''Asarum asperum'' is a species of flowering plant in the pipevine family,

Aristolochiaceae The Aristolochiaceae () are a family, the birthwort family, of flowering plants with seven genera and about 400 known species belonging to the order Piperales. The type genus is '' Aristolochia'' L. Description They are mostly perennial, her ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Japan, where it is found on

Shikoku is the smallest of the List of islands of Japan#Main islands, four main islands of Japan. It is long and between at its widest. It has a population of 3.8 million, the least populated of Japan's four main islands. It is south of Honshu ...

and in the western regions of

Honshu , historically known as , is the largest of the four main islands of Japan. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the list of islands by area, seventh-largest island in the world, and the list of islands by ...

. It is particularly common in the vicinity of

Kyoto Kyoto ( or ; Japanese language, Japanese: , ''Kyōto'' ), officially , is the capital city of Kyoto Prefecture in the Kansai region of Japan's largest and most populous island of Honshu. , the city had a population of 1.46 million, making it t ...

and

Nara The National Archives and Records Administration (NARA) is an independent agency of the United States government within the executive branch, charged with the preservation and documentation of government and historical records. It is also task ...

. It is a perennial that produces thick evergreen leaves, which are ovate-orbicular and have a subhastate base. It produces ground-level maroon flowers, that are pollinated by insects. The flowering tube is prominently constricted at its apex. It blooms in April. It forms colonies on the

forest floor The forest floor, also called detritus or wikt:duff#Noun 2, duff, is the part of a forest ecosystem that mediates between the living, aboveground portion of the forest and the mineral soil, principally composed of dead and decaying plant matter ...

, where it often grows co-occurs with '' Ainsliaea cordifolia'', with which it bears a resemblance. File:Asarum asperum2 (cropped).jpg, Detail of flowers

References

{{Taxonbar, from=Q15545355 asperum Endemic flora of Japan Plants described in 1932