Abstract:

Austrovideira dettmannae gen. & sp. nov. from the early Oligocene Capella Flora in central Queensland is the first fossil Vitaceae wood described from the Southern Hemisphere. A new combination, Stafylioxylon ramunculiformis (Poole & Wilkinson) Pace & Rozefelds for a Northern Hemisphere fossil wood is also proposed. Austrovideira and Stafylioxylon share with Vitaceoxylon secondary xylem with two diameter classes of vessels, wide vessels usually solitary, narrow vessels forming radial chains, very wide and tall rays, scanty paratracheal parenchyma and septate fibres. Austrovideira differs from Vitaceoxylon in having scalariform intervessel pits and homocellular rays composed exclusively of procumbent cells. This combination of features is seen in the Ampelocissus‐Vitis clade, and a clearly stratified phloem with fibre bands alternating with all other axial elements and phloem rays rapidly dilating towards the periderm is restricted to Parthenocissus and Vitis. Stafylioxylon shares with Austrovideira the presence of scalariform intervessel pits but it differs from that genus in both ray composition and bark anatomy, as it lacks a stratified phloem. These fossil wood genera demonstrate that the lianescent habit in the Vitaceae was established by the Eocene in the Northern Hemisphere and by the Oligocene in the Southern Hemisphere. The pollen and seed fossil record shows that the Vitaceae were in Australia by the Eocene and fossil seeds suggest that the family had radiated by this time. The Oligocene Capella flora with two seed taxa and fossil wood (Austrovideira) provides further evidence of an Australian radiation. The fossil evidence, suggests a significant Gondwanic history for the family.

Key words: Australia, Austrovideira, Cenozoic, Stafylioxylon, Vitaceae, wood and bark anatomy.