Gnetales


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Related to Gnetales: gnetum, Ginkgoales

Gnetales

an order of GYMNOSPERMS whose members have true vessels in the secondary wood and an absence of archegonia in the ovule. In these features they resemble ANGIOSPERMS.
References in periodicals archive ?
Keywords: Chhidru Formation, Palynomorphs, Monocolpate, Sulcate, Gymnosperms, Peltasperms, Gnetales, Medullosales and Ephedralels.
Gnetales (Ephedra, Gentum, Welwitschia) is a distinct lineage among the six major groups of extant gymnosperms which has occupied various and contested positions in hypothesized seed plant phytogenies (Graham & lies, 2009; Mathews, 2009; Rydin and Korall, 2009).
Phylogeny of seed plants based on all three plant genomic compartments: extant gymnosperms are monophyletic and Gnetales are derived conifers.
Extant seed plants comprise five clades [ILLUSTRATION FOR FIGURE 1 OMITTED]: cycads, Ginkgo, conifers, angiosperms, and Gnetales (Ephedra, Welwitschia, Gnetum).
Structure and function of female and bisexual organ complexes in Gnetales.
What Brown most importantly recognized, albeit in a somewhat circumlocutious way, was that in cycads, conifers and Gnetales, among extant seed plants, the ovules receive pollen directly, whereas in flowering plants the ovule, being enclosed within a carpel, cannot receive pollen, that being the function of the stigma.
Rudall is doubtful that the monocot cambium is equivalent to secondary thickening meristematic activity in non-monocot angiosperms and Gnetales, and indeed, it is not.