''Conyza'' (horseweed, butterweed or fleabane) is a genus of
flowering plants in the family
Asteraceae.
They are native to tropical and warm temperate regions throughout the world, and also north into cool temperate regions in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
and eastern
Asia. The
New World species of the genus are closely related to ''
Erigeron'' (also known as fleabanes).
[Flora of North America, Horseweed, ''Conyza'' Lessing]
/ref>
The species are annual or perennial herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition of t ...
plants, rarely shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
s, growing to 1–2 m tall. The stems are erect, branched, with alternate leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
. The flowers are produced in inflorescences, with several inflorescences loosely clustered on each stem.[
Many species of the genus ''Conyza'' are ruderal species and some have been found to be resistant to the herbicide glyphosate.][
]
References
External links
Germplasm Resources Information Network: ''Conyza''
Chinese plant names: ''Conyza''
{{Taxonbar, from=Q828737
Astereae
Asteraceae genera
Ruderal species