Fig. 1 (a) Outer surface of the rhizosheath on an immature region of a field-grown crown nodal root. The root was excavated, shaken free to loose soil, and observed in a cryo-SEM; (b) a transverse face through a similar root and rhizosheath showing thickness of rhizosheath (R); and (c) a living hair root of the ericaceous species Lysinema ciliatum mounted in water. The 50-µm wide root is surrounded by expanded mucilage, which was produced by cells of tiny root cap. While in soil the mucilage contracted and held soil (arrows) tightly against the root surface. With permission, from the Annual Reviews of Plant Physiology and Molecular Biology, Volume 50, 1999, by Annual Reviews (http://www.AnnualReviews.org) (McCully, 1999)
