CLONAL GROWTH AND FRAGMENT REGENERATION OF RUMEX-OBTUSIFOLIUS L

Clonal growth and fragment regeneration of Rumex obtusifolius L. were analysed in two different studies. Clonal growth system was described by a morphological study of underground structure of different-aged in dividuals, using maximal branching order in the stem system as an age estimator. Glasshouse experiments were conducted, testing the regenera tive capacity of different below-ground parts and the establishment of above root-collar fragments planted at different depths under contras ting water regimes. Results showed the presence of a 'phalanx' type cl onal growth system in grassland populations of Rumex. The main structu re involved in clonal growth proved to be the stem system; the region above the root collar was also the only part able to regrow after dama ge. Stem fragment regeneration occurred to depths of 15 cm, but was pr evented in soils maintained at waterlogging and field capacity. The si gnificance of these results in relation to nonchemical control of Rume x populations in grasslands is discussed. (C) 1995 European Weed Resea rch Society