The exhibition greenhouse is divided into two main collections: the dry area and the humid area. Plants from warm regions all over the world are grouped here in order to show visitors the great floristic diversity of these environments, which include some of the world’s biodiversity hotspots.

DRY AREA

The dry area comprises four central beds containing different species grouped according to their geographical origin. Here we find plants typical of the deserts of the Americas (cacti and other succulents, arranged in separate beds), Africa (aloes, kalanchoes, euphorbias, among others), and the most arid zones of the Canary Islands, represented by dragon trees (Dracaena draco), aeoniums (Aeonium), verodes (Kleinia neriifolia), cardón spurges (Euphorbia canariensis), cardoncillos (Ceropegia fusca, C. dichotoma), white tajinaste (Echium decaisnei), among others. In general, many of the plants found in this section of the greenhouse possess water-storage tissues and organs as an adaptation to the arid environments in which they live.

Carnivorous plants. In one of the lateral beds of the dry area of the greenhouse, a small collection of carnivorous plants has been established. These species require an additional protein intake, as they inhabit substrates that are extremely poor in nutrients (epiphytically on rocks and tree branches, in highly acidic soils, or in waterlogged environments). Species with different insect-capture mechanisms have been selected: pitcher-shaped traps (Nepenthes, Sarracenia), snap traps that close when a small animal touches one of the trigger hairs (Dionaea muscipula), and sticky leaves (Pinguicula, Drosera, among others).

HUMID AREA

The high atmospheric humidity and warmth that greet visitors upon entering this environment provide an immediate impression of the ecological conditions in which tropical rainforest plants develop.

In one of the central beds, there is an interesting collection of ferns, including tree ferns—plants without flowers or seeds that colonised and dominated the Earth’s vegetation during the Palaeozoic era (around 290 million years ago). Another bed displays the oldest gymnosperms (which emerged approximately 280 million years ago), the first seed-producing plants in the history of life on Earth: cycads, true living fossils, represented by species such as Cycas revoluta, Dioon spinulosum and Zamia furfuracea. A third bed contains a small collection of palms (modern monocotyledons), while a fourth presents herbaceous species characteristic of the Canarian laurel forest, such as Geranium canariense, Canarina canariensis and Dracunculus canariensis, together with larger species typical of tropical rainforests, such as banana plants (Musa acuminata var. Cavendish), white bird-of-paradise (Strelitzia nicolai), pachiras (Pachira aquatica) and umbrella trees (Schefflera actinophylla), as well as several orchids (Phalaenopsis).