Narrow hybrid zone between two subspecies of big sagebrush (Artemisia tridentata: Asteraceae). V. Soil properties

and after flowering. The habitats differed from one another, and there were significant garden by date interactions. The source populations also differed significantly from one another. There were no significant garden by source interactions. Hybrid plants had intermediate respiration rates and did not suffer greater water stress than parental plants. Hybrid plants showed no apparent decrease in adaptation in the important physiological traits respiration and water stress in the hybrid zone. Key words: Artemisia, hybrid zones, respiration, water potential. Résumé: Les auteurs ont examinØ la respiration et le potentiel hydrique de la tige (ψ) chez des plantes parentes et hybrides d