STRUCTURE AND AFFINITIES OF ATHROTAXITES BERRYI BELL,AN EARLY CRETACEOUS CONIFER

Compressions and impressions of leafy twigs, pollen cones, and seed cones of Athrotaxites berryi are abundant in certain layers of the Kootenai Formation (Aptian) in Montana and the Lower Blairmore Formation in adjacent Alberta. The twigs are densely covered by helically arranged leaves that are about 2 mm long and wide. Pollen cones are borne laterally on ultimate branch segments. Some are sessile, while others terminate a minute lateral branch. The cones are 3–4 mm in diam and about 10 mm long. Each sporophyll has a stalk that is about 0.7 mm long and an upturned laminar tip that is 1–1.5 mm long by 1 mm wide. At least two pollen sacs are attached to the abaxial side of each sporophyll. Seed cones are borne terminally on lateral branches that are often curved. These cones are about 10 mm at their widest diameter and about 15 mm long. Each bract and associated ovuliferous scale are fused to form a wedge-shaped complex that is 4–5 mm long. The complex is 0.7 mm wide at its base and expands to about 2.5 mm wide and thick near its apex. The tip of the complex narrows abruptly to a point and terminates in a spine that is about 0.5 mm long. At least one seed occurs on the adaxial side of each complex. Athrotaxites berryi belongs to the Taxodiaceae. It resembles modern Athrotaxis cupressoides but differs from it in too many aspects to be included in the modern genus.     

A FERTILE AXIS OF TRILOBOXYLON ASHLANDICUM,A PROGYMNOSPERM FROM THE UPPER DEVONIAN OF NEW YORK

A partially petrified impression of Triloboxylon ashlandicum (Aneurophytales) is the first recognized fertile axis of the genus. Identification of the fertile axis rests on the similarity of its anatomy with that of previously described vegetative specimens. Fertile organs replace some vegetative branches along part of the main axis. Fertile organs are twice dichotomized in one plane and bear elongate sporangia arranged pinnately. Vegetative branches differ in that they bear the ultimate appendages of the plant helically. The latter organs dichotomize many times in one plane. Although similar in size and morphology to the ultimate appendages, the fertile organs are homologous by position and vascular supply to the vegetative branches which they replace. Sporangia of T. ashlandicum dehisce longitudinally and terminate in an apiculate tip. Spores are unknown. Fertile organs of T. ashlandicum resemble those of other Aneurophytales and support the earlier placement of Triloboxylon in the order on anatomical grounds. T. ashlandicum differs from other Aneurophytales, however, by bearing vegetative organs at the distal end of its fertile axis.     

FERTILE CONIFEROPHYTE REMAINS FROM THE LATE TRIASSIC DEEP RIVER BASIN,NORTH CAROLINA

Seed cones (Compsostrobus neotericus gen. et sp. nov.), pollen cones, and vegetative remains of coniferophytes occur in Upper Triassic rocks of the Deep River Basin (Pekin Formation) of Central North Carolina. Seed cones have spatulate ovuliferous scales, each with two ovules and subtended by an elongated bract with an attenuate tip. Cuticle of seed cones resembles that of leaves on vegetative axes. Slender leaves are borne along two sides of the axis. Pollen cones have helically arranged microsporophylls, each with two abaxial sporangia bearing pollen grains of the Alisporites type. Seed cones, pollen cones, and vegetative remains suggest a coniferophyte very modern in aspect.     

