Fig. 6.

Equisetum myriochaetum, transverse sections showing stomatal development (all LM). (A) Part of a young stem showing rib and meristemoids. (B) Detail of a meristemoid. (C) Meristemoids undergoing the first asymmetric division. (D) Detail showing recent periclinal divisions of epidermal cells. (E) An intervening cell undergoing periclinal division. (F). Stomatal triad. (G) Detail of a differentiated stoma not yet showing silicified radiating ribs. gc, guard cell, m, meristemoid; ocl, outer cuticular ledge; p, pore; sc, subsidiary cell; st, stoma. Scale bars = 50 μm in (A), 10 μm in (B), (D), (G), 20 μm in (C), 5 μm in (E), (F).