There are about ten thousand plants in the glasshouse, so I can only mention but a few.
Musella lasiocarpa, the lotus flowered banana, so named because its flower resemble a lotus flower, is an Asian plant which is used as a source of healing herbs and its leaves are used for weaving fabrics. In an age when manmade fibres are becoming less viable, as they are oil-based, we will need natural alternatives. The plant is good for erosion control on steep hillsides, as it has strong and widespread roots.
Another plant with medicinal use is Dioscorea deltoidea, the Nepal yam. This is an indeible yam,but its roots, vigorous rhizomes, are a source of steroids with medicinal uses, some of which are anti-inflammatories. Kew is preserving this plant so that its seeds can be collected and used in medicinal research.
Some are extinct in the wild. Take the case of Abutila pitcairnense, the yellow fatu. Native to Pitcairn Island in the Pacific, the refuge of the Bounty Mutineers, it is extinct in its native home due to predation by goats and rats, and its only home is now Kew. Another endangered one is Banksia brownii, which is an Australian plant with reddish brown flowers whose seeds break their dormancy in bushfires, which serve to spread them. In its native land it is endangered by development, so its being protected at Kew.
Or let's turn to the tree on whose leaves Robinson Crusoe might have looked. Alexander Selkirk, a privateer [legal pirate permitted to raid the king's enemies] had no confidence in his equally villainous, but incompetent captain and so asked to be marooned on Juan Fernandez Island off South America, where he remained three and a half years. He was wise, for the ship sank and the crew were captured by the Spanish, who were not pleased with English pirates..There Selkirk, one of the men on whom Defoe based his tale of Robinson Crusoe, fed on goats introduced to the island as food supplies by British privateers and whatever else he could eat. The cabbage tree, Dendroseris lioralis, has large cabbage shaped leaves which are excellent goat food, though they are too rubbery for humans to digest. Found only on Juan Fernandez this small, easily cultivatable tree is easily stripped of its leaves by goats, so it is being propagated at Kew. By the way, the name cabbage tree is a popular colloquial, non-scientific name applied to a few different species of tree.
Ten thousand species is more than I can detail here, but I hope that you can get a taste of the Temperate House, a sip from the wine cellar of horticultural glory.It opens tomorrow, fifth of May 2018, in time for the Spring bank holiday weekend. Expect it to be busy!