Question

What is a spike of spikelets?

Answer 1

Hint: Inflorescence is the type of pattern of arrangement of flowers with respect to the main axis in a plant. There are broadly two types of inflorescences which are Cymose and Racemose. In the Racemose type of inflorescence, the main axis continues its growth and does not get terminated with the flower.

Complete answer:
A Spike of spikelets is a type of inflorescence. It is a sub-type of racemose inflorescence. Spikelets are seen predominantly in plants belonging to Grass species. The individual flower units constitute spikelets. The unique characteristic of this group is the absence of calyx and corolla. This type of inflorescence is also known as indefinite inflorescence. In this type of inflorescence, the flowers are produced on either side of the main axis. And the type of flower arrangement is known as the acropetal method.

The flowers at the base are produced earlier than the flowers at the top part. In spike inflorescence, the flowers produced are devoid of Pedicel. That is, the flowers are attached directly to the stalk. And the compound form of this spike arrangement is known as the Spike of spikelets. Examples of plants which has this type of inflorescence are Barley and wheat and it comes under the Grass family of Poaceae. Spikelets are the individual flower units and the axis of attachment is known as the Rachis. A number of spikelets together form the spikes.

Note: The other type of inflorescence is cymose inflorescence. In this type, the growth is terminated at the flower part and the flower forms the apex of the shoot. The order in which flowers are arranged is known as the basipetal method.