Cycas revoluta Thunb.Cycadaceae
From East Asia, southern Japan, eastern China and Java, it has the appearance of a palm tree, although it belongs to a different plant group and much more primitive, which had its grand climax in the Mesozoic Era, coinciding with the dominance of dinosaurs; then decreased dramatically with the evolution of flowering plants, hence the king sago palms are considered authentic living fossils. There are good examples and well preserved in the gardens of the Real Alcázar. The superficial resemblance of the king sago palm with the palm made that it was formerly called cicopalma, and even Linnaeus when naming it generically also believed it was a palm, because in old Greek the term kukas designated an unidentified type of palm and thus appears in a classic manual of ancient botany, History of Plants by Theophrastus (372-287 BC). The specific name revoluta refers to the spiral shape, and coiled, of its leaves. In its native Asia it is used as a facing wall for temples. Seeds are consumed as food, but it is proven that it has a carcinogen substance in its seeds, the cicadina. However, from the core of its stem it is extracted the sago from Japan used for human consumption. Its roots also have nodules of blue-green algae able to fix atmospheric nitrogen.