The aim of study was to determine ligno-cellulose quality and calorific value of cup plant Silphium perfoliatum L., whereas impact of nutrition, years and sites on the quality were evaluated as main effects within a huge pilot field experiment. Two complete data sets of acid-detergent fiber (ADF), acid-detergent lignin (ADL), crude cellulose (CE), hemicellulose (HEM), neutral-detergent fiber (NDF) and high heating value (HHV) were evaluated, a primary one in terms of quality content and a secondary one in terms of quality yield. Average, minimal and maximal ADF content was