Nymphaea × helvola

Nymphaea × helvola is an artificial waterlily hybrid of Nymphaea mexicana with Nymphaea tetragona^[2][1] or Nymphaea pygmaea,^[3][4][5][6] which has been naturalised in India.^[7][8]

Nymphaea × helvola is a rhizomatous,^[9] perennial,^[10] aquatic^[11] herb.^[10] The small,^[6] dark green,^[12] oval^[13] to orbiculate leaf with an entire margin^[14] is 5^[13]–12 cm long,^[15] and 7 cm wide.^[13] The leaf displays brown to red marbling and spotting.^[12]

The small,^[6] yellow,^[14] fragrant,^[14][15] 3–4 cm wide flowers^[16][12] float on the water surface.^[5][12] The sepals are green on the abaxial surface and yellow on the adaxial surface.^[13] The flowers have 16–19^[13][12] lanceolate,^[12] 2 cm long, and 1 cm wide petals.^[13] The stamens are yellow.^[12]

It was described by Maurice de Vilmorin in 1891.^[1][17] It is placed in the subgenus Nymphaea subg. Nymphaea.^[3]

The hybrid name helvola means pale yellow.^[18][19] The flowers are pale yellow.^[11]

It is a hybrid of Nymphaea mexicana with Nymphaea tetragona^[2] or Nymphaea pygmaea.^[3][4]

It has been naturalised in Tam Dil, Mizoram, India.^{[7][8][20][21]}

It is cultivated in small ponds, small water gardens,^[9] and aquaria^[6][22] in shallow, 20–25 cm deep water.^[16][23]