The Eucalypt Lignotuber: a Position-dependent Organ

Observational and experimental evidence is presented to show that the capacity to form a lignotuber is not restricted to the cotyledonary, and a few succeeding, nodes on the primary seedling stems of certain eucalypts, but is also a property of shoots arising from their accessory buds. Erect secondary shoots from the lignotuber, may bear lignotubers at a few nodes, rhizostolons at many nodes along their length, and, like stolons, rhizomes may give rise to leafy shoots bearing basal lignotubers. These facts describe a so-called position effect for the production of lignotubers, in the sense that the term has been used for other position-dependent phenomena in plants. Seedlings of lignotuberous species remain competent to form lignotubers over a long period of adversity during which lignotubers are not formed. Shoots of non-lignotuberous species do not inhibit lignotuber development when grafted to lignotuberous species.