Herbarium-based study of flowering and fruiting phenology of twelve indigenous and endemic plant species from Ethiopia

Abstract

Herbarium specimens are being used as reliable sources for estimating phenological behavior for plant species. Flowering and fruiting periodicity of 520 herbarium specimens, collected between 1948 and 2007 and deposited at the National Herbarium of Ethiopia, were investigated. Scientific names, collection date and locality of specimens were documented to assess the periodicity of phenological events. For the evaluation of periodicity of reproductive phenophases, the presence of flowering and fruiting were visually confirmed from each specimen. Examination of flowering periodicity of Bersama abyssinica, Brucea antidysenterica, Maytenus arbutifolia and Rosa abyssinica showed continuous flowering while Prunus africana, Lobelia rhynchopetalum, Kniphofia foliosa, Solanecio gigas, Buddleja polystachya, Dombeya torrida and Embelia schimperi exhibited seasonal flowering. Although the fruiting period is extended over several months (B. abyssinica, B. antidysenterica, E. schimperi, M. arbutifolia and R. abyssinica), seasonality in fruiting was also observed in K. foliosa, L. rhynchopetalum and P. africana. The highest number of specimens found belonged to M. arbutifolia followed by B. abyssinca and B. antidysenterica, while the highest number of specimens were collected from Shewa Upland followed by Keffa and Bale floristic regions. Surprisingly, Euryops pinifolius, a species endemic to Ethiopia, was represented by only one specimen collected from Gojjam in 1985. The results revealed that herbarium specimens can be used to study flowering and fruiting periodicity of plant species. Therefore, botanists should be encouraged to continue collecting herbarium specimens based on the distribution of species in the flora area to avoid spatial and species biases for future studies.