Sonchus

...An annual or biennial weed of the Asteraceae family that is commonly found along roadsides and in fields throughout Japan (illustration). It is also known as poppy thistle or spring thistle. It is widely distributed throughout the tropical and temperate zones of Eurasia. The leaves are pinnately incised and have irregular teeth. They resemble poppies in the way that the leaves are powdery white all over and that they exude a white milky liquid when cut. They overwinter in rosettes, and in April and May, they grow soft, hollow stems about 40 to 100 cm tall, bearing a dozen or so yellow flower heads. The flower heads are composed only of ray florets and are about 2 cm in diameter. ...

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

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…日本全土の路傍や畑地にごく普通にみられるキク科の一･二年生雑草（イラスト）。ケシアザミまたハルノノゲシの名もある。ユーラシアの熱帯～温帯に広く分布する。葉は羽状に切れ込み，不規則な歯牙がある。葉形とともに全体に白粉を帯びる点，切ると白い乳液が出る点がケシに似る。ロゼットで越冬し，4～5月ころ，高さ40～100cmほどの軟らかい中空の茎を上げ，黄色の頭花を十数個つける。頭花は舌状花のみからなり，径2cm内外。…

※「Sonchus」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