Which one of the following plants produces chasmogamous and cleistogamous flowers?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Commelina
Chasmogamous flowers are open flowers with exposed anthers and stigma, like the flowers of most plants. Cleistogamous flowers never open. Their anthers and stigma lie close together inside the closed flower, so they are always self-pollinated and set seed even when no pollinator is around. A few plants produce both kinds of flowers.
(1) Commelina — Correct. Commelina, like Viola (common pansy) and Oxalis, produces both chasmogamous and cleistogamous flowers.
(2) Vallisneria — Incorrect. Vallisneria is a water-pollinated plant. Its female flowers reach the water surface, and the male flowers or pollen float to them.
(3) Pea — Incorrect. Pea has bisexual flowers that are normally self-pollinated, but it does not produce the two kinds of flowers.
(4) Castor — Incorrect. Castor is monoecious: it has separate male and female flowers on the same plant. It does not produce cleistogamous flowers.
Note: A similar question was also asked in CUET (UG) 2026 on 25-05-2026 (Slot 1).
NCERT Extract:
Pollination – “… Some plants such as Viola (common pansy), Oxalis, and Commelina produce two types of flowers – chasmogamous flowers which are similar to flowers of other species with exposed anthers and stigma, and cleistogamous flowers which do not open at all (Figure 1.9c).”
