South Africa 2024
In November 2024 Gothenburg Botanical Garden’s Professor Anthony Verboom and Scientific Curator Kent Kainulainen travelled to South Africa to collect plants in the Western Cape.
This trip was planned together with colleagues from the Bolus and Compton Herbaria in Cape Town. For two weeks we travelled the mountain regions of the Cape visiting the Cederberg, Jonkershoek, Langeberg, Outeniquas, Riviersonderend, Swartberg, and many other locations. The primary purpose was to collect material for ongoing research on the plant families Asteraceae, Cyperaceae, and Poaceae. Recent genomic research on the hyperdiverse and largely endemic Cape Flora has revealed that previously assumed widespread species instead comprise complexes of multiple, narrowly distributed species. On this field trip we focused on three genera, Ehrharta (Poaceae), Osteospermum (Asteraceae), and Tetraria (Cyperaceae), sampling leaf material for genomic research to quantify patterns of genetic diversity for the purpose of identifying potential long-term climatic refugia and to test for the potential existence of multiple species.
Most of the localities that we visited were part of the fynbos, which is a fire-prone heathland that occurs on extremely nutrient-poor soils. Fynbos is an ancient vegetation type within the Cape, in which fire is the major disturbance and plays a central role in maintaining the system, particularly through its effect on the soil nutrient dynamics. A secondary goal of this trip was to identify and sample seeds of a selection of species representing alternative post-fire regeneration strategies for propagation at Botaniska.
Asteraceae is ubiquitous in the fynbos, and the diversity of this plant family is bewildering, such as the tiny moss-like lithophyte Muscosomorphe, or Corymbium which at first glance is easily mistaken for a monocot because of its tufts of straplike leaves with parallel venation. We also found several species of Osteospermum, including O. moniliferum - a common species, but with a trait that is very unusual within Asteraceae: fleshy fruits. The fruits attract birds that help disperse its seeds. Unmistakable in the Boosmansbos mountains is Osteospermum corymbosum, a short-lived shrub with a with a rigid erect stem - often without branches - and an umbelliform apical inflorescence that towers over the otherwise low vegetation.
We look forward to displaying some of these species at Botaniska once construction of the new greenhouses is completed – a tiny fraction of the diversity of the fynbos flora.
Kent Kainulainen and Tony Verboom
