Morphological and histochemical investigations on Himantoglossum robertianum (Loisel.) P. Delforge (Orchidaceae) seeds.

In the present study, the morphological and histochemical properties of Himantoglossum robertianum (Orchidaceae) seeds were investigated. According to the morphological studies, the testa cells are dead and show reticulations. According to the histochemical tests, mature embryos were globular and covered with cuticular sheath in especially on the embryo parts of the seed. Furthermore, high amounts of soluble carbohydrates, lipid and protein bodies were found in mature embryos; but very little of starch was found. Consequently, the present results are important for both European-Mediterranean terrestrial orchids and present taxon, H. robertianum; thus they are discussed from the point of view of seed germination physiology and orchid embryology. [ABSTRACT FROM AUTHOR]