Euryale (plant)

Lore & Background

Euryale is an annual or perennial, rhizomatous, aquatic herb with erect, unbranched rhizomes. Its adaxial leaf surface is green with prickles at the veins, while the abaxial surface is violet with prominent, prickly venation. The thin, sharp prickles are 3–11 mm long and 1–2 mm wide at the base. The flowers are pedunculate, 5 cm wide, with prickly peduncles and sepals, and have four persistent sepals. The gynoecium consists of 7–16 carpels, and the prickly fruit bears 8–20 black, arillate seeds that are spherical, ovate, obovate, or ellipsoidal, 6–10 mm wide, with a hard, smooth, wrinkled, gnarled, or irregularly ridged testa.

Reader's Guide

Euryale is significant as a genus within the water lily family, with a single extant species, Euryale ferox, that is widely distributed from Northern India to the Russian Far East and temperate East Asia, and has recently been recorded in Serbia, likely dispersed by migrating birds. Its fossil record reveals a broader historical range across central Europe, with remains known from the Miocene of Poland, Russia, China, Germany, and the United Kingdom, the Pliocene of the Netherlands, Poland, Germany, and Italy, and the Pleistocene of Russia, Germany, Poland, Japan, China, Belgium, and Belarus. The genus is also notable for its evolutionary ties: together with Victoria, it may be placed within the genus Nymphaea, rendering it paraphyletic in its current circumscription. The lineage of Euryale and Victoria diverged from Nymphaea subg. Lotos and Nymphaea subg. Hydrocallis in the Miocene, and the two genera diverged from each other also in the Miocene. Ecologically, Euryale occurs in ponds, lakes, rice fields, and marshes, and its flowers are visited by flies and solitary bees. The seeds and petioles are used as food.

Did You Know?

• Euryale has only one extant species, Euryale ferox, but several fossil species, some of which may belong to the genus †Pseudoeuryale.
• The chromosome count of Euryale ferox is 2n = 58.
• Euryale seeds and prickles are well preserved in the fossil record, and pollen fossils are also known.
• The genus was published by Richard Anthony Salisbury in 1805.