Reconstruction of the Jurassic conifer Sewardiodendron laxum (Taxodiaceae)

Compressed seed cones and pollen cones of Sewardiodendron laxum are described from the Middle Jurassic of Yima, Henan, central China. They are either organically attached to or associated with leafy shoots. Seed cones are terminally borne. Each cone is ovate to elongated, up to 6.5 cm long and 3.5 cm wide, and consists of a stout axis and numerous helically arranged bract-scale complexes. The bract protrudes beyond and is partially fused with the reduced ovuliferous scale. The ovuliferous scale bears approximately six inverted, small, and flattened seeds. Pollen cones are borne in terminal clusters. Microsporophylls are helically arranged, each bearing three abaxial, basally fused pollen sacs. Pollen is assaccate, rounded, and with an inconspicuous pore. Morphological, structural, and cuticular features of seed cones, pollen cones, and leafy shoots of S. laxum are compared with those of fossil and extant conifers. S. laxum is included in Taxodiaceae and believed to have its closest affinities with a Mesozoic conifer Elatides and a group of Cunninghamia-like conifers. It is reconstructed as a half-evergreen tree that lived in a humid, warm-temperate climate.     

Reproductive biology of the endangered cypress Calocedrus macrolepis

We studied the reproductive biology of the endangered species Calocedrus macrolepis. We examined flower phenology and morphology, spatial distribution of male and female cones, pollen viability, variation in pollen density around the crown, and the pollination process. Calocedrus macrolepis is monoecious with unisexual flowers on the same branches. Pollen‐shed from male cones occurred from early September to mid‐February, whereas the female cones were receptive from mid‐September to mid‐March. The inconsistency of flowering periods between male and female cones within populations and among individuals extended the pollination period. There was a layered distribution pattern of male and female cones in the crown, with more male cones in the lower layer and more female cones in the upper layer. This resulted in different selfing and outcrossing rates at various locations. The pollen of C. macrolepis lack airbags, and consequently, it was dispersed within only 10 m of the mother tree. The short pollen dispersal distance could restrict gene flow among different geographical populations. Calocedrus macrolepis is endangered because of its high degree of selfing and inbreeding resulting from its monoecious characteristics and the short distance of pollen spread. These factors may result in a population decline.     

A NEW STRUCTURALLY PRESERVED PENNSYLVANIAN CORDAITEAN POLLEN ORGAN

Permineralized specimens of the pollen organ Gothania (Hirmer) consist of a primary axis bearing pollen cones in the axils of bracts that are four ranked. The bilaterally symmetrical primary axis consists of a uniform parenchymatous pith surrounded by up to 15 endarch-mesarch axile bundles. The cortex is two-parted and consists of an inner zone of subepidermal fibers. Bract traces arise from the ends of the ellipsoid stele. Traces to the cones are derived from the open ends of the stele, and at higher levels form a centrarch-medullated vascular system. Each pollen cone is constructed of up to 25 helically arranged scales, each vascularized by a single trace that may dichotomize. Scales are elongate and broad, and histologically composed of mesophyll parenchyma and fibrous layers. Stomata are restricted to the adaxial surface between rows of fibers. Up to 10 distal scales may be fertile, each with 4 elongate pollen sacs at the tip. Large monosaccate grains of the Felixipollenites-type are densely packed in each pollen sac. The well-preserved specimens of Gothania provide an opportunity to compare this genus with pollen cones assigned to the genus Cordaianthus, and to relate isolated plant organs to the Cordaitales.     

MORE EVIDENCE FOR CONIFER DIVERSITY IN THE UPPER TRIASSIC OF NORTH CAROLINA

An ovulate strobilus from the Upper Triassic Deep River Basin, North Carolina, has helically arranged, loosely aggregated, elongated, spatulate bracts with axillary ovule-bearing appendages with about 8–10 ovules attached in two lateral rows, with outwardly directed micropyles. The axillary ovuliferous appendage is homologous with the voltzialean fertile dwarf shoot, but probably not directly evolved from it. More credible is a suggested origin from a completely fertile axillary appendage such as that of the Lower Permian Trichopitys. The occurrence of this cone, Metridiostrobus palissyaeoides, gen. and sp. nov., along with Compsostrobus neotericus and Voltzia andrewsii, reflects considerable diversity among conifer ovulate cones during the Upper Triassic.     

