On the unusual structure of the monocotyledonous embryo and seedling of Acronema commutatum H. Wolff (Apiaceae) and related species
Kljuykov, Eugeny V.; Zakharova, Ekaterina A.; Petrova, Svetlana E.; Tilney, Patricia M.
published: Apr 1, 2014
Acronema is a genus of about 25 species distributed in the high-altitude Sino-Himalayan region from North India to South-West China. The embryo morphology of eleven species and the seedling structure of A. commutatum were studied for the first time. All examined species have embryos with a single cotyledon. A new morphotype of the cotyledon for Apiaceae is described. Such a cotyledon has a trisect lamina and, in the seedling of A. commutatum, it is strikingly similar to the first foliage leaf. Three-lobed young cotyledons are found in the embryos of five Acronema species (A. commutatum, A. hookeri, A. paniculatum, A. muscicola and A. tenerum); the others have entire young cotyledons. It is shown that the presence of only one cotyledon is a diagnostic feature of the genus Acronema.