Evidence of Pollen Tubes in Paleozoic Pteridosperms

See allHide authors and affiliations

Science  18 Feb 1972:
Vol. 175, Issue 4023, pp. 772-774
DOI: 10.1126/science.175.4023.772


A saccate pollen grain with a branched pollen tube has been discovered within the pollen chamber of a fossil seed-fern ovule of Middle Pennsylvanian age. This suggests that microgametophytes comparable to those of living gymnosperms were produced by some Paleozoic pteridosperms.