Premise: Cynosurus cristatus, Crested dog's-tail, is a short-lived perennial grass in the family Poaceae, characterised by a seed head that is flat on one side. It typically grows in species rich grassland. It thrives in a variety of soil types but avoids the acid and calcareous extremes of pH, and prefers well drained soils. It may be grown as an ornamental plant.
Hypothesis: Crested dog's-tail can only grow in species rich grassland.