Micromorphology and anatomy of fruits of Angelica archangelica L. (Apiaceae) and their intraspecific differentiation

Summary Introduction:Angelica archangelica L. (Apiaceae) has a long history of use as a vegetable and medicinal plant. According to the European Pharmacopoeia, the angelica root (Angelica radix) of only one of the sub-species – Angelica archangelica subsp. archangelica (formerly known as Archangelica officinalis) – is used as a source of plant material with documented medicinal properties. Within this species, there are two subspecies that are difficult to classify unambiguously: subsp. archangelica and subsp. litoralis. Objective: The aim of this study was to provide a micromorphological and anatomical description of fruits of A archangelica and identify new diagnostic characters useful in subspecies identification. Methods: A comparative analysis of the sculpture and internal structure of fruits of the distinguished A archangelica taxa was conducted, using scanning electron microscopy (SEM). Results: Based on the taxonomic characters in the Apiaceae family, micromorphological and anatomical characteristics of A archangelica fruits were prepared. Some of the investigated characters, e.g. verrucose sculpture of the oil duct surface and the presence of hooked hairs, exhibited intraspecific differences. Among the anatomical characters, the variation was related to the number and size of the paraendocarpic oil ducts as well as to the thickness of dorsal and commissural mesocarp. Conclusion: SEM examination of fruits of A archangelica provided a detailed description of their sculptures and several micromorphological and anatomical characters of potential diagnostic value.