One Good Fern Deserves Another
From Biograffitti by John M. Burns. (Quadrangle, 1975)

Prothallia of ferns are always haploid
Producing sperms and eggs that seize the procreative role
When, of a dampness, they unite to form a diploid.

Up springs the frondly sporophyte,
with rhizome, root, and rachis
And a meristem that's apical and tight.
It uncoils; but on a leaf that is preparing for meiosis
Sporangia in clusters make a very sori sight.