NATURE OF THE PLANT COMMUNITY. VI. TEXAS GRASSLAND COMMUNITIES UNDER TRANSPLANTED CONDITIONS

Abstract

McMillan, Calvin. (U. Texas, Austin.) Nature of the plant community. VI. Texas grassland communities under transplanted conditions. Amer. Jour. Bot. 48(9): 778–785. Illus. 1961.—Clones of 7 grass taxa, Bouteloua gracilis (H. B. K.) Lag., B. eriopoda (Torr.) Torr., B. curtipendula (Michx.) Torr., Panicum virgatum L., the Andropogon scoparius Michx. complex, the Andropogon gerardi Vitman‐hallii Hack. complex, and Sorghastrum nutans (L.) Nash, were transplanted from throughout their distribution in Texas and studied in an experimental garden at Austin. Restricted to western Texas and Panhandle areas, Bouteloua gracilis and B. eriopoda contained similar early‐flowering clones throughout their distribution. Less restricted to western sites, B. curtipendula contained later‐flowering types from eastern and central areas. In the 4 remaining, widespread taxa, early‐flowering potential characterized clones from western sites. These 4 widespread taxa contain the latest‐flowering clones from the coast of southern Texas. Clones of Stipa leucotricha Trin. and Rupr. from a broad area in Texas lacked a flowering gradient. Grassland communities of western Texas and the Panhandle, attuned to short growing seasons and low rainfall, were composed of opportunists, the Bouteloua species, and early‐flowering variants within the widespread species. Communities of central Texas in habitats of highly unpredictable moisture pattern and a relatively long growing season contained later‐flowering variants. Coastal communities attuned to a long growing season contained the latest‐flowering variants.