SOME RELATIONSHIPS BETWEEN XEROPHYTISM AND THE CONTENT OF RESIN, NORDIHYDROGUAIARETIC ACID AND PROTEIN OF LARREA DIVARICATA CAV

摘要: Larrea divaricata is the dominant plant growing over more than 30,000,000 acres of hottest and driest intermountain plains Mexican southwestern American deserts. It a remarkable plant, for although it considered to be typical xerophyte all deserts these regions, appears similar mesophytes in morphology. RUNYON (11) has described properties which adapt leaves drought conditions as being added an organization considerable degree mesomorphic. Various hypotheses have been advanced explain resistance creosote bush but none appear adequate. Many investigators credited cuticular resins with function reducing transpiration (6, 14, 16, 19, 20) ASHBY (2), SPALDING (15) SCHRATZ (13) found rate unexpectedly high even bushes having sticky resin. Ashby no evidence clogging very numerous mesomorphic stomata. The fairly extensive root system was partly responsible its by some early workers (5, 20). This explanation doubtful since rather those other species angiosperms grown under semiarid DITTMER (7). MALLERY (10) reported that osmotic value cell sap small twigs especially conditions. However, BOON-LONG (3) shown pressures do not reduce evaporation greatly. (11, 12) observed extreme drought, mature die immature buds dry out turn brown. When favorable moisture exist again, continue growth. According Runyon, only seed known whose ability ceasing development before maturity, surviving intense periods resuming During desiccation, continues at low diurnal variations content occur. Runyon could find any significant morphological difference between leaves. He structurally plants,