Thanks, Jim Dixon.

By coincidence, today at work I found what I thought was a closely related song in a book of Welsh folk songs. However, having compared them, I'd say they aren't that close after all. The first stanza is almost identical except for being relocated from the Teifi to the Dyfi. I believe that this stanza has a long heritage - it's one of the Hen Benillion.

The Fernhill song is much longer than the one from the book. After the first stanza, I think the lyrics are almost entirely different, except that near the end Fernhill sing something similar to the second stanza given here - about passing by the nice flowers to cut a posy of stinging nettles.

Blewyn glas ar afon Dyfi
Ffa-rei-ti-rei-ta-ral
Ffal-di-ro-a-rei-ta-ral
Hudodd lawer buwch i foddi
Ffa-rei-ti-rei-ta-ral
Ffal-di-ro-a-rei-ta-ral
Lodes wen a'm hudodd innau
O'm hun iawn ffordd i'w chroesion lwybrau
Ffa-rei-ti-rei-ta-ral
Ffal-di-ro-a-rei-ta-ral

Mynd i'r ardd i dorri pwysi,
Pasio'r lafant, pasio'r lili;
Pasio'r pincs a'r rhosys cochion,
A thorri pwysi o ddanadl poethion

Mae dwy galon yn fy mynwes,
Un un oer a'r llall yn gynnes;
Un yn gynnes am ei charu,
A'r llall yn oer rhag ofn ei cholli.

Mi wrthodais, ffôl yr oeddwn,
Ferch a garai'r tir a gerddwn,
Ac a gerais, do'n garedig,
Ferch a'm gwerthai am ychydig.

Tyn dy gleddyf gloyw gwisgi,
Tor fy mhen, maddeuaf iti.
Gwell yw gennyf hynny'n dawel
Na rhoi fy llaw i ganu ffarwel.