LD 123 "A wood of birch trees, standing tall, ...

I saw this in passing this morning and took a picture because it reminded me of something which I couldn't quite place.

Then it came to me :

"Hallaig is where they survive, 
All the MacLeans and MacLeads 
Who were there in the time of Mac Gille Chaluim: 
The dead have been seen alive, 

The men at their length on the grass 
At the gable of every house, 
The girls a wood of birch trees 
Standing tall, with their heads bowed."

The birch features again and again in that wonderful poem,  and this translation is by the great Seamus Heaney.