Question

Find the odd pair with regard to the modification of the stem.

Answer 1

Phylloclade are flattened or cylindrical green stems which take over the function of photosyn­thesis in dry habitats. In these plants the leaves are modified into spines to check transpiration. Example : Cactus.

Bulbils are modified floral or vegetative buds with stored food for the plant body. They are meant for vegetative propagation. Bulbils detach to become new plants. Example: Dioscorea, where bulbils are condensed axillary buds, in lily, the floral buds transform to bulbils.

In plants with weak stems, the branches are modified to green thread-like leafless structures known as tendrils. These tendrils provide support and help the plant in climbing.

Vegetative propagation is a type of asexual reproduction that produces progeny by any vegetative propagule. Suckers are one of the units of vegetative propagation. Suckers arise from the basal, underground part of the main stem. It grows horizontally for a distance under the soil and then emerges obliquely upwards. It develops a leafy shoot and adventitious roots before separating from the mother plant. The common sucker-bearing plants are Chrysanthemum, Musa (banana), pineapple etc.

Perennating organs are the organs in plants that help them to survive from one germinating season to another, especially under unfavorable conditions such as drought or winter. Corm is a very fleshy stout modified stem and are organs of perennation.