Question

Inflorescence having a unisexual sessile flower is?
(a) Spike
(b) Spikelet
(c) Catkin
(d) Spadix

Answer 1

Hint: The enlarge cluster of single-sex flowers bearing scaly bracts and generally lacking petals. It is a kind of smaller or string-like inflorescence portrayed by a single moderately stout axis on which unisexual sessile or subsessile apetalous blossoms are bunched in a spiral or whorled pattern.

Complete answer:
1. Spike, in which peduncle has bisexual and sessile flowers. It is a type of racemose inflorescence. Example: achyranthes.

2. Spikelet is a small and special spike. Flowers are produced in the axil of fertile bracts called a lemma. It is a type of racemose inflorescence. Example: wheat.
3. Catkin is a kind of racemose inflorescence. It can contain a pendulous spike in the leaf pivot that bears sessile and unisexual blossoms. For example, oak.
4. The spadix is a spike with a fleshy axis and has both male and female flowers. It is encircled by enormous shaded bracts called the spathe. It is a kind of racemose inflorescence. Such as palm.

Additional information: Female catkin from an assortment of black mulberry (Morus nigra). Mulberry blossoms are delivered in a catkin, with male and female catkins on various trees. Male blossoms have four stamens while female blossoms consist of a solitary pistil firmly encompassed by four unnoticeable sepals. Every carpel or pistil (additionally alluded to as a gynoecium) comprises a forked stigma, a short style, and a spherical ovary. During multiple fruits, each ovary (carpel) becomes a drupelet, and it also ripens the cluster of drupelets (syncarp). Seedless, parthenocarpic fruits might be the formation of pollination by male trees.
So the correct answer is ‘Catkin’.

Note: At the base of each filament is a fleshy green sepal. Male trees are called "fruitless mulberry" since they do not produce messy fruits that stain clothing and walkways. Male trees produce extensive pollen which can raise havoc with hay-fever sufferers because mulberries are wind-pollinated.