Flowering biology of Galeobdolon luteum (Lamiaceae) in Moscow region

Abstract

Background. Galeobdolon luteum Huds. (Yellow archangel) is a perennial creeping herbaceous short-rhizome polycarpic plant. Literature information on the biology of flowering and pollination in G. luteum is scarce. Materials and methods. Our observations were carried out in natural conditions of the Moscow region from 2019 to 2021 according to generally accepted methods. Results. G. luteum forms two types of inflorescences: an apical open thyrsus and an intercalary inflorescence, the floral zone of which is an open thyrsus. Thyrsus subunits are cymoids represented by 3-flowered, rarely 4-, 2-, or 1- flowered dichasia. The flowers of G. luteum are slightly protandrous or adichogamous. The lifespan of the flowers is 3-7 days. G. luteum has a daily flowering rhythm, in which the flowers open during almost the entire daylight hours. Conclusions. G. luteum has a complex of morphological features of flowers and inflorescences characteristic of melittophilous plants. Such features include bright color of flowers, large zygomorphic flowers with a prominent and stable landing area, anthers and receptive surfaces of the stigma are hidden under the upper lip, the presence in ring of hairs (nectarostegium), deep location of nectaries, formation of compact, stable and durable thyrsi for insects.

Keywords

• galeobdolon luteum
• flowering biology
• entomophily