southeast Asia; many of these species probably originated in China. From the proposed dispersal history of ancestral taxa, it seems that although orange [ Citrus sinensis (L.) Osbeck.], lemon [ Citrus limon (L.) Burm. f.], mandarin ( Citrus reticulata
). Stimulated respiration rates have also been observed in lemon ( Citrus limon Burm.), lettuce ( Lactuca sativa L.), eggplant ( Solanum melongena L.), cucumber ( Cucumis sativus L.), and potato ( Solanum tuberosum L.) exposed to CO 2 -enriched environments