Structure and affinities of the petrified plants from the cretaceous of Northern Japan and Saghalien. XII.Obirastrobus gen. nov., petrified pinaceous cones from the Upper Cretaceous of Hokkaido

Two new species of pinaceous cones belonging toObirastrobus gen. nov. are described from the Upper Cretaceous of Hokkaido. Bract-scale complexes are arranged helically and each consists of a small bract and a large scale. The bract and scale are separated. The scale tapers distally and its apex does not become papery. The anatomy of the bracts, scales, and seeds shows a combination of features unique in the Pinaceae and resembling those of the extant genusKeteleeria and the extinct genusPseudoaraucaria. Consecutive number from the previous paper (Ohsawaet al., 1992). Supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture Nos. 63540545 and 02640533 to Makoto Nishida.     

A NEW TAXODIACEOUS SEED CONE FROM THE OLIGOCENE OF WASHINGTON

Cunninghamiostrobus goedertii is described as a new species based on permineralized seed cones from the Early Oligocene of Washington. The fossils come from the Makah Formation and were found on the northern shore of the Olympic Peninsula. The cone consists of numerous bract-scale complexes arranged helically around a central axis. Each bract-scale complex has a large bract bearing a small flap of tissue adaxially that represents the ovuliferous scale. Up to three seeds were produced on each complex. The vascular trace to the bract-scale complex diverges from the vascular cylinder of the cone axis as a concentric strand. This divides in the outer cortex of the axis to form a large collateral bract tract abaxially and a minute scale trace adaxially. The latter continues outward to supply the ovuliferous scale. The bract trace divides, forming many strands outward which occur in a row with transfusion tissue between them. Many resin canals also occur in the bract. The new cone combines features found in modern cones of Athrolaxis, Cunninghamia, and Taiwania but is most similar to Cunninghamiostrobus yubariensis from the Late Cretaceous of Japan.     

The structure of aquaporin-1 at 4.5-A resolution reveals short alpha-helices in the center of the monomer

Aquaporin-1 is a water channel found in mammalian red blood cells that is responsible for high water permeability of its membrane. Our electron crystallographic analysis of the three-dimensional structure of aquaporin-1 at 4.5-A resolution confirms the previous finding that each subunit consists of a right-handed bundle of six highly tilted transmembrane helices that surround a central X-shaped structure. In our new potential map, the rod-like densities for the transmembrane helices show helically arranged protrusions, indicating the positions of side chains. Thus, in addition to the six transmembrane helices, observation of helically arranged side-chain densities allowed the identification of two short alpha-helices representing the two branches of the central X-shaped structure that extend to the extracellular and cytoplasmic membrane surfaces. The other two branches are believed to be loops connecting the short alpha-helix to a neighboring transmembrane helix. A pore found close to the center of the aquaporin-1 monomer is suggested to be the course of water flow with implications for the water selectivity.     

Pinus MUTOI (Pinaceae), a new species of permineralized seed cone from the upper Cretaceous of Hokkaido,Japan

Pinus mutoi is described as a new species on the basis of a permineralized seed cone from the Upper Cretaceous of Hokkaido, Japan. The cone is at least 20 cm long and up to 6 cm in diameter, consisting of a cone axis and numerous cone-scale complexes that are arranged helically around the axis. Two winged seeds are borne on the adaxial surface of each ovuliferous scale. Each complex receives a single trace from the vascular cylinder of the cone axis. In the scale base, all the resin canals occur abaxially to the vascular strand. The spatulate bract of the fossil is unique to the specimen among the cones of both living and fossil Pinus. The central umbo, broad sclerotic cortex of cone axis, and absence of serotinous features of the fossil cone suggest affinity with the subsection Sylvestres of the section Pinus, subgenus Pinus. This is the first record of permineralized preserved Pinus cone from the Cretaceous of Eastern Eurasia.     

