Youngia japonica

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Youngia japonica
A small wild specimen of Y. japonica in Japan
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Youngia
Species:
Y. japonica
Binomial name
Youngia japonica

Youngia japonica, commonly called Oriental false hawksbeard,[1] is a species of flowering plant in the family Asteraceae. Native to eastern Asia, it is now found as a weed nearly worldwide.

Description[edit]

It is an annual that produces yellow flowers. In tropical areas, it can bloom year round, while in temperate areas it blooms in late spring and early summer.[2] Plants are variable in height, ranging from 10 to 150 cm (4 to 59 in) depending on growing conditions. Stems are usually solitary and erect. Basal leaves are large a pinnately divided. Its fruits are wind dispersed.[3]

Distribution and habitat[edit]

Youngia japonica is native to eastern Asia in China and Japan.[3][4] However, it has been spread far from its initial range, and is now found as a non-native species nearly worldwide. It is present in Africa, Australia, Europe, North America, and South America.[2] In the United States, it is spreading rapidly, although it is largely restricted to areas in the Southeast.[5][6] It grows well in response to human disturbance, and is found in areas such roadsides, cultivated fields and in lawns.[2] In China, it is found in a variety of natural and disturbed habitats.[3] It is known to penetrate into intact natural communities as an invasive species in the United States.[5]

Taxonomy[edit]

Three subspecies are recognized. They are:[3]

  • Youngia japonica subsp. elstonii - With many stem leaves. Not known to be weedy.
  • Youngia japonica subsp. japonica - With few to no stem leaves. A weed found nearly worldwide.
  • Youngia japonica subsp. longiflora - Has larger flowers. Not known to be weedy. This is considered the most distinct subspecies.

It has been reported to form intergeneric hybrids with Lapsanastrum humile in Japan.[4]

References[edit]

  1. ^ USDA, NRCS (n.d.). "Youngia japonica". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 8 January 2018.
  2. ^ a b c Flora of North America, Youngia japonica
  3. ^ a b c d Flora of China, Youngia japonica
  4. ^ a b Ohwi, Jisaburo (1965). Flora of Japan. Washington: Smithsonian Institution. p. 930. doi:10.5962/bhl.title.43786. LCCN 65062683. OCLC 182709297.
  5. ^ a b Alan Weakley (2015). "Flora of the Southern and Mid-Atlantic States".
  6. ^ "Youngia japonica". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 8 January 2018.