I'll copy the information here from that great Irish Times article, thanks Thompson- in case it stops being accessible.

The Words We Use
Sat, May 3, 1997, 01:00
DIARMAID O MUIRTHE

Oh were I at the moss house where the birds do increase, At the foot of Mount Leinster or some silent place, By the streams of Bunclody, where all pleasures do meet, And all I would ask is one kiss from you, sweet.

Ann Byrne wrote to me recently from Melbourne about the lovely song. She wants to know what a moss house is. She can thank the Wexford historian Rory Murphy and a sweet Bunclody lady, Sarah O'Hara, for answering a question that has been bothering myself for years. Sarah tells me that the moss house in question was made in the last century by Lady Lucy Maxwell on the Carrigduff side of the Slaney at Bunclody. It was made from actual growing trees which were bent over and intertwined to form a beautiful living summerhouse. Several low, shrub-like trees decorated the floor, which was carpeted with thick, soft moss. Hence the name.

Does the beautiful moss-house still exist, the arbour where the young man, wounded in love, wanted to die on the bosom of his beloved? Alas, no. Vandalism has seen to that.

Who were they anyway, the young lovers? She, I once heard, was one of the Maxwells. Maybe. It is why my love slights me, as you may understand, That she has a freehold and I have no land; She has great store of riches and a large sum of gold, And everything fitting a house to uphold.

And who was he? Does anybody know? Mary Byrne and I would love to.