Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by

Wind pollinated flowers usually have single ovule in the ovary, as in grasses, and the non-attractive flowers are packed into inflorescence. 

(1) Bee-pollinated plants have several ovules in the ovary and, usually, the flowers are larger and colourful or
packed into attractive inflorescences.

(3) Bat-pollinated flowers are usually larger, have several ovules and may be present singly or packed as larger
inflorescences. They offer nectar to bats as reward. 

(4) Water-pollinated flowers may also have single ovule in the ovary but the flowers are usually not packed into
inflorescence, e.g., Vallisneria.