsela fruit. Many cypselas (e.g. dandelion) have calyx tissue attached that functions in biological dispersal of the seed.

References

  1. ^ "achene". Oxford English Dictionary third edition. Oxford University Press. September 2009. Retrieved 30 July 2018.
  2. ^ a b Wikisource-logo.svg Gilman, D. C.; Peck, H. T.; Colby, F. M., eds. (1905). "Achene" . New International Encyclopedia (1st ed.). New York: Dodd, Mead.
  3. ^ "Hypanthium", Wikipedia, 2018-08-31, retrieved 2019-01-24
  4. ^ Harris, James G. (2001). Plant Identification Terminology: An Illustrated Glossary (2nd ed.). Payson, Utah: Spring Lake Publishing. p. 131. ISBN 0-9640221-6-8.

Gallery

Make a Wish by Vefobitseq

Cypselae on a dandelion "clock" (the matured capitulum) can disperse in the wind due to the hair-like calyx tissue above each ovary.

Dandelion Microscopic 1

A microscopic view of a dandelion "clock" showing the receptacle and the cypselas.

Acer buergerianum seeds

Samaras of Acer buergerianum are achenes with large wing-like structures.

Pulsatilla alpina fruit

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 cultivar Uptick Cream and Red 12

Coreopsis tinctoria showing 4 stages of inflorescence, there are two reddish-brown achenes

Coreopsis tinctoria cultivar Uptick Cream and Red 13-achenes

Coreopsis tinctoria showing achene forming as flower dies

External links

Agoseris apargioides

Agoseris apargioides is a species in the sunflower family, is commonly called seaside agoseris or seaside false-dandelion. It is native to the Pacific coast of the United States from Washington to central California, where it grows primarily on coastal dunes.Agoseris apargioides is a low-growing, perennial herb with milky or orange sap, that may be stemless or with long, rhizome-like stems that are buried by drifting sand. The leaves form low rosettes on the ground. They are slender to broad, up to 15 centimeters long, and usually with 3-5 pairs of lobes along the margins (these sometimes lacking). The peduncle of the inflorescence can be as tall as 45 centimeters but is usually much shorter. The flower head is up to 2 centimeters wide, surrounded by glabrous to hairy phyllaries, and contains yellow ray florets (the outer ones often have a purple strip on the lower surface) but no disc florets. The fruit is an achene between 5-12 millimeters long; the lower part of the achene contains a single seed, while the upper portion of the achene forms a slender beak that possesses a terminal, white pappus.

Bougainvillea

Bougainvillea ( or ) is a genus of thorny ornamental vines, bushes, or trees. The inflorescence consists of large colourful sepallike bracts which surround three simple waxy flowers. It is native to South America from Brazil west to Peru and south to southern Argentina. Different authors accept between four and 18 species in the genus. Bougainvillea are also known as buganvilla (Spain), bugambilia (Mexico, Guatemala, Cuba, Philippines), bouganvilla (India), pokok bunga kertas (Indonesia, Malaysia), bougenville (Pakistan), Napoleón (Honduras), jahanamiya (Arab World), veranera (Colombia, Nicaragua, El Salvador, Costa Rica and Panama), trinitaria (Colombia, Panama, Puerto Rico, Dominican Republic & Venezuela), Santa Rita (Argentina, Bolivia, Paraguay and Uruguay), papelillo (Northern Peru), primavera (Brazil), Drillingsblume (triplet flower, Germany), vukamvilia (Greece) or Saron / Saron Par / Sarawn (in Mizoram, India).

The vine species grow anywhere from 1 to 12 m (3 to 40 ft.) tall, scrambling over other plants with their spiky thorns. The thorns are tipped with a black, waxy substance. They are evergreen where rainfall occurs all year, or deciduous if there is a dry season. The leaves are alternate, simple ovate-acuminate, 4–13 cm long and 2–6 cm broad. The actual flower of the plant is small and generally white, but each cluster of three flowers is surrounded by three or six bracts with the bright colours associated with the plant, including pink, magenta, purple, red, orange, white, or yellow. Bougainvillea glabra is sometimes referred to as "paper flower" because the bracts are thin and papery. The fruit is a narrow five-lobed achene.

Bougainvillea are relatively pest-free plants, but they may be susceptible to worms, snails and aphids. The larvae of some Lepidoptera species also use them as food plants, for example the giant leopard moth (Hypercompe scribonia).

