Panicum virgatum--Switchgrass is a popular prairie grass known for its lush foliage and conical seedheads that turn a golden brown in fall.  Its stiff stems stand up over winter better than all the other grasses. At home on almost any soil, it will grow three to six feet tall in your driest sand and most horrendous clay. Also grows luxuriantly on good soils. This fast-spreading plant produces purple flower spikes.  The foliage turns yellow in the autumn.