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Angiosperm origins and relationships of major lineages. Vessels and tracheids. Companion cells. Pollen. columellae. Carpel and integuments. Fertilisation. Development of Fruits. Cycads. Conifers. Ginkgos. Gnetaceae. Bennettitales. Archaefructus. The oldest angiosperm.
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Pollen columellae
Early lineages (ii) Chloranthaceae Piperaceae
Earliest Angiosperms • Perennial • Evergreen • Woody • Vascular bundles in a ring, • Vessel-less wood • Alternate, simple, coriaceous leaves with entire or sparsely-toothed margins • Lacking stipules • Lacking ethereal oils
Earliest Flowers • Insect-pollinated • Radially symmetrical • Several - many tepals, spirally-arranged, free and distinct • Bisexual • Stamens poorly differentiated into anther and filament • Anthers with four microsporangia opening by longitudinal slits • Superior ovaries • Pollen monosulcate and often lacking well-developed columellae • Carpels fused by secretion, with an elongated stigma and a style poorly differentiated from ovary. • Placentation marginal
Dicotyledons Embryo with 2 cotyledons Primary root persistent Herbs, shrubs or trees Stele cylindrical Pollen tricolpate Monocotyledons Embryo with 1 cotyledon Primary root replaced by adventitious roots Mostly herbs Vascular bundles scattered Pollen monocolpate
Anomalous Dicots • Flowers in 3’s or with numerous parts • Poorly differentiated anthers • Poorly developed styles and elongate stigmas • Pollen monocolpate or inaperturate • Ethereal oils in vegetative parts
A summary of the major groups that occurred in greater than 50% of the 1000 jackknife replicates (from Soltis et al. 2000).
ANITA • Amborellaceae • Nymphaceae • Illiciaceae • Trimeniaceae • Austrobaileyaceae
MAGNOLIIDS • Chloranthaceae • Magnoliaceae • Annonaceae • Myristicaceae • Lauraceae • Piperaceae • Aristolochiaceae • Ceratophyllaceae
New Caledonia Amborellaceae
Amborella trichopoda • Shrubby • Lacks vessels • No ethereal oils • Radial flowers with 7-11 tepals • Dioecious • Ascidiate carpels
Nymphaceae Victoria amazonica