Moonlight pollination in the gymnosperm Ephedra (Gnetales).

Pollen and Pollination in Ephedra (gnetales)

Development of sterile ovules on bisexual cones of Gnetum gnemon (Gnetaceae).

Angiosperms and Gnetales (Ephedra, Gnetum, Welwitschia) represent the only seed plants that regularly produce bisexual cones. Unfortunately, the fertility and function of ovules formed on bisexual cones of Gnetales have remained unclear. Some reports indicate that the ovules are sterile while others indicate that they may develop into seeds. This study demonstrates three different developmental...

Application of proteomics to the study of pollination drops1

UNLABELLED PREMISE OF THE STUDY Pollination drops are a formative component in gymnosperm pollen-ovule interactions. Proteomics offers a direct method for the discovery of proteins associated with this early stage of sexual reproduction. • METHODS Pollination drops were sampled from eight gymnosperm species: Chamaecyparis lawsoniana (Port Orford cedar), Ephedra monosperma, Ginkgo biloba, J...

Former diversity of Ephedra (Gnetales): evidence from Early Cretaceous seeds from Portugal and North America.

BACKGROUND AND AIMS The extant species of the seed plant group Gnetales (Ephedra, Gnetum and Welwitschia) have been considered a remnant of a much greater, now extinct, diversity due to the pronounced differences in form and ecology among the genera. Until recently, this hypothesis has not been supported by evidence from the fossil record. This paper adds to the expanding information on Gnetale...

Did insect pollination cause increased seed plant diversity?

The dominant paradigm for the disproportionate number of flowering plants is the unique coevolution that they underwent with pollinating insects. The theory underlying this biotic pollination hypothesis contradicts more generally accepted evolutionary theory. Furthermore, various lines of empirical evidence falsify the biotic pollination hypothesis: (a) several lineages of plants were insect po...