The doors of the first greenhouse open onto a pool heated to 30°C at the start of the year and 27°C in summer and dedicated to presenting tropical aquatic plants:
- Floating, aquatic and semi-aquatic plants (or marsh plants) illustrate the many different ways in which plants adapt to living in water.
The giant Amazonian water lily (Victoria cruziana), with its impressive leaves in the shape of a pie dish, may be seen from May to October.
- The second theme covered here is that of invasive exotic plants in a tropical environment, with the water hyacinth (Eichhornia crassipes) and the water cabbage (Pistia stratiotes).
At the far end of the pool, a rich, original ecosystem known as the mangrove is recreated. A number of mangrove trees are exhibited:
- Rhizophora, which have stilt-like roots.
- An Avicennia with roots that grow upwards to allow the plant to “breathe” beyond the suffocating soil. They are known as cypress knees.
The greenhouse is also home to a large number of epiphytic species (plants that live on other plants that they use as a support, without being parasitic). For example, tillandsia or “old man’s beard” (Tillandsia usneoides) hangs on branches and wires and captures the moisture in the air.
Finally, the number and variety of the bromeliaceae (pineapple family) are highlighted with the tillandsias and other genuses presented on a landscaped slab and in epiphytic condition on trees.