Caryopsis

In botany, a caryopsis (plural caryopses) is a type of simple dry fruit—one that is monocarpellate (formed from a single carpel) and indehiscent (not opening at maturity) and resembles an achene, except that in a caryopsis the pericarp is fused with the thin seed coat.

The caryopsis is popularly called a grain and is the fruit typical of the family Poaceae (or Gramineae), which includes wheat, rice, and corn.The term grain is also used in a more general sense as synonymous with cereal (as in "cereal grains", which include some non-Poaceae). Considering that the fruit wall and the seed are intimately fused into a single unit, and the caryopsis or grain is a dry fruit, little concern is given to technically separating the terms fruit and seed in these plant structures. In many grains, the "hulls" to be separated before processing are flower bracts.

Ciney

Ciney (French pronunciation: ​[si.nɛ]; Walloon: Cînè) is a Walloon city and municipality located in the Belgian province of Namur. On January 1, 2006, Ciney had a total population of 14,958. The total area is 147.56 km² which gives a population density of 101 inhabitants per km².

The municipality consists of the following sub-municipalities: Achêne, Braibant, Chevetogne, Ciney, Conneux, Leignon, Pessoux, Serinchamps, and Sovet, along with a number of villages, including Chapois.

Several beers from the city are now brewed by Alken-Maes and still bear the name: Ciney Blonde, Ciney Brown, and Ciney Special. Those beers were first brewed in 1978.

The city was damaged by a heavy storm on 14 July 2010. The bell tower, the city's symbol and also Ciney's beer symbol, collapsed on its nave. No injuries were reported. Reconstruction took more than a year and cost some million euros.

Dryadoideae

The Dryadoideae subfamily of the Rosaceae consists of four genera, all of which share root nodules that host the nitrogen-fixing bacterium Frankia. They are subshrubs, shrubs, or small trees with a base chromosome number of 9, whose fruits are either an achene or an aggregate of achenes.

Filipendula

Filipendula is a genus of 12 species of perennial herbaceous flowering plants in the family Rosaceae, native to the temperate regions of the Northern Hemisphere. Well-known species include meadowsweet (Filipendula ulmaria) and dropwort (Filipendula vulgaris), both native to Europe, and queen-of-the-forest (Filipendula occidentalis) and queen-of-the-prairie (Filipendula rubra), native to North America.

The species grow to between 0.5–2 m tall, with large inflorescences of small five-petalled flowers, creamy-white to pink-tinged in most species, dark pink in F. rubra. Filipendula fruit are unusual, sometimes described as an indehiscent follicle, or as an achene.Filipendula species are used as food plants by the larvae of some Lepidoptera species: emperor moth, grey pug, grizzled skipper, Hebrew character, lime-speck pug, mottled beauty and the satellite have all been recorded on meadowsweet.

The species were in the past sometimes treated in a broad view of the genus Spiraea, but genetic research has shown that they are less closely related than previously considered.

The genus name Filipendula derives from the Latin words filum "thread" and pendulus "hanging", referring to the tubers of F. vulgaris, which are attached to one other by thread-like roots.

Follicle (fruit)

In botany, a follicle is a dry unilocular fruit formed from one carpel, containing two or more seeds. It is usually defined as dehiscing by a suture in order to release seeds, for example in Consolida (some of the larkspurs), peony and milkweed (Asclepias).

Some difficult cases exist however, so that the term indehiscent follicle is sometimes used, for example with the genus Filipendula, which has indehiscent fruits that could be considered intermediate between a (dehiscent) follicle and an (indehiscent) achene.An aggregate fruit that consists of follicles may be called a follicetum. Examples include hellebore, aconite, Delphinium, Aquilegia or the family Crassulaceae, where several follicles occur in a whorl on a shortened receptacle, or Magnolia, which has many follicles arranged in a spiral on an elongated receptacle.The follicles of some species dehisce by the ventral suture (as in Banksia), or by the dorsal suture (as in Magnolia).

Hieracium greenei

Hieracium greenei (not to be confused with Hieracium greenii) is a species of hawkweed known by the common name Greene's hawkweed.

Hieracium greenei is native to the forests of the Klamath Mountains and neighboring ranges in southern Oregon and northern California.Hieracium greenei is a small hawkweed forming a basal rosette of densely hairy gray-green leaves, each 5 to 10 centimeters (2-4 inches) long and some with toothed edges. It bolts a thin, hairy stem which reaches 20 to 40 centimeters (8-16 inches) tall. The stem bears an inflorescence of several flower heads containing yellow ray flowers but no disc flowers. The fruit is a ribbed achene about half a centimeter (0.2 inches) long with a light brown pappus.

