David Winship Taylor

Vessel-bearing stems of ASOVINEA TIANIIgen. et sp. nov. (Gigantopteridales) from theUpper Permian of Guizhou Province, China.

Permineralized gigantopterid stems of Vasovinea tianii Li et Taylor gen. et sp. nov. were collected from the Upper Permian of Guizhou Province, China. They are slender and bear prickles, trichomes, and compound hooks. Internally, the stems have a sparganum cortex, eustele, and secondary xylem. The mesarch protoxylem tracheids have annular to helical thickenings, and metaxylem tracheary elements have scalariform and/or transversely elongated, bordered pits, while those of the secondary xylem have scalariform to circular bordered pits. Importantly, the inner part of the secondary xylem has large vessel elements with foraminate-like perforation plates. The hooks and other morphological and anatomical characteristics are similar to those found in gigantopterids, suggesting that Vasovinea is a member of the Gigantopteridales. The vegetative plant is reconstructed from permineralized stems and Gigantopteris-type leaves based on the anatomical similarities and intimate association. The eustele, secondary xylem, and other features support the placement of the order among the seed plants. Ecologically, Vasovinea is suggested to have been a vine or liana that used compound hooks to climb among the trees in a Permian tropical rain forest. The occurrence of vessels could have been an efficient adaptation to allow the slender stems to conduct sufficient water to the large Gigantopteris-type leaves.

Aculeovinea yunguiensis Gen. et Sp. Nov. (Gigantopteridales), a New Taxon of Gigantopterid Stem from the Upper Permian of Guizhou Province, China1

Permineralized gigantopterid stems of Aculeovinea yunguiensis Li et Taylor gen. et sp. nov. were collected from the Upper Permian of western Guizhou, China, and prepared with the cellulose acetate peel technique. The stems are narrow and covered with prickles, and contain a parenchymatous cortex with sparganum‐type fibrous strands, an endodermis‐like layer, variable amounts of secondary xylem, a eustele of mesarch primary vascular bundles, and a parenchymatous pith. The stems are vesselless, and tracheids of the protoxylem have annular, helical, scalariform, or reticulate thickenings, while the metaxylem tracheids have scalariform to transversely elongated bordered pits. The secondary xylem has nearly storied tracheids with bordered pits that are commonly multiseriate, alternately arranged, and more or less transversely elongated but are occasionally uniseriate scalariform. Heteroseriate rays and scattered axial parenchyma in single‐celled columns also are found in the wood. From a different site of western Guizhou, a compressed axis comparable to the permineralized stems was found connected to a pair of Gigantonoclea blades. This connection and anatomical similarities between the co‐preserved permineralized stems and permineralized Gigantonoclea leaves allow for a reconstruction of the plant. Aculeovinea yunguiensis is a unique seed plant, and its slender stems and large leaves indicate that it had a vine‐liana habit and had grown in the Permian tropical rain forests.

Scutifolium jordanicum gen. et sp. nov. (Cabombaceae), an aquatic fossil plant from the Lower Cretaceous of Jordan, and the relationships of related leaf fossils to living genera.

A new species of aquatic plant, Scutifolium jordanicum gen. et sp. nov., Taylor, Brenner & Basha, is described from the Albian of Jordan. The leaves are microphyllous with a symmetrical, elliptical to suborbiculate shape, convex to rounded apex and base, and actinodromous to palinactinodromous primary venation. The peltate, centrally attached petioles are narrow, elongate, and alternately arranged on similarly sized stems. The leaves appear to be thick and have aerenchyma. Comparisons to plants with centrally peltate leaves and palmate venation and to aquatic plants with floating leaves suggest that S. jordanicum belongs to the Cabombaceae lineage within the Nymphaeales. Cladistic analysis including the fossil and living members of the Nymphaeales shows that the S. jordanicum is basal to the living members of the family and has unique characters not found in any living genera. This is the oldest evidence of the Cabombaceae from the Old World. Inclusion of two other Early Cretaceous peltate leaf fossils in the phylogenetic analysis indicates their affinities to Cabombaceae and that some of the shared derived characters for the living members are progressively acquired in the fossils. These data show the Cabombaceae were widespread in Gondwana and Laurasia by the mid-Cretaceous.

The Origin and Evolution of the Angiosperm Carpel

The angiosperm carpel is one of the defining characteristics of flowering plants. Carpels are unique to angiosperms and are found in all of its members. Yet, due to the distinctive structure and function of carpels, deducing homologies among carpels and other seed-plant organs has been difficult. Progress in understanding carpel homologies and evolution is being made in a number of directions. Homologies, as well as transformations between them, have been proposed among angiosperms and other seed plants. These include homologies among the reproductive structures of Glossopterids, Caytonia, and other fossil taxa (e.g., Thomas, 1925, Thomas, 1957; Andrews, 1963; Stebbins, 1974; Doyle, 1978; Retallack and Dilcher, 1981a; Crane, 1985; Doyle and Donoghue, 1986b). Recent studies have examined the homologies and transformations among female reproductive organs through outgroup comparison (e.g., Crane, 1985; Doyle and Donoghue, 1986b; Taylor, 1991a) and interpretations of carpel structure within angiosperms (Taylor, 1991a). Developmental, morphogenic, and genetic studies have also provided additional insight on carpel structure and development (e.g., Szymkowiak and Sussex, 1992; Gasser and Robinson-Beers, 1993; Modrusan et al., 1994). Together, data from these diverse sources are leading to a revised view of carpel homology and structure.

