This is The Book of Taliesin, which I have been reading in the new translation by Gwyneth Lewis and Rowan Williams. Authors and dates for the poems it contains are impossible to identify, although they are ascribed to the shadowy figure of Taliesin, a sixth century bard associated with one or more of the leading royal houses of the Old North. Of course there are no proper landscape descriptions in these poems, but natural imagery occurs within certain lines. An example is the 'Elegy for Cú Roi mac Dáir' which opens with the movement of the tide. The translators note that the second half of the second line below 'employs two words spelt differently but almost identical in pronunciation, as if to suggest that the water and advances and retreats an equal distance, as it would at high or low water':
Dy ffynhawn lydan dylleinw aches,
dydaw, dyhebcyr, dybris, dybrys.
From sea's wide spring out flows the tide:
It advances, retreats, it smashes, crushes.
The most appealing poem in the book is 'Taliesin's Sweetnesses', a catalogue of the bard's favourite aspects of creation that reminded me of those lists you find in Sei Shōnagon's Pillow Book, such as her 'Things that make your heart beat fast'. Taliesin's list covers everything from jewellery and mead to 'a cleric in church if he's faithful,' but I've extracted below some things he enjoys in nature. When you put these together - berries, leaks, purple heather, ospreys on the shore, cattle on a sea marsh - you can start to picture the landscape of Wales and western Scotland that a real Taliesin would have known
Sweet are the berries at harvest time;
Sweet, also is wheat on the stem.
Sweet is the sun on clouds in the sky;
Sweet, too, is light on the evening's brow.
Sweet is a thick-maned stallion in a herd;
Sweet, too is the warp of a spider's web.
Sweet are ospreys on shore at high tide;
Sweet too is watching the seagulls play.
Sweet is the garden when leeks are thriving;
Sweet also, is field mustard sprouting.
Sweet is heather when it blossoms purple;
Sweet, too, is a sea marsh for cattle.
Sweet are the fish in the shining lake;
Sweet, too, is water's play of light and dark.