This study was carried out to determine the chemical composition, in situ dry matter (DM) degradability, in vitro digestibilities and metabolizable energy (ME) contents of Prangos uechtritzii at different stages of maturity (prebud, mid-flower and late flower) naturally grown in some arid regions of Turkey. The proportion of leaf at mid- and late-flower decreased compared to prebud stage. Stage of maturity affected DM and crude protein contents of the P. uechtritzii and fractions. In the whole-plant, NDF and ADF concentrations increased with plant maturity as a result of increased stem ratio. The effective degradability of dry matter, in vitro dry matter digestibility, in vitro organic matter digestibility, and ME did not change greatly by stage of maturity. Compared to ordinary forages used in ruminant feeding, the forage nutritive value of P. uechtritzii was equal to or better. © 2003 Elsevier Science Ltd. All rights reserved.