The speaker is traveling through a landscape—by car, then by train—and keeps seeing flowers pass too quickly to name. There is a wish to get out and walk back along the track to see what they really were. All the speaker can do is list what they were not: not fireweed, not bluebells, not lupine. That guessing creates a wistful, slightly frustrated mood, as if the answer is just out of reach. But the poem then opens into a quieter thought: maybe a glimpse can brush across the mind and be lost, and that loss is part of its value. Heaven, the speaker suggests, gives its brief sights only to those who cannot look too closely. The final feeling is both longing and acceptance—beauty noticed at the edge of vision, then allowed to remain mysterious.
A Passing Glimpse — Summary
I often see flowers from a passing car That are gone before I can tell what they are.
I want to get out of the train and go back To see what they were beside the track.
I name all the flowers I am sure they weren’t: Not fireweed loving where woods have burnt--
Not blue bells gracing a tunnel mouth-- Not lupine living on sand and drouth.
Was something brushed across my mind That no one on earth will ever find?
Heaven gives its glimpses only to those Not in position to look too close.