18th Annual Smithsonian Magazine Photo Contest Natural World
Singhara Nut (Trapa natans var. natans)

In this variety of the water chestnut, native to the Old World tropics, spines are developed from all four corners of the fruit, though with one pair longer than the other (in India it was therefore known to William Roxburgh as Trapa quadrispinosa). The fruit is ‘indehiscent’, that is its walls do not split open to release the seed, but gradually break down by decay or physical damage. The plant is a floating aquatic and the fruit sinks to the bottom of the pond, lake, or flooded field, where the seed within it can remain viable for up to 12 years.

Photo Detail
Date Taken: 02.2020
Date Uploaded: 08.2020
Photo Location: Edinburgh, United Kingdom
Copyright: © Levon Biss