Leontodon taraxacoides

Leontodon taraxacoides is a species of hawkbit known by the common name lesser hawkbit, rough hawkbit, or hairy hawkbit. It is native to Europe and North Africa but it can be found in many other places across the globe as an introduced species and often a noxious weed. This is a dandelion-like herb growing patches of many erect, leafless stems from a basal rosette of leaves. The leaves are 2 to 15 centimeters long, 0.5 to 2.5 centimeters wide, entire or lobed, and green in color. Atop the stems are solitary flower heads which are ligulate, containing layered rings of ray florets with no disc florets. The florets are yellow with toothed tips. The fruit is a cylindrical achene with a pappus of scales. Fruits near the center of the flower head are rough, while those growing along the edges of the head are smooth.

Parietaria

Parietaria is a genus of flowering plants in the family Urticaceae, native to temperate and tropical regions across the world.They are annual or perennial herbaceous plants growing to 20–80 cm tall, with green or pink stems. The leaves are alternate, simple, entire, often with a cluster of small leaves in their axils. Individual flowers are bisexual or unisexual, produced in clusters of three to many together in the leaf axils. Plants have either bisexual flowers or both staminate ("male") and carpellate ("female") flowers. The fruit is a small dry achene.

Pilea

Pilea, with 600–715 species, is the largest genus of flowering plants in the nettle family Urticaceae, and one of the larger genera in the Urticales.

It is distributed throughout the tropics, subtropics, and warm temperate regions (with the exception of Australia and New Zealand).

The majority of species are succulent shade-loving herbs or shrubs, which are easily distinguished from other Urticaceae by the combination of opposite leaves (with rare exceptions) with a single ligulate intrapetiolar stipule in each leaf axil and cymose or paniculate inflorescences (again with rare exceptions).

Pilea is of little economic importance; six species have horticultural value (P. cadierei, P. grandifolia, P. involucrata, P. microphylla, P. nummulariifolia, and P. peperomioides), and one species is used in Chinese traditional medicine (P. plataniflora). The genus has attracted little monographic attention since Weddell (1869), and the majority of taxonomic contributions have come from floristic treatments. To date, 787 species names have been published (International Plant Names Index, 2003) and estimates for the species number range from 250 to 1000. Based on previous floristic treatments, about 30% of the species from regions not yet covered by contemporary floristic treatments may be undescribed.

The genus name is derived from Latin pileus, "felt cap", because of the calyx covering the achene.[1]

Ranunculus cymbalaria

Ranunculus cymbalaria is a species of buttercup known by the common names alkali buttercup and seaside buttercup. It is native to much of Eurasia and parts of North and South America, where it grows in many types of habitat, especially in moist to wet areas such as marshes, bogs, and moist spring meadows. It is a perennial herb producing several stems a few centimeters to nearly 40 centimeters long. Some are prostrate against the ground and are stolons which root in moist substrate, and some are erect. The leaves are variable in shape, the basal ones with notched or slightly divided leaf blades borne on long petioles, and any upper leaves much reduced in size. The inflorescence bears one or more flowers on erect stalks. The flower has five to eight pale yellow petals, each under a centimeter long. The protruding receptacle at the center of the flower becomes a cylindrical cluster of fruits, each of which is an achene.

Ranunculus lobbii

Ranunculus lobbii is a species of buttercup known by the common name Lobb's buttercup, or Lobb's aquatic buttercup. It is native to a few areas in western North America, where it is reported from British Columbia, Oregon, and northern California. It is an aquatic plant, growing in various types of shallow-water habitat, including forest ponds and vernal pools. It is an annual herb producing submerged stems 20 to 80 centimeters long which may float at the surface. The blades of the leaves are tiny and divided into threadlike segments. If any leaves develop on stem parts which are exposed to air they are much different in morphology, developing larger, more robust leaves. Flowers have generally 5 petals which are white in color and about half a centimeter long. Many stamens and pistils fill the center of the flower. The fruit is an achene borne in a spherical cluster.

Ranunculus uncinatus

Ranunculus uncinatus is a species of buttercup known by the common names woodland buttercup and little buttercup. It is native to western North America from Alaska to California to New Mexico, where it grows in wet, wooded habitat such as forest streambanks. It is a perennial herb producing a slender, erect stem which may exceed half a meter in maximum height. The lightly hairy lower leaves have blades deeply divided into three toothed lobes borne on long petioles. The upper leaves are smaller and divided into narrower lobes. The flower has four or five yellow petals a few millimeters long around a central receptacle and many stamens and pistils. The fruit is an achene borne in a spherical cluster.

