Figure 5
Yiduxylon trilobum gen. et sp. nov. from Hubeiv. (a-b) Successive transverse sections of a stem bearing a petiole base. Stem with three-ribbed primary xylem, secondary xylem and cortex. Sparganum-type outer cortex in (a). (b) Petiole base with vascular bundles, ground tissue and sparganum-type outer cortex. Arrow indicating part enlarged in (e). Slides 4–1 and 4–6. (c-d) Enlargement of (a) and (b), respectively. (e) Enlargement of (b, arrow) showing two vascular bundles in oblique longitudinal view. (f) Enlargement of lower left part of (b) showing two vascular bundles in oblique transverse view. Arrows indicating protoxylem strands. Scale bars = 1 mm (c), 0.2 mm (e), 0.5 mm (f).