title: Stranded Arrangement of Sporopollenin in the Exine of Microspores of Poa annua.
abstract: In the early microspore wall of the grass Poa annua L., sporopollenin is arranged in bundles of anastomosing strands. Each bundle contains at least two strands, each about 50 A in diameter, which anastomose or intertwine and look like a meshwork with pores of the mesh up to 50 A in diameter. After the early microspore stage the exine becomes homogeneous; it is similar in this respect to the exines or ornamented parts of the exines of pollen of other angiosperms examined by electron microscopy.
authors.forename: J R
authors.initials: JR
authors.lastname: Rowley