Aggregated Cones in Pinus Halepensis

Aggregated female cones were found in 192 Pinus halepensis trees growing in 54 populations in Israel, in habitats of vastly differing ecological conditions. All of these trees also carried normal (1-5 in a whorl) female cones. The number of aggregates per tree varied from one to several dozen. Some of the trees formed aggregates every year, after the first year of aggregate formation, while others formed aggregates only once, or at long intervals. Not all cones in the aggregates reached maturity. The number of cones in an aggregate ranged from six to 62, and they were usually smaller than normal. Many of the trees with aggregates showed other abnormalities, e.g., individual female cone scales, proliferated dwarf shoots, three-needled dwarf shoots, shorter cone stalks, needles on cone stalks, larger terminal cones on the main axis in cones formed during the current year, proliferated female cones, and degradation of the main axis above the aggregate. The clusters probably result from replacement of dwarf shoots by ovulate cones.