Fig. 15.

Picture of a piece of a root of Typha latifolia L. (Typhaceae), an herbaceous wetland monocot. This root illustrates the potential root order dimorphism and its consequences for measurements of morphological traits. The pictured root, grown in water, has a total length of 6.33 m, out of which 0.11 m (1.7%) is taken by the thick basal root. Average diameter of the fine lateral roots is 0.21 mm, that of the basal root is 1.66 mm. Average diameter of the whole sample is 0.23 mm. Specific root length of the basal root, lateral roots and total sample are 6 m g⁻¹, 230 m g⁻¹ and 138 m g⁻¹, respectively. The porous basal root with a root tissue density (dry mass per fresh root volume; RTD) of 0.08 g cm⁻³ takes up 53% of the sample volume, while the less porous lateral roots with a RTD of 0.125 g cm⁻³ take up 47% of the volume, resulting in an average RTD of 0.10 g cm⁻³.