Grass, sedge or rush?

How to tell if your plant is a grass, sedge or rush. Timecodes 0:00 - Introduction 0:15 - A useful rhyme 0:27 - Sedges have edges 0:50 - Rushes are round 0:58 - Grasses are hollow right down to the ground 1:04 - How many directions do the leaves grow in? 1:24 - 2 directions in grasses 1:51 - 3 directions in sedges 2:21 - Many directions in rushes 2:28 - Differences in the flowering parts of the plants 2:49 - How many scales beneath each flower? 3:21 - 2 scales beneath a grass flower 3:53 - 1 scale beneath a sedge flower 4:25 - 6 scales beneath a rush flower 4:48 - Diagrams of grass, sedge and rush flowers