Nonlethal assay system of β-glucuronidase activity in transgenic tobacco roots

Previously, assay conditions for the GUS enzyme have required lethal and/or destructive conditions which do not allow for the continued observation of living plants. The replacement of sodium phosphate buffer with potassium phosphate buffer and the removal of potassium ferrocyanide and EDTA resulted in an assay for the GUS enzyme that is both nondestructive and nonlethal to tobacco plants and therefore allows observations of tobacco roots through time.

Floristics and Paleoecology of an Early Cretaceous Flora from Jordan

Abstract Abundant plant fossils were recovered from Albian fluvial and back-swamp sediments of the Jarash Formation (Kurnub Group) of Jordan. The flora consists of angiosperms, ferns and gymnosperms. Water lily Scutifolium jordanicum, marsilealean fern Marsileaceaephyllum mahisensis and tree fern Weichselia reticulata are from a thin crevasse splay layer of a small fluvial system. Four species of other ferns, Phlebopteris hickeyi sp. nov., Piazopteris branneri, Aspidistes beckeri and Cladophlebis sp., and two gymnosperms, Zamites hoheneggeri and Brachyphyllum mamillare, are from a back-swamp dark gray carbonaceous lens. Phlebopteris hickeyi represents a new fern species that has five preserved pinnae with unique characteristics, including small sori and sporangia. The relatively small pinnules with massive midveins and grooves along either side of midveins represent a unique combination of characters. The water lily S. jordanicum and marsilealean fern M. mahisensis may have grown in ponds, lakes or slow-moving streams along the margin of the back-swamps. However, the tree fern W. reticulata is thought to have grown in tropical coastal areas. The co-occurrence of W. reticulata with S. jordanicum and M. mahisensis indicates that the habitat of water lily and marsilealean fern was not far from the coast. Additionally, M. mahisensis suggests the presence of dry seasons because extant Marsileaceae need a dry terrestrial phase for reproduction, which is consistent with climate implied from the xerophilic characters of W. reticulata. The matoniaceous fern Phlebopteris hickeyi, Piazopteris branneri, A. beckeri and bennettitalean Z. hoheneggeri were probably growing in the back-swamps. However, the conifer B. mamillare probably grew in coastal areas close to the back-swamps.

Phylogenetic Analysis of Fossil Water Lilies Based on Leaf Architecture and Vegetative Characters: Testing Phylogenetic Hypotheses from Molecular Studies

Abstract Understanding the phylogenetic diversification of the water lilies (Nymphaeales sensu lato) in deep time is currently on the rise through studies based on both molecular analyses and the fossil record. An enhanced data set of leaf architectural and vegetative characters, for example, was found to be in broad agreement with phylogenies based only on molecular characters. Yet questions remain open regarding the relationships among the genera and subgenera of Nymphaea, the minimum time of divergence of familial and subfamilial clades and the phylogenetic radiation of the nymphaeoids during the Cenozoic that led to the living genera. Here we build on the aforementioned enhanced data set by adding a suite of nine, new or previously studied, Early to Late Cretaceous and Cenozoic fossil leaves to elucidate the phylogenetic positions of the fossil taxa, to test hypotheses based on molecular studies and to resolve phylogenetic relationships within Nymphaeales. In our phylogenetic analysis, five fossil leaf species show strong relationships with Nymphaeaceae and weaker subfamilial relationships to Nymphaea subgenus Lotos and to the Victoria—Euryale clade. Three fossil leaf species have strong relationships to Cabombaceae and are stem taxa. Taken as a whole, these new phylogenetic analyses yield strong evidence for the monophyly of the living families and some subfamilial clades. They also provide support for a divergence of Cabombaceae and Nymphaeceae by the Early Cretaceous. Finally, they suggest that some subfamilial clades of Nymphaeaceae may have originated by the Albian—Cenomanian, at the time of rapid diversification of the early angiosperms.

The Multi-Stranded Career of Leo J. Hickey

1 National Museum of Natural History, Smithsonian Institution, Washington, DC 20013 USA 2 Department of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798 USA 3 Harvard University Botanical Museum, 26 Oxford Street, Cambridge, MA 02138 USA 4 Corresponding author: Department of Biology, Indiana University Southeast, 4201 Grant Line Road, New Albany, IN 47150 USA —email: dwtaylo2@ius.edu