Index Seminum is the name of the list or catalogue used by an international network of botanical gardens to exchange seeds with each other. Seeds are exchanged for the purposes of science, pedagogy and nature conservation. They are not commercially available outside the network. Botaniska starts collecting seeds in the summer and continues this work until November.
The Botanical Garden in Gothenburg exchanges seeds with 650 institutions worldwide, mainly in Europe. Botaniska's catalogue lists 300 – 350 different seeds or figures every year. Since 2008, curator Henrik Zetterlund has been responsible for which seeds to collect and put on offer:
"My main criterion is only to list plants that I myself would like to order. We prioritise plants whose origins we know. Most of these are found in Botaniska's Rock Garden, Bamboo Thickets, Bulb Garden and Cold Greenhouses. When we've been out on collecting trips around the world, we distribute our surplus seeds and plants to neighbouring gardens. It is particularly gratifying to see our collections in other gardens ", says Henrik.
Botaniska's Archive holds the garden's documented index since 1919, with a break during the second world war, in 1941 and 1942. Other botanical gardens order on average 30 – 40 seed portions from every number of the Catalogue and every year 8,000 – 10,000 seed portions all in all are sent from Gothenburg out into the world.