Reproductive biology of Anthyllis vulneraria subsp. vulgaris (Fabaceae) in northwestern Iberian Peninsula

Abstract

In spite of being widely distributed throughout Europe, populations of Anthyllis vulneraria are very isolated genetically. As a consequence of processes of independent evolution, some isolated populations have developed characteristics that separate them from the rest. The scope of this study was to investigate whether or not this isolation has affected the reproductive biology. The reproductive biology of an isolated population of A. vulneraria subsp. vulgaris (Koch) Willk. in northwest Spain was studied, and compared with French populations. In the studied population, insect pollination was necessary for fruit production. Autogamy was precluded by protandry, although geitonogamous pollen transfer might occur. Supplementary pollination did not lead to any increase in fruit‐set level, seed‐pod weight or seed weight. Mean pollen/ovule ratio (3080) was within the normal range for xenogamous taxa. The first open flowers in capitula lived more than twice as long as later flowers did. During the floral life‐span, corolla colour gradually changed from white to partially pink to pink and the nectar production rate appeared to differ between colour stages. Fruit set level in the studied population differed between the four years of study. The breeding system found in this Spanish population differs from French populations. I suggest that classification of this taxon in northwest Iberian Peninsula should be reconsidered, taking into account its breeding system.