Clevelandodendron ohioensis,gen. et sp. nov., a slender upright lycopsid from the late Devonian Cleveland Shale of Ohio

Clevelandodendron ohioensis Chitaley & Pigg gen. et sp. nov. is an almost entire lycopsid plant known from a single compressed specimen from the Cleveland Shale member of the Upper Devonian Ohio Shale. This unique specimen is 125 cm long, consisting of an unbranched, slender, monopodial axis with a partially preserved plant base bearing thick appendages at one end, and a compact, terminal ovoid bisporangiate strobilus at the other. The stem is 2 cm wide for most of its length. Visible on the decorticated stem surface are helically arranged, elongate leaf traces and laterally compressed, slender leaves along the stem margin. The plant base bears 4-6 thick appendages. The terminal strobilus is compact, ovoid, 9 cm long and up to 6 cm wide, morphologically similar to those of some Lepidodendrales, and bears helically arranged sporophyll/sporangium complexes with narrow bases and distal laminae up to 18 mm long, turned upward. Megaspores are 320-360 μm, trilete and laevigate, lacking a gula; microspores are 30-42 μm, trilete, indistinctly punctate and possibly assignable to Calamospora or Punctatisporites. Clevelandodendron demonstrates that slender unbranched lycopsids with an isoetalean plant habit similar to the Carboniferous genera Chaloneria and Sporangiostrobus and Triassic Pleuromeia-like forms were present as early as the Late Devonian. The early occurrence of this unique habit suggests that diversification within the isoetalean clade sensu Rothwell and Erwin (including both Isoetales and Lepidodendrales) was well established prior to the Carboniferous.     

Relationship between volatile compounds of Picea likiangensis var. linzhiensis cone and host selection of Dioryctria abietella

This study aimed to determine the relationship between volatile compounds of Picea likiangensis var. linzhiensis cone and host selection of Dioryctria abietella. During the infestation of P. likiangensis var. linzhiensis by D. abietella, their cones and branches emitted volatile compounds, which were extracted using CH₂Cl₂ extraction and XAD₂ adsorption methods, and were analyzed using gas chromatography–mass spectrometry. Before and after overwintering, D. abietella larva preferred annually infested cones and their extracts, and adult D. abietella preferred to lay eggs on annually infested cones and healthy cones of the year, and the oviposition rate of adult D. abietella was 72% on branches with healthy cones of the year, and no egg was laid on branches with annually healthy cones or branches without cones. The volatile compounds after infestation, α- and β-pinene, were significantly higher in cones than those in other tissues; however, myrcene in cones was significantly lower than those in other tissues. The annually infested cones produced β-caryophyllene and (1S)-(-)-β-pinene, while the annually healthy cones and branches produced myrcene and 3-carene. The annually infested cones and their extracts attracted D. abietella larvae, while that of healthy cones and annually infested cones attracted the adults, indicating that the terpene compounds: α-pinene, β-pinene, (1S)-(-)-β-pinene, limonene, and β-caryophyllene are attractive to D. abietella, and the terpene compounds—myrcene and 3-carene—from the branch tissues may be repulsive to D. abietella.     

Study of the Histology of Leafy Axes and Male Cones of Glenrosa carentonensis sp. nov. (Cenomanian Flints of Charente-Maritime,France) Using Synchrotron Microtomography Linked with Palaeoecology

We report exceptionally well-preserved plant remains ascribed to the extinct conifer Glenrosa J. Watson et H.L. Fisher emend. V. Srinivasan inside silica-rich nodules from the Cenomanian of the Font-de-Benon quarry, Charente-Maritime, western France. Remains are preserved in three dimensions and mainly consist of fragmented leafy axes. Pollen cones of this conifer are for the first time reported and in some cases remain connected to leafy stems. Histology of Glenrosa has not previously been observed; here, most of internal tissues and cells are well-preserved and allow us to describe a new species, Glenrosa carentonensis sp. nov., using propagation phase-contrast X-ray synchrotron microtomography, a non-destructive technique. Leafy axes consist of characteristic helically arranged leaves bearing stomatal crypts. Glenrosa carentonensis sp. nov. differs from the other described species in developing a phyllotaxy 8/21, claw-shaped leaves, a thicker cuticle, a higher number of papillae and stomata per crypt. Pollen cones consist of peltate, helically arranged microsporophylls, each of them bearing 6–7 pollen sacs. The new high resolution tomographic approach tested here allows virtual palaeohistology on plants included inside a dense rock to be made. Most tissues of Glenrosa carentonensis sp. nov. are described. Lithological and palaeontological data combined with xerophytic features of Glenrosa carentonensis sp. nov. suggest that this conifer has been adapted to survive in harsh and instable environments such as coastal area exposed to hot, dry conditions.     

