Heliades (English spelling)

...When he met his father as an adult for the first time, he was told that any wish he had would be granted, so he borrowed his father's chariot for one day and set off into the sky, but he did not know how to control the wild horses, and when the fiery chariot went off the track and nearly burned the earth, Zeus' thunderbolt shot it down into the Eridanos River. His sisters, the Heliades (daughters of the sun god), gathered on the riverbank at this time and mourned his death, turning into poplar trees, and their tears solidified into amber. The Eridanos River was originally thought to be a great river that flowed into the North Ocean, and later was identified with the Po River, but this river, which has the Electrides (Amber) Islands at its mouth, is thought to retain the memory of the so-called Amber Road, a trade route when amber, which is only found in the Baltic Sea in Europe, entered the Mediterranean world during the Bronze Age. ...

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

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…成人してはじめて会った父神に，どんな願いもかなえてやるといわれた彼は，1日だけの約束で父の馬車を借りて大空に乗り出したが，荒馬を御すすべを知らなかったため，軌道を踏み外した火炎の車があやうく地を焼き払いそうになったとき，ゼウスの雷霆によってエリダノス川へ撃ち落とされた。このとき河畔に集まった彼の姉妹たちのヘリアデスHēliades(太陽神の娘たち)は，その死を悼んで嘆き続けるうちにポプラの木と化し，彼女たちの涙は凝固して琥珀（こはく）になったという。エリダノス川は古くは北洋に注ぐ大河と想像され，のちにはポー川と同一視されたが，河口にエレクトリデス(琥珀)諸島があるというこの川は，ヨーロッパではバルト海にしか産しない琥珀が青銅器時代の地中海世界に入ったときの交易路，いわゆる〈琥珀の道〉の記憶をとどめるものと考えられている。…

※「Hēliades」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