Rhynchospora alba

Rhynchospora alba, the white beak-sedge, is a plant in the sedge family, Cyperaceae. It is a tufted herbaceous perennial around 50 cm tall, with white inflorescences that flower in August. The fruit of the sedge is a small achene with a characteristic beak-like cap. It is dispersed by wind or falls by gravity, leading to individuals existing in tight clumps. The species favours wet, acidic and nutrient poor soils, thriving in Sphagnum-dominated bogs, but also peaty grasslands. As such it is often used as a positive indicator for bog and mire ecosystem health.The species was first described by Linnaeus in 1753 under a different genus and name, Schoenus albus, but was subsequently reclassified into the novel genus Rhynchospora by Vahl in 1805. It has a wide range across the Northern Hemisphere, extending from the inland wetlands of North America, across Europe to the Korean Peninsula. Due to this large range, there is considerable variation between populations, and numerous varieties have been identified. The plant has few uses, though it is used as an ornamental in the UK.

Samara (fruit)

A samara (, UK also: ) is a winged achene, a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent (not opening along a seam). The shape of a samara enables the wind to carry the seed farther away than regular seeds from the parent tree, and is thus a form of anemochory.

In some cases the seed is in the centre of the wing, as in the elms (genus Ulmus), the hoptree (Ptelea trifoliata), and the bushwillows (genus Combretum).

In other cases the seed is on one side, with the wing extending to the other side, making the seed autorotate as it falls, as in the maples (genus Acer) and ash trees (genus Fraxinus).A samara is sometimes called a key and is often referred to as a wingnut, helicopter or whirlybird, whirligig, polynose, or, in the north of England, a spinning jenny. During the autumn months, they are a popular source of amusement for children who enjoy tossing them in the air and watching them spin to the ground.

Some species that normally produce paired samaras, such as Acer pseudoplatanus, also produce them in groups of 3 or 4.

Schoenus nigricans

Schoenus nigricans is a species of sedge known by the common names black bog-rush and black sedge. It is native to Eurasia, parts of Africa, Australia, and southern North America, including Mexico and the southernmost United States. It grows in many types of wetlands and other moist and alkaline habitat, including marshes, springs, seeps, peat bogs, heath, and alkali flats. This perennial plant grows in low, tight clumps 20 to 70 centimeters tall, with threadlike leaves bearing wide, dark brown ligules. The inflorescence is a small, flattened cluster of dark spikelets. The fruit is an achene coated in a hard, white shell.

Strawberry

The garden strawberry (or simply strawberry; Fragaria × ananassa) is a widely grown hybrid species of the genus Fragaria, collectively known as the strawberries. It is cultivated worldwide for its 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 preserves, juice, pies, ice creams, milkshakes, and chocolates. Artificial strawberry flavorings and aromas are also widely used in many products like lip gloss, candy, hand sanitizers, perfume, and many others.

The garden strawberry was first bred in Brittany, France, in the 1750s via a cross of Fragaria virginiana from eastern North America and Fragaria chiloensis, which was brought from Chile by Amédée-François Frézier in 1714. Cultivars of Fragaria × ananassa have replaced, in commercial production, the woodland strawberry (Fragaria vesca), which was the first strawberry species cultivated in the early 17th century.The strawberry is not, from a botanical point of view, a berry. Technically, it is an aggregate accessory fruit, meaning that the fleshy part is derived not from the plant's ovaries but from the receptacle that holds the ovaries. Each apparent "seed" (achene) on the outside of the fruit is actually one of the ovaries of the flower, with a seed inside it.In 2016, world production of strawberries was 9.2 million tonnes, led by China with 41% of the total.

Wyethia angustifolia

Wyethia angustifolia is a species of flowering plant in the aster family known by the common names California compassplant and narrowleaf mule's ears. It is native to the west coast of the United States from Washington to California, where it grows in grassland, meadows, and other open habitat. It is a perennial herb growing from a tough taproot and caudex unit and producing a stem 30 to 90 centimeters tall. The leaves have lance-shaped blades up to 50 centimeters tall. The inflorescence produces one or more large sunflower-like flower heads at the top of the hairy stem. The head has narrow, hairy phyllaries at the base. It contains up to 21 yellow ray florets each up to 4.5 centimeters long and many yellow disc florets. The fruit is an achene which may be nearly 2 centimeters long including its pappus.

Types of fruits
Types of fruits
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