| Abstract: | The density of Aralia spinosa prickles varied with the age and architectural position of annual increments. Prickles were most common on young (1–4 years old, 2–3 m tall), unbranched stems. Prickles were less common on branches and were absent on inflorescences. Ramets that grew as sprouts after injury had more and longer prickles than ramets that had not arisen in this way. Leaf prickles were also more common on the leaves of trunk annual increments than on the leaves of branch annual increments. As with stem prickles, leaf prickles were more common on the leaves of stems that had sprouted after cutting than on the leaves of ramets that had not been previously cut. As bark developed, stem prickles were lost at a rate of about 10% per year. While dense prickles characterized young individuals, older individuals (>15 years old) had very few prickles. |
