Streptolirion is a genus of climbing monocotyledonous flowering plants in the dayflower family

Commelinaceae

Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with an estimated 650 species in 40 genera. Well known genera include...

. It consists of a single species, namely Streptolirion volubile. It has a broad distribution in Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, from China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

's western Hubei Province  as well as Korea

Korea

Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...

 and Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 in the northeast, south to Vietnam

Vietnam

Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

 and west to India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

. Currently two subspecies are accepted: S. volubile subsp. volubile and S. volubile subsp. khasianum, with the latter being a stronger climber covered with erect brown hairs. Streptolirion can be distinguished from the closely related climber Spatholirion

Spatholirion

Spatholirion is a genus of climbing or rosette monocotyledonous flowering plants in the dayflower family. It is distributed from China in the north, south to Thailand, Vietnam, and northern Peninsular Malaysia. It has four to eight seeds per carpel, unlike the closely related Streptolirion, which...

by the former's two-seeded carpels and inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

s that are all subtended by large involucral bract

Bract

In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...

s. They bear yellow hairs below the anthers, which are believed to increase floral attraction by contrasting with the petals or suggesting additional pollen is present. Despite the large range, an analysis of chromosomes found major differences between Japanese and Indian populations, suggesting that additional species may be as of yet unrecognized.