Gynnidomorpha alismana, the water plantain conch, is a moth of the family Tortricidae.

It is found in most of Europe, except Spain, Switzerland, most of the Balkan Peninsula and Ukraine.

Further east it is found across the Palearctic to China (Anhui, Fujian, Guangdong, Guizhou, Hebei, Heilongjiang, Hubei, Hunan, Inner Mongolia, Jiangxi, Jilin, Shaanxi, Yunnan) and Korea.

Forewings with a gently arched costa .They are pale ochreous, submetallic, the margins more or less strigulated with dark fuscous > There is an ochreous-brownish basal patch, often represented by an angulated edge only.Then a slightly curved ochreous-brown median fascia, suffused with blackish below middle.

The larva is dull yellowish -pink or pinkish-brown; head and plate of 2 black-brown :[5] Adults are on wing from June to August.