Question

Which of the following statements is incorrect related to stem modifications?

• A. Runners are wide, brown, creeping horizontal stems with long internodes.
• B. Offsets are sub-aerial modification seen in the aquatic plants.
• C. Runners arise from an axillary bud present at the base of the stem.
• D. Weak lateral branches arising from the base of the main stem are called stolons.

Answer 1

The correct option is A Runners are wide, brown, creeping horizontal stems with long internodes.

The plant axis that bears shoots, leaves, buds and the roots is called the stem. In some plants, the stem is modified to perform various functions like storage of food, support, vegetative propagation, and protection.

Offsets, runners and stolons are all different types of sub-aerial stems.

Runner is a creeper with long internodes that runs horizontally on the surface of the soil. The nodes have scale leaves, adventitious roots, and axillary buds. Runners arise from the axillary buds. Hence option a is correct.

A large number of runners are produced by a mother runner in all directions. Runners break off and grow into an independent plant. Hence acts as a method of vegetative propagation. Examples include Cynodon (Bermuda grass).

Stolon is a weak lateral stem that arises from the base of the main stem and grows aerially for some time, then bends downwards to touch the ground. Here, the terminal bud gives rise to a new stem and adventitious roots. Examples include Jasmine.

Offset is a short runner with one lone internode. It develops from a leaf axil and then grows as a short horizontal branch and produces a rosette of leaves above and adventitious roots below. It is found in aquatic plants. Examples include Pistia.

Figure : Sub-aerial stem modifications