Cardiocrinum cordatum var. glehnii is a large perennial herbaceous plant in the family Liliaceae, native to northern Japan, including Hokkaido, as well as parts of the Russian Far East. It is commonly known as the giant heart lily or ōubayuri (オオウバユリ) in Japanese. The genus name Cardiocrinum derives from Greek kardia (“heart”) and krinon (“lily”), referring to the heart-shaped leaves characteristic of the plant, while the species epithet cordatum also means “heart-shaped” in Latin. The varietal name glehnii honors the Russian botanist Peter von Glehn, who studied the flora of northeastern Asia. This plant grows in cool, forested mountain environments where it develops large bulbs and tall flowering stalks.

The plant produces broad, heart-shaped leaves and a tall inflorescence bearing multiple large, trumpet-shaped white flowers with a strong fragrance. Like other members of the lily family, it grows from an underground bulb that stores nutrients, allowing it to survive in seasonal climates. Cardiocrinum cordatum var. glehnii is notable for its long growth cycle, often taking several years before flowering, after which the main bulb dies while producing offsets.

As a food source, the bulb of Cardiocrinum cordatum var. glehnii has been traditionally used in parts of northern Japan, particularly by the Ainu people. The bulbs are rich in starch and were historically processed to produce flour or starch used in dumplings, porridges, or other staple foods, especially in environments where cereal agriculture was limited. Preparation typically involves harvesting, crushing, washing, and refining the bulb material to remove bitterness and concentrate usable starch.

Chemically, the bulb contains high levels of starch as its primary storage compound, along with smaller amounts of sugars, fiber, and micronutrients. Like many wild plant bulbs, it may also contain bitter or mildly toxic compounds that require processing to render it palatable and safe for consumption. While specific bioactive compounds are less extensively characterized than in more widely cultivated food plants, the nutritional role of the bulb has historically been as a carbohydrate source.