Gentiana clausa wani nau'in shuka ne na furanni a cikin dangin Gentianaceae. An fi saninsa da rufaffiyar kwalaben genian ko ƙwalwar ganye. Wannan tsiron asalinsa ne a gabas da tsakiyar Arewacin Amurka kuma ana samunsa sau da yawa a wurare masu dausayi, ciyayi, da gefen rafuka. Rufaffen kwalbar gentian ta sami sunan ta gama gari saboda furanninta suna da rufaffiyar, mai siffar kwalabe wanda ke buɗewa kawai lokacin da mai yin pollinator, kamar bumblebee, ya sauka a kai kuma ya tilasta ta buɗe. An yi amfani da shukar a cikin magungunan gargajiya don magance cututtuka iri-iri, gami da matsalolin narkewar abinci da zazzabi.