Canadian Fleabane - Conyza canadensis

    Description

    Short to tall hairy plant to 1.5 metres, leaves alternate, narrow, oblong, and the lower often deciduous before flowering. Flowers 2 to 5 mm with white ray florets scarcely longer than the yellow disk florets, borne in branched clusters. The phyllaries are more or less hairless in this species unlike the similar Guernsey Fleabane which has hairy phyllaries.

    Similar Species

    There are 3 very similar Conyza (syn - Erigeron): Guernsey, Bilbao's and Argentine Fleabanes.  Separating them is tricky; reference should be made to the key in Stace (4th edition)

    Identification difficulty
    ID guidance

    Phyllaries yellowish-green; more or less glabrous and with a 4-(5)-lobed corolla. Inflorescence is cylindrical. Outer flowers have ligules overtopping phyllaries.  Hairs on proximal part of leaf-margin (closest to leaf-stalk) are more or less straight; curved on rest of margin.

    The very similar Bilbao's fleabane (C floribunda) has 5-lobed corollae, and ligules of outer flowers scarcely overtopping phyllaries; the inflorescence is narrow but widens above.  It has been recorded in VC55.

    Recording advice

    The County Recorder has asked for a specimen of this plant to be retained for verification

    Habitat

    Cultivated and waste places, walls. Often in built up areas.

    When to see it

    July to September.

    Life History

    Annual.

    UK Status

    Only common in England, scarcer elsewhere in Britain.

    VC55 Status

    Fairly common and probably increasing in built up areas of Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 36 of the 617 tetrads.

    Leicestershire & Rutland Map

    UK Map