Stomate Density in Relation to Winter Hardiness of Ilex opaca Ait.1

Abstract

Stomate density was determined for 11 cultivars of Ilex opaca which had been subjectively ranked for winter hardiness as either very hardy, hardy, semi-hardy, or not hardy on the basis of field observations recorded over a 5-year period. Variance analysis revealed that the number of stomates for the cultivars rated very hardy was significantly lower than that of the cultivars rated not hardy. Stomate counts for the cultivars in the intermediate hardiness classes all fell within the range delimited by the counts of the very hardy and not hardy cultivars.