In this case, all the flowers are developed only on one side of the inflorescence axis, as in Begonia etc. Helicoid cyme: When the lateral branches are developed successively on the same side of the main axis of a monochasial cyme, forming a sort of helix, it is called helicoid cyme. It is of two types – helicoid and scorpioid. Monochasial or uniparous cyme: When the main axis terminates in a flower and then give rise to a single lateral branch ending in a flower, the inflorescence is said to be a monochasial cyme. In some cases, however, more than two lateral branches may develop from the base of the terminal flowers, and in that case, the inflorescence is called polychasial cyme. Accordingly, they are called monochasial cyme or dichasial cyme. In cymose inflorescence, usually one lateral branch or two lateral branches may develop at a time from the main axis and also from the successive axis. Thus, in a cymose inflorescence, the terminal flower is older and opens earlier than the lateral ones. Lateral branches develop from the main axis just below the terminal flower.Įach of these branches also terminates with a flower, and from the base of these terminal flowers, lateral branches may develop in the same manner. In cymose inflorescence, the growth of the main axis is checked by the development of a terminal flower. Examples, Tridax, marigold, sunflower etc. The central florets are tubular, mostly bisexual and are called disc-florets. They are strap shaped and when unisexual are called ray-florets. The outer florets in the head are older than the inner ones. At the basal region of these florets, one or more walls of bracts are developed and form an involucre. The main axis is elongated and becomes pendulous, example, mulberry etc.Ĭapitulum or head: Here, the main axis of the inflorescence is flattened and a number of small sessile flowers are developed on it. When the fleshy axis becomes branched and each branch bears a spadix being covered by a bract it is called a compound spadix as in date palm, coconut etc.Ĭatkin: This is a drooping spike, which bears unisexual sessile flowers. The whole inflorescence is covered with a large fleshy bract known as spathe, which attracts the insect, example, colocasia, musa etc. The female flowers are usually developed at the basal region of the axis, while the male flowers are found towards the upper parts. Spadix: This is also a spike with a fleshy axis where unisexual sessile flowers are developed. Thus the flower is enclosed by lemma and palea, example, rice, wheat etc. Opposite to the lemma, there is a small bracteole, called the palea. At the axil of the lemma, a flower is developed. The main axis develops small branches bearing the sessile flowers.Įach spikelet has two small empty glumes at its base and just above them, a flowering glume, called the lemma. Each spikelet comprises of one or few flowers called the florets. Spikelet: This is a reduced type of spike and is very small. Spike: In this case, the main axis is elongated and the flowers are borne in acropetal succession, example, Achyranthes, Adhatoda etc. Raceme inflorescence with sessile flowers: Such an umbel is called compound umbel, example, coriander, cumin etc. More commonly, lateral branches are developed from the main axis of the umbel and each branch bears the flowers arranged in the form of an umbel. Such an umbel is commonly referred as simple umbel, example, wild coriander etc. These bracts together form an involucre at the bases of the flowers. A whorl of bract is always associated with the umbel and each flower is developed from the axil of the bract. The pedicels of all the flowers are more or less of the same length. Umbel: Here, the main axis is shortened and the flowers develop in the group from the same level of the axis, so that they appear to have spreaded from a common point.