Polysaccharide gums were separated from Lesquerella fendleri seed. Fracturing the seed and air classification yielded, 34% by weight, fractions enriched in gums. Water-swollen epidermal seed cells, after fracturing in a Waring Blendor and filtering, yielded a fraction that is 21% of the seed. Crude gums from hexane-extracted meal ranged from 35 to 47% depending on the amount of centrifugal force used to remove seed residue. Viscosity enhancement was greatest for the gums isolated from the fractured epidermal cells and for a gel fraction separated by a two-step process. A typical gum has a Rha:Ara:Xyl:Man:Gal:Glc molar ratio of 0.5:1.0:0.1:0.1:1.4:0.5 and contains 15% galacturonosyl residues, 14% protein, and 7% ash that is mainly Ca and Mg, which may serve as cross-linking cations for the uronic acid residues