Precipice with overhanging grotto

Coach House Books have published a new edition of Christian Bök's Crystallography. Among its crystalline poems the book includes a 'Key to Speleological Formations', relating each letter of the alphabet and four punctuation marks to a specific landform. So, for example p is a 'precipice with overhanging grotto', l is 'an unbroken column of dolomite' and i is a 'plinth from broken stalagmite'. Strung together they can form a complete landscape, e.g.

p l i n i u s

precipice with overhanging grotto
an unbroken column of dolomite
plinth from broken stalagmite
archway of oolitic limestone
an unbroken column of dolomite
trench from alluvial riverbed
escarpment with avalanching scree

It seems a rather arid place, but as Bök has provided the key to a book of poems about crystals it is not really surprising that the landscape resembles a kind of quarry. A book of pastoral poems could define the letters quite differently, and p l i n i u s might then spell out an overhanging branch, a classical column, a fragrant flower, a gently sloping hill, another fragrant flower, a gently sloping valley and a winding stream...