Robert Brown suggested two primary divisions - Paniceae and Poaceae, according to the position of the most perfect flower in the spikelet; this is the upper (apparently) terminal one in the first, whilst in the second it occupies the lower position, the more imperfect ones (if any) being above it.
Munro supplemented this by another character easier of verification, and of even greater constancy, in the articulation of the pedicel in the Paniceae immediately below the glumes; whilst in Poaceae this does not occur, but the axis of the spikelet frequently articulates above the pair of empty basal glumes.
Neither of these great divisions will well accommodate certain genera allied to Phalaris, for which Brown proposed tentatively a third group (since named Phalarideae); this, or at least the greater part of it, is placed by Bentham under the Poaceae.
Bamboo comes in many varieties -- there are, in fact one thousand different species of this plant, which is actually a member of the Poaceae, or grass family.