Conyza bonariensis (hairy fleabane, "Arechinogiku")

Japanese name: アレチノギク （荒地野菊）
Scientific name: Conyza bonariensis

[Overview]
An annual or biennial found in fields, roadsides and vacant lots.
The whole plant is densely covered with grayish-white hairs.
When the stem has grown to 30–50 cm, the main stem stops growing and an inflorescence forms at its tip.
The side branches grow taller than the inflorescence.
There are basal leaves and stem leaves, and the basal leaves are deeply pinnately divided.
The stem leaves on the lower part of the stem are oblanceolate, pinnately divided halfway to deeply, with wavy margins.
The upper ones are oblanceolate to linear, 5–13 cm long and 0.5–2 cm wide, with an entire margin or sparse teeth.
The leaves on the lower part of the stem have usually withered by flowering time.
The inflorescence at the stem tip bears many flower heads in a raceme.
The flower heads are white or dark purple and have many ray florets, but these are small and inconspicuous, so the flowers appear to have no petals.
The involucre is about 5 mm.
The fruit is an achene with a white to pale brown pappus.

[History]
It is widely naturalized in the temperate to tropical regions of the world.
It arrived in Japan in the middle of the Meiji era and was widely seen throughout the country in the Taisho to early Showa eras, but it has become less common in recent years.

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