THE EFFECT OF WATER-STRESS ON THE LIFE-CYCLES OF ERODIUM-CRINITUM CAROLIN AND ERODIUM-CICUTARIUM (L) LHERIT-EX-AITON (GERANIACEAE)

Erodium cicutarium (L.) L'Herit. ex Aiton (Geraniaceae) from temperate Mediterranean Eurasia is naturalized across large areas of arid and s emi-arid Australia to which Erodium crinitum Carolin is native. The re sponse of seed cohorts from Koonamore, SA, of these two species to wat er stress on plant height, leaf numbers, buds and fruit under artifici al drought was investigated to see if there were significant differenc es in their life history strategies which might reflect their evolutio n under different water regimes. Although in E. cicutarium plant size, leaf and bud numbers and fruit/plant biomass ratio were significantly lower under drought, flower and fruit number, fruit size and total ma ss were unaffected. In contrast, E. crinitum was largely unaffected by the drought conditions, showing only an increase in the fruit/plant b iomass ratio.