Which one of the following plants produces both the chasmogamous and cleistogamous flowers?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Commelina
A plant that bears two kinds of flowers has chasmogamous flowers, which open and expose their anthers and stigma, and cleistogamous flowers, which never open. Cleistogamous flowers set seed even when no pollinator is present.
(1) Vallisneria — Incorrect. This is a water-pollinated plant. It is not known for two kinds of flowers.
(2) Commelina — Correct. Commelina, along with Viola and Oxalis, produces both chasmogamous and cleistogamous flowers.
(3) Zostera — Incorrect. This is a sea grass pollinated under water. It is not known for two kinds of flowers.
(4) Hydrilla — Incorrect. This is a water-pollinated plant. It is not known for two kinds of flowers.
Note: A similar question was also asked in CUET (UG) 2026 on 07-06-2026 (Slot 2).
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).”
