Fig. 1

Rhodymenia holmesii Ardissone, 1893: (a–b) habit; (c) thalli with stoloniferous growth giving rise to flattened blades; (d) stipe; (e) transverse section of the blade showing 3–4 layers of medullary cells; (f) transverse section, showing layers and arrangement of cortical cells; (g) surface view of the cortical cells from the apex; (h) cortical cells from the median part and subcortical cells (arrows) in surface view; (i) cortical cells from the stipe in surface view. Scale bars: a–b, 3 cm; c–d, 1 cm; e, 30 μm; f, 100 μm; g, 20 μm; h–i, 30 μm