Floating leaves 1-3 x 1.5-4 cm, dentate, glabrous above, pubescent to villous below, especially on the nerves; petiole up to 10 cm long, dilated near the leaf base, villous. Sepals c. 5 mm long, ovate, villous, especially in the middle portion. Petals c. 8 mm, white. Fruit 1.3 x 1.7 cm, excluding spines; spines 4, 1-1.3 cm long, two of which are shorter.

Fl.Per.: July-September. Fr. Per.: September-October.

Type: Described from France, Switzerland, and Italy (Hb., Linn. 158/1).

Distribution: Europe; Asia; N. & C. Africa.

Found in the Kashmir Valley Lakes at c. 1700 m, but has not been collected from our area so far.

This water chestnut is distinguished from Trapa bispinosa by its smaller leaves, not densely villous and a 4-horned fruit, all the angles of the fruit being spinescent.

V.N.Vasil’ev has split Trapa natans L. into 3 species, Trapa quadrispinosa Roxb. Trapa asiatica V.Vasil. and Trapa indica V. Vasil. and has selected R.R. Stewart 3351 ½ (RAW) as the lectotype for Trapa quadrispinosa Roxb.