|
|||||
|
|
Evidence of pollen tubes in paleozoic pteridosperms |
|
| Authors: | Rothwell G W |
| Abstract: | 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. |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ | |