AN ANALYSIS OF THE INFLUENCE OF CLONE SIZE AND STOLON CONNECTIONS BETWEEN RAMETS ON THE GROWTH OF GLECHOMA HEDERACEA L.

Two experiments were conducted in which the influence of size of clones and the persistence of stolon connections on subsequent development were examined in Glechoma hederacea. In the first experiment, clones were grown from either one unrooted ramet or from either one, two or three connected, rooted ramets, for 8 weeks, in either nutrient-rich or nutrient-poor sand. The survival, number of ramets and dry weight of the clones produced were dependent on the number of established ramets at the start of the experiment. Clones in nutrient-rich sand developed a greater number of ramets, stolon branches, total length of stolon, mean leaf area per ramet and total leaf area per clone than clones of corresponding initial size in nutrient-poor sand. In the second experiment, the stolon connections between ramets of G. hederacea clones growing in boxes were either left intact or severed soon after each ramet had rooted. After 10 weeks of growth, the total dry weight of the intact clones and the mean dry weight of their ramets were significantly greater than the corresponding values for severed clones. The spatial distribution of ramets showed marked differences between the treatments. Severed clones produced a greater number of rooted ramets within the boxes and a smaller number of unrooted ramets beyond the box edges than intact clones. Density of ramets more than doubled when stolons were severed. Maintenance of stolon connections in G. hederacea is advantageous because it improves the probability of daughter ramet survival, promotes rapid lateral expansion of the clone and reduces inter-ramet competition through the production of fewer, larger ramets.