Biomass based porous carbon has been deemed to the most prospective electrode materials for high performance supercapacitors owing to its diversity and reproducibility. Herein, a three-dimensional (3D) porous structure consisting of interconnected carbon nanosheets were synthesized by withered rose through a convenient and efficient carbonization-activation method. This rose-derived active carbon nanosheets (RAC) display a high specific surface area (1911 m(2) g(-1)) and a moderate bulk density (0.55 g cm(-3)). RAC-based supercapacitor electrode exhibits a remarkable cycling stability of 99% capacitance retention after 25000 cycles even at a high specific capacitance of 208 F g(-1). More importantly, its symmetric supercapacitor (SSC) owns an extended voltage window of 2.1 V and an excellent electro-chemical stability (92% capacitance retention after 10000 cycles). (c) 2018 Elsevier Ltd. All rights reserved.