Cover illustration: The inset cover image shows an oblique cut with a razor blade of a fresh, perennial root of the southern rush Lyginia barbata (Restionaceae). The root is approx 3 years old and has an intact sandsheath and persistent root hairs, with a collapsed cortex (brown) and epidermis clearly surrounding the stele. Studies in Lygnia have shown that the structural development of a sandsheath/root hair/epidermis/cortex complex may facilitate water and nutrient uptake while the tissues are alive, and when they die it forms a persistent and essential structure for maintenance of a functional stele. See Shane et al. (pp. 1307-1322).