It is an erect, waist-high, stout perennial
bunch grass, with grayish to bluish green leaves. Flowering heads are dense, spike-like, and usually long. It is slow to develop from seed, but can form large bunches after several years.
Phalaris arundinacea (reed canary grass) differs from Harding grass in having more distinct rhizomes, and an inflorescence that is compact at first but becomes more open as the branches spread. Hybrids of Harding grass and reed canary grass have been produced. Varieties include 'AQ1', 'Uneta', and 'Australis'.
P. aquatica is a quick-growing grass which incorporates and utilises soil nitrogen rapidly. ==Geography==