Chemical analyses (ash, protein, lipid, soluble and insoluble carbohydrate) indicated that the rhizome of T. testudinum Banks ex Koenig functions as a storage organ in supporting blade regeneration after defoliation in the field and laboratory, and in seasonal growth. Soluble carbohydrate is the primary reserve mobilized in the rhizome after defoliation and shows the largest decrease in level and amount during the non-growing season. Protein showed no change in the rhizome of clipped or unclipped plants. The short shoot also contributes to blade regrowth as indicated by depletion of protein and soluble carbohydrate after defoliation. The lipid content was low in all organs with no seasonal pattern or effect of defoliation. Protein levels were high in regenerated blades of clipped plants while ash levels were low. Caloric levels were lower in short shoots and rhizomes and in the regenerated blades of clipped plants due to lower levels of organic constituents.