**Variations in Plant Species:**
– Ovary superior to hypanthium in Spiraea.
– Hypanthium in Rosa.
– Myrtles show variations in hypanthium structure.
– Rosaceae family always has a hypanthium.
– Hypanthium supports nectar-producing tissue attracting pollinators.
**Structural Importance of Hypanthium:**
– Hypanthium supports stamens and nectaries.
– Aids in reproduction and cross-pollination.
– Helps in pollen retention and transfer.
– Acts as an adaptive feature for structural support.
– Strengthens the bond between flower and stem.
**Diagnostic Role of Hypanthium:**
– Presence is diagnostic of various plant families.
– Varies in structural dimensions and appearance.
– Useful for plant identification.
– Can give the appearance of an inferior ovary in some cases.
– Known by different common names in different species.
**References:**
– Foster (2014) – Hypanthium.
– Beentje and Williamson (2010) – The Kew Plant Glossary.
– Hickey and King (2001) – The Cambridge Illustrated Glossary.
– Cronquist (1981).
– Givnish (1997).
**Websites:**
– Foster, Tony – Botany Word of the Day.
– Phytography – Retrieved 27 November 2014.
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.[citation needed] It often contains the nectaries of the plant. 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. Some geometric forms are obconic shapes as in toyon, whereas some are saucer-shaped as in Mitella caulescens.
Its presence is diagnostic of many families, including the Rosaceae, Grossulariaceae, and Fabaceae. In some cases, it can be so deep, with such a narrow top, that the flower can appear to have an inferior ovary - the ovary is below the other attached floral parts. The hypanthium is known by different common names in differing species. In the eucalypts, it is referred to as the gum nut; in roses it is called the hip.