Immense polygons of evening

Sometimes one wonderful line makes me fall in love with a poem. I offer the following -- in which the title first draws me in and then "immense polygons of evening" delights me even more.  Here, by Paula Closson Buck, is "A Betrayal of Integers," which uses mathematical terminology as the perfect mix of seasonings for a gourmet dish. 

A Betrayal of Integers     by Paula Closson Buck

                                                                 Cumberland Island, Georgia

We have counted ninety egrets swooning
                    into the trees behind the mansion
where the Carnegies used to hang
                              their white towels.  Birds, towels:
intelligible sums, like oranges and oranges.
                                        Subtract from them the sea

                                        and the sea turtle transmogrified
on the strand.  The buzzards' code has settled to a pine tonight
though the blue dark is still
                                        as distant as the cold
that entered a room on a woman's shawl.

When she walked among the peregrine fronds,
                                                                   and seed ticks
found the pale inversions of her knees,
                              from where did she return
to disturb the immense
                         polygons of evening, opening a line, trailing
bits of wet
                 leaf across an oriental rug?

Poet / Professor Paula Closson Buck is a member of the English Department of Bucknell University and Editor of West Branch.  "A Betrayal of Integers" is found in Buck's collection, The Acquiescent Villa (Louisiana State University Press. 1998).