What is "lignotuber"

n. (context botany English) A starchy enlargement (caudex), usually of a root, of a woody plant, serving to store water.

A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. The crown contains buds from which new stems may sprout, as well as stores of starch that can support a period of growth in the absence of photosynthesis.

Plants possessing lignotubers include Eucalyptus marginata (Jarrah), most mallees, and many Banksia species. Lignotubers develop from the cotyledonary bud in seedlings of several oak species including cork oak Quercus suber, but do not develop in several other oak species, and are not apparent in mature cork oak trees.

Many plants with lignotubers grow in a shrubby habit, but with multiple stems arising from the lignotuber. The term lignotuberous shrub is used to describe this habit.