On June 2nd, 2006 Thailand's national tree Golden Shower Tree (Cassia fistula) was presented and planted in the greenhouses by the Thai ambassador in Denmark, Chaisiri Anamarn. The tree was a gift from the Royal Thai Embassy on the occasion of King Bhumibol Adulyadej's 60 year jubilee, and was donated as a symbol of the long and close relation between Thailand and Denmark.

For many years there has been a very close collaboration of Thai and Danish botanists at the Herbarium of the University of Aarhus. The collaboration includes collection and description of the Thai Flora. It is estimated that the Thai flora includes approximately 11.000 plant species. The Danish flora for comparison includes about 1500 species. It is obviously a very important collaboration.

The Thai ambassador Chaisiri Anamarn presents Thailand's national tree to professor Henrik Balslev, Aarhus University in 2006. The Thai ambassador Chaisiri Anamarn presents Thailand's national tree to professor Henrik Balslev, Aarhus University in 2006. 

At the time the tiny tree was planted in the original tropical house of the greenhouses where, now, there is exhibition, shop, and café. In 2012 the tree was moved, together with all the remaining plants into the new Tropical house. The tree fortunately survived the transplanting and thrives very well in its new surroundings.