angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of br ...

, a hypanthium or floral cup is a structure where basal portions of the

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 ...

, the

corolla Corolla may refer to: *Corolla (botany), the petals of a flower, considered as a unit *Toyota Corolla, an automobile model name * Corolla (headgear), an ancient headdress in the form of a circlet or crown * ''Corolla'' (gastropod), a genus of moll ...

, and the

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

s form a cup-shaped tube. It is sometimes called a floral tube, a term that is also used for

corolla tube Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usuall ...

and

calyx tube A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

. It often contains the nectaries of the

plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...

. It is present in many plant families, although varies in structural dimensions and appearance. This differentiation between the hypanthium in particular species is useful for

identification Identification or identify may refer to: *Identity document, any document used to verify a person's identity Arts, entertainment and media * ''Identify'' (album) by Got7, 2014 * "Identify" (song), by Natalie Imbruglia, 1999 *Identification (a ...

. Some

geometric Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ca ...

forms are

obconic In botany, an obconic is an inverted cone shape. The term is most frequently applied to certain fruit or hypanthium structures with the apical end attached to the stem; however, less frequently the usage may apply to the pistil structure. In the ca ...

shapes as in

toyon ''Heteromeles arbutifolia'' (; more commonly by Californian botanists), commonly known as toyon, is a common Perennial plant, perennial shrub native to extreme southwest Oregon, California, and the Baja California Peninsula. It is the sole speci ...

, whereas some are saucer-shaped as in ''

Mitella caulescens ''Mitella caulescens'', the slightstemmed miterwort, star-shaped mitrewort, leafy miterwort, or creeping miterwort, is an herbaceous perennial flowering plant in the family Saxifragaceae Saxifragaceae is a family of herbaceous perennial flo ...

''. Its presence is diagnostic of many

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

, including the

Rosaceae Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), '' Sorbu ...

Grossulariaceae ''Ribes'' is a genus of about 200 known species of flowering plants, most of them native to the temperate regions of the Northern Hemisphere. The various species are known as currants or gooseberries, and some are cultivated for their edible ...

, and Fabaceae. In some cases, it can be so deep, with such a narrow top, that the flower can appear to have an

inferior Inferior may refer to: * Inferiority complex * An Anatomical terms of location#Superior and inferior, anatomical term of location * Inferior angle of the scapula, in the human skeleton *Inferior (book), ''Inferior'' (book), by Angela Saini * ''The ...

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 ...

- the ovary is below the other attached floral parts. The hypanthium is known by different common names in differing species. In the

eucalypt Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia: ''Eucalyptus'', '' Corymbia'', '' Angophora'', '' Stockwellia'', '' Allo ...

s, it is referred to as the ''gum nut''; in roses it is called the

hip In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint. The hip region ...

Variations in plant species

In myrtles the hypanthium can either surround the ovary loosely or tightly; in some cases it can be fused to the walls of the ovary. It can vary in length. The rims around the outside of the hypanthium contain the calyx lobes or free sepals,

petal Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usuall ...

s and either the stamen or multiple stamen that are attached at one or two points. The flowers of the family Rosaceae, or the

rose A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can b ...

family, always have some type of hypanthium or at least a floral cup from which the sepals, petals and stamens all arise, and which is lined with nectar-producing tissue known as nectaries. The nectar is a sugary substance that attracts

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s and

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

s to the flower, who then take the pollen from the lining of the hypanthium and transfer it to the next flower they visit, usually a neighbouring plant. The stamens borne on the hypanthium are the pollen-producing

reproductive organs A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female ...

of the flower. The hypanthium helps in many ways with the reproduction and

cross pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

pathways of most plants. It provides

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

protection and a medium to sustain the lost pollen, increasing the probability of fertility and cross-pollination. The retained pollen can then attach to pollinators such as

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of ...

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s, bats,

butterflies Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises t ...

and other

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

Wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ...

can act as an instigator for

fertilisation Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...

. The hypanthium is also an adaptive feature for structural support. It helps the

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushr ...

fuse with the flower, in turn strengthening the bond and overall stability and integrity.

References

Bibliography

Books

* * * * *

Websites

External links

* Hypanthium images o
MorphBank
a biological image database {{Botany Plant morphology