Conyza sumatrensis (English spelling) Conyzasumatrensis

...The stem branches out in large branches and produces many small flower heads in large panicles. The flower heads have small white ray-shaped florets, so they can be distinguished from Conyza sumatrensis (Retz.) Walker. This is also a biennial plant that became naturalized in the early Showa period, and is often found on roadsides and wastelands. ...

*Some of the terminology that mentions "Conyza sumatrensis" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…茎の上部で多数分枝し，大型の円錐花序に多数の小さな頭花をつける。頭花には小さいが白色の舌状小花があるので，オオアレチノギクConyza sumatrensis (Retz.) Walkerと区別できる。これも昭和の初期に帰化してきた越年草で，道ばたや荒地に多い。…

※「Conyza sumatrensis」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報