Andromonoecy and developmental plasticity in Chaerophyllum bulbosum (Apiaceae–Apioideae)

Background and Aims: Andromonoecy, the presence of hermaphrodite and male flowers in the same individual, is genetically fixed or induced, e.g. by fruit set. Little is known about the forces triggering andromonoecy in the Apiaceae. In the present study, a natural population of the protandrous Chaerophyllum bulbosum was investigated to elucidate architectural constraints and effects of resource reallocation. Methods: Three sets of plants (each n ¼ 15) were treated by hand pollination, pollinator exclusion and removal of low-order inflorescences. Fifteen untreated plants were left as controls. Key Results: Untreated plants produce umbels up to the third branch order, with increasing proportio…