Flowering biology of Heracleum sibiricum (Apiaceae) in Moscow region

• Main Authors: V.N. Godin, T.V. Arkhipova, J.I. Ialamova
• Format: Article
• Language: English
• Published: Penza State University Publishing House 2021-07-01
• Series: Известия высших учебных заведений. Поволжский регион: Естественные науки
• Subjects: flowering biology; umbel; heracleum sibiricum; apiaceae

Background. Species of the large genus Heracleum L. are characterized by a variety of flowering patterns and the degree of its study. Heracleum sibiricum L. forms perfect, staminate and pistillate flowers, the flowering biology of which are absent in the literature. The purpose of this work is to identify the flowering biology of this species in the Moscow region. Materials and methods. Anthecological observations were carried out in natural conditions of Moscow region from 2017 to 2019, according to generally accepted methods. Results. There are four stages in the development of perfect and pistillate flowers (loose bud, staminate, sterile, stigma) and two stages in staminate flowers (loose bud and staminate). The life span of flowers gradually decreases in the row perfect – pistillate – staminate flowers and amounts to 4–8 days, 4–5 days and 1 day, respectively. The perfect, staminate, and pistillate flowers open synchronously with a maximum at 9 am. Conclusions. Each umbellet and umbelin its flowering successively passes through several phases: staminate – sterile – stigma, which is an adaptation to ensure cross-pollination of nonsynchronously flowering individuals in populations.