Type of Heron Whose Collective Name Is a Sedge

This page is the CodyCross answer for the clue below from Botanical Garden, Group 1436, Puzzle 2 (Nuts and Seeds).

Question is: Type of Heron Whose Collective Name Is a Sedge

and the answer is: BITTERN

Word Meaning:

BITTERN — Several bird species in the Botaurinae subfamily of the heron family Ardeidae.

Definitions from Wiktionary.