STUDIES ON WEED SPECIES OF THE GENUS POLYGONUM L.

Summary. Seeds of Polygonum lapathifolium were collected from eight localities during 1962. Plants of these populations were grown in the field and sampled at fortnightly intervals during June and July 1964. There were significant differences between populations in dry weight, leaf area index and nitrogen content at all samplings, and populations also differed in date of flowering and in certain morphological feature. Smooth curves were fitted to some of the growth data, and an account of the fitting procedure is given. For comparison, certain growth functions were calculated from the smooth curves as well as from the observed data. The populations differed in relative growth rate, net assimilation rate, relative nitrogen absorption rate and in certain other calculated functions, A number of growth attributes were significantly correlated with the latitude, longitude or length of the growing season of the locality of origin, and it is tentatively suggested that the populations represent climatic ecotypes.
Études sur des espèces de mauvaises herbes du genre Polygonum L. II. Variations physiologiques dans P. lapathifolium L.