Drepanophycus spinaeformis is an extinct species of small Lycopodium-like plant which lived 410 to 390 million years ago in the early Devonian period of the Paleozoic era. First discovered in Scotland, D. spinaeformis remains have since been recovered in Russia (around Lake Shunet in the republic of Khakassia), in the Yunnan province of the People's Republic of China, and in Egypt. They were among the earliest land plants.
The plants grew to approximately 80 cm in height and are notably differentiated from other plants in the Drepanophycus genus
by their thicker stems. Foliage is described as firm and spiny, though recovered fossils rarely retain leaf detail. The stomata
of D. spinaeformis
look similar to that of Lycopodium japonicum
. They both consist of two large guard cells and pore, and are anomocytic. There were two small guard cells surrounded by two large similarly shaped subsidiary cells (paracytic) deriving from a pronounced elliptical cuticular ledge on the surface of the guard cells surrounding a thickened circumporal area.
- Cheng-Sen Li, F. M. Hueber, and C. L. Hotton (2000) A neotype for Drepanophycus spinaeformis Göppert 1852. ''Canadian Journal of Botany v. 78, p. 889–902.
- Tong-Xing Sun, D. Edwards & Cheng-Sen Li (2005) The stomatal apparatus of Lycopodium japonicum and its bearing on the stomata of the Devonian lycophyte Drepanophycus spinaeformis. Botanical Journal of the Linnean Society v. 149, p. 209-216