Question

Keel is the characteristic feature of the flower of:
A. Aloe
B. Tomato
C. Tulip
D. Indigofera

Answer 1

Hint: When two anterior small petals are fused at the base they form a keel. When the keel is formed it forms a concave shape. The keel is seen in the family of Papilionaceae.

Complete answer:
> Option A: Aloe’s flowers generally appear in spikes, tubular, yellowish-orange, and heights at 3 feet tall. A cluster of flowers is arranged on a long stalk. So it does not have any keel. So aloe is the wrong option.

> Option B: In a tomato plant the flower parts dry up and fall (petals, stamens, stigma) when the tomato fruit develops. Tomatoes are developed from the ovary. Therefore, they also do not possess keel. So, this option is wrong.

> Option C: Tulip flowers are the perfect flowers with approximately 3000 varieties of flowering plants. In tulip flowers, the male (6 stamens) and female (pistil) parts are perfectly separated and there is no fusion of parts in the flower and do not form any keel. So, this option is wrong.

> Option D: Keel is formed by edge-edge attachment of the petals at the base and they form a keel.

Hence, the correct answer is option (D).

Additional information:
The Fabaceae or Leguminosae is commonly known as the legume, pea, or bean family, is a large and economically vital family of flowering plants. It has trees, shrubs, and perennial or annual herbaceous plants, which are easily recognized by their fruit and their compound, stipulated leaves.

Note: The flowers of family Papilionaceae have butterfly-shaped corolla, the outermost petal is called standard or vexillum, two lateral petals are similar and clawed, they are called wings or alae and the two anterior petals are called a keel. This type of petal arrangement is found in the bean, gram, pea, Indigofera, etc.