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The stomatal apparatus of Lycopodium japonicum and its bearing on the stomata of the Devonian lycophyte Drepanophycus spinaeformis.
by Sun T.-X., Edwards D., Li C.-S. (2005)
Tong-Xing SUN, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing
Dianne EDWARDS, School of Earth, Ocean and Planetary Sciences, Cardiff University, UK
Cheng-Sen LI, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China
in Bot J Linn Soc 149 209–216. –
Abstract
The structure of the stomatal apparatus of the leaf of Lycopodium japonicum Thumb was studied using epidermal macerations, sections and scanning electron microscopy. The stomatal apparatus of L. japonicum consists of two large guard cells and pore, and is anomocytic.
Based on light microscopy, the impression from epidermal macerations that there were two small guard cells surrounded by two, large, similarly shaped, subsidiary cells (paracytic) derives from a pronounced elliptical cuticular ledge on the surface of the guard cells surrounding a thickened circumporal area.
A similar appearance is characteristic of cuticle preparations of the Devonian lycophyte Drepanophycus spinaeformis Göppert. We therefore conclude, as did W.H. Lang over 70 years ago, that the stomata of the early lycophyte were also anomocytic, as were those of a second species of Drepanophycus, D. qujingensis Li & Edwards.