Conyza bonariensis (L.) Cronquist - Asthma-Weed

Conyza bonariensis plant

Family - Asteraceae


Conyza bonariensis plant


Conyza bonariensis leaves




Conyza bonariensis involucre

Ray flowers:

Mostly absent.

Disk flowers:

Conyza bonariensis flowers

Flowering - June - October.

Habitat - Waste ground, disturbed sites, roadsides, railroads.

Origin - Native to tropical America.

Other information - This scuzzy weed can be found mainly in the southern half of Alabama. It is likely to be much more common than has been reported. The plant can be identified by its villous stems, thin, dense leaves, uniseriate involucres, and small flower heads. The heads of flowers are noticeably larger, however, than the more common C. canadensis (L.) Cronquist.
The species epithet bonariensis refers to where the plant is thought to have originated (Buenos Aires). The Latin "ens(is)" means "belonging to."
The genus name Conyza was a name used by Pliny and Dioscorides for a type of Fleabane (genus Erigeron). Kunz reported that the name perhaps came from the Greek "konops." It is far more likely that the genus name Conyza is a bastardization of the Greek word "coryz(a)" meaning "a running at the nose" becasue the genus is a major cause of hay fever.

Alabama Distribution:

Conyza bonariensis map

Photographs taken off Lee Rd 54, Lee County, AL., 8-31-04.

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