Q.Pollen grains are fused together as a single mass called as:

Pollinium is the term for pollen grains of an anther that are fused into a single waxy mass, seen typically in Orchidaceae and Asclepiadaceae.

In most flowering plants, individual pollen grains separate from each other after they are shed from the anther. However, in a few families, the pollen grains of each anther lobe remain stuck together as one coherent mass called a pollinium (plural: pollinia). This adaptation helps ensure that a whole mass of pollen, rather than single grains, is transferred to the stigma in one visit of a pollinator, greatly improving pollination efficiency.

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"Diadelphous" describes how stamens are fused by their filaments — it is a term used to classify the androecium (the male whorl of a flower).

When describing the androecium, botanists classify flowers by how the stamens' filaments are fused to one another:

• Monadelphous — all filaments fused into a single bundle/tube around the ovary (e.g., China rose, Hibiscus).
• Diadelphous — filaments fused into two bundles. The classic example is the pea flower (family Fabaceae), where 9 stamens are fused into one bundle and 1 stamen (the posterior one) remains free, giving a "9+1" arrangement. …