Systematics of Gramineae: A Cluster Analysis Study

Summary Cluster analysis techniques were applied to 215 grass genera using 85 morphological and microscopic characters. Clustering was run on 1) gross morphological characters, 2) microscopic characters and 3) on combination of the two. Neither the morphological nor the microscopic characters alone resulted in an appreciable grouping of the genera. The microscopic characters, however, produced clusters that better approach the present subfamilial classifications. Combination of the two subsets of characters resulted in eight clusters representing the modern subfamilies Pooideae, Oryzoideae, Panicoideae, Eragrostoideae, Arundinoideae, Centostecoideae, Bambusoideae and a new potential subfamily (Nardoideae) that included Lygeum, Nardus and Diarrhena. The tribal constituents of these subfamilies are discussed in detail. It has been concluded that classification of grasses seems more natural at the level of the subfamily than tribe.