Tropical greenhouse

The ex-libris of the Botanical Garden of the University of Porto's aquatic plants - the Victoria cruziana, deservedly known as the ‘Queen of the water lilies’ - grows and flourishes in the Tropical Greenhouse's lake. This species is native to Argentina, Bolivia, Paraguay and southern Brazil, where it grows in shallow, still streams associated with the Atlantic Forest and the Pampas. Its leaves can reach up to 2 metres in diameter, with upward-facing leaf margins about 20 cm high. The underside is covered in spines, which protect it from herbivores, and thick, hollow, protruding veins, which form small air chambers that increase its ability to float. But it is the flower of this water lily that delights us on the evenings spent in the Tropical Greenhouse, both because of its rapid opening, its size, colour and aroma, but also because of its interesting pollination strategy. In the same pond, the spiny water lily (Euryale ferox) is cultivated, which grows naturally in shallow bodies of fresh water from northern India to the far east of Russia, Japan and Taiwan. This species has all its structures covered in thorns, with the exception of the flowers. Its seeds, known as makhana, are edible and have been widely consumed since the Neolithic period, raw or cooked in China and Southeast Asia, as a food source or in Ayurvedic and traditional Chinese medicine.