Hypanthodium

In different plants, the way the flowers are arranged is different. This arrangement of flowers on the floral axis of a plant is referred to as inflorescence. There are three main types of inflorescence:

Racemose: Indeterminate or Indefinite

Cymose – determinate or definite

Mixed

Hypanthodium is a special type of cymose inflorescence.

Special types of cymose inflorescence Image

Cymose Inflorescence

Cymose Inflorescence

The cymose inflorescence is when the apical growth of the floral axis ends with the formation of a flower. This inflorescence is also referred to as determinate or definite inflorescence. Here, the terminal flowers are the oldest while the young flowers can be seen on the lower side, and this is a basipetal arrangement. The rachis in this type of inflorescence is terminated by a flower bud at a very early stage, and the following buds gradually develop towards the lower side of the axis.

Cymose inflorescence can be one of the following four types:

Hibiscus rosa-sinensis of the Malvaceae family is an example of a solitary plant.

Monochasial Cyme (also known as a Uniparous Cyme or Monochasium) is an example found in the flowering plant Hamelia patens of the Rubiaceae family.

Dichasial Cyme, also known as Biparous Cyme or Dichasium, is an example of a flowering pattern seen in plants such as Nyctanthus arbor-tristis of the Oleaceae family.

Multiparous Cyme, Polychasial Cyme, Polychasium, or Pleiochasium (e.g. Calotropis procera of Asclepiadaceae)

Apart from these, there are special types of cymose inflorescence, such as:

Leonurus sibiricus of the Lamiaceae family is an example of a Verticillaster.

Poinsettia pulcherrima is an example of a cyathium.

Hypanthodium (e.g. Ficus cunia and Banyan)

Coenanthium: Example - Pick-aback plant, Dorstenia cordifolia of Moraceae

What is Hypanthodium Inflorescence?

The receptacle in this type of inflorescence takes on a spherical shape, resembling a hollow-sphere (syconium) with an interior cavity. This is created through the merging of the three cymes in close proximity to one another. These spherical receptacles are akin to a closed, fleshy vessel with a small opening at the peak, which opens to the outside through this opening.

Three types of unisexual flowers arranged on the inner surface of the receptacle in cymose groups are male, sterile female, and fertile female flowers. These flowers are small and sessile.

Hypanthodium Flowers

These fleshy receptacles, shaped like a flask, have narrow canals with a terminal pore located at one end. The pore may be surrounded by scales, and the canal is lined with hair pointing downwards. The interior of the receptacles contain male flowers near the pore, and female flowers near the base.

The neutral, sterile, or gall flowers can occur between the two groups, forming an inflorescence of these three types of flower-bearing axes.

Hypanthodium Inflorescence Example - Hypanthodium Example

Examples of Hypanthodium Inflorescence

The Hypanthodium inflorescence is a special type of cymose inflorescence found in the genus Ficus of the family Moraceae, such as Banyan (Ficus bengalensis), Peepal (Ficus religiosa), and Fig (Ficus carica).

Cyathium

A cyathium is a special type of inflorescence in which the bracts unite to form a cup-shaped structure. On the margin or periphery of this cup, a few secretory glands are formed. Inside the cup, the female flowers are surrounded by a large number of male flowers, which are themselves surrounded by bracts.

A scorpioid cyme is a type of specialized cymose inflorescence which appears as a single flower. The axis is suppressed, forming a convex receptacle. The centre of the receptacle exhibits a long-stalked and naked female flower having a tricarpellary gynoecium. This is surrounded by a vast number of male flowers.

The male flowers consist of a single stamen attached to a short stalk, known as the pedicel, which develops in the axil of a hairy bracteole. The entire inflorescence is enveloped by a cup-shaped green involucre, which is composed of fused bracts. The involucre may have one or two nectar glands on its outer walls, or may have no gland at all. Flowers grow in a centrifugal pattern, with the inner side facing outward.

Poinsettia pulcherrima and some members of Euphorbiaceae have a type of cyathium inflorescence.

Difference between Cyathium and Hypanthodium

  • A cyathium is a type of inflorescence found in the Euphorbiaceae family, which consists of a single, cuplike involucre containing several flowers.

  • A hypanthodium is a type of inflorescence found in the Rosaceae family, which consists of a cup-shaped receptacle that bears several flowers.

Cyathium

The cupular structure appears to be formed by an involucre of bracts. At the centre, there is a single female flower, surrounded by several stalked male flowers, each with a single stamen. This type of inflorescence is commonly seen in Euphorbia.

Hypanthodium

The cupular receptacle of Ficus contains an apical opening at the apex. Within this cavity, both male and female flowers are found on the interior walls, which are enclosed by the cupular structure. This type of inflorescence is characteristic of Ficus.

Back To Study Material

NEET Study Material (Biology)

Reach to us