Performance of the fir coneworm Dioryctria abietivorella (Grote) as affected by host species and presence or absence of seed cones

1 Larval performance of Dioryctria abietivorella (Grote) (Lepidoptera: Pyralidae) was compared when insects were reared in white spruce, black spruce and Jack pine seed orchards. For each species, half of the insects developed in the presence of cones, while the other half was maintained on branches without cones. 2 Significantly faster development rates were observed on spruce species when compared to Jack pine. Significant differences in survival were also recorded between the different feeding treatments. 3 The presence of seed cones on spruce species significantly increased insect mean weight compared with branches without cones, but no significant differences were noticed between the different tree species with cones. 4 White spruce is the most suitable host tree for fir coneworm feeding and the availability of seed cones plays an important role in determining D. abietivorella larval performance.     

A NEW SCIADOPITYACEOUS SEED CONE FROM THE UPPER CRETACEOUS OF HOKKAIDO,JAPAN

A sciadopityaceous seed cone, Sciadopityostrobus kerae, gen. et sp. nov., is described on the basis of a permineralized specimen from the Upper Cretaceous (Cenomanian–Coniacian) of Hokkaido, Japan. The peel method was applied for anatomical observations. The seed cone consists of a cone axis receiving numerous cone scale complexes that are arranged helically. Each complex generally has five inverted ovules that are oriented adaxially. The cone is similar to those of living Sciadopitys verticillata with respect to its peltate cone scale complex, with free apices of both bract and ovuliferous scale, trichomes on the bract, and a trifurcated ovuliferous scale strand. In the fossil, the bract and ovuliferous scale strands fuse with each other in the basal part of the cone scale complex, while S. verticillata bract and ovuliferous scale strands are derived separately from the vascular cylinder and remain separate throughout their length. The present specimen is one of the oldest records of structurally preserved cones that can be assigned to the family Sciadopityaceae.     

ACTINOXYLON BANKSII GEN. ET SP. NOV.: A PROGYMNOSPERM FROM THE MIDDLE DEVONIAN OF NEW YORK

A new genus from a Middle Devonian locality near Cairo, N. Y., is described. Actinoxylon gen. nov. is based upon pyritic petrifactions. Three orders of branching are present: penultimate branch, ultimate branch, and leaf. The penultimate branch bears spirally arranged ultimate branches and leaves, the leaves apparently replacing the branches in the spiral. The ultimate branches bear opposite to subopposite and decussate leaves. The leaves are non-planated, unwebbed structures which show at least three dichotomies. Each segment of the leaf is terete as are all other axes. Internally the penultimate branch has a six-lobed actinostele with mesarch protoxylem areas, one or two per lobe. Secondary xylem is visible in the oldest parts of several specimens. The xylem has helical-reticulate, reticulate, scalariform and circular-pitted elements. The presumptive areas of phloem are occupied by cells with dark contents. The cortex is composed of a parenchymatous inner region and a sclerenchymatous outer region. The ultimate branch traces are at first three-lobed protosteles, later becoming four-lobed. Several ultimate branch traces also possess secondary xylem while within the cortex of the penultimate branch. The leaf traces are terete strands. Below each forking of a leaf segment there is a corresponding forking of the vascular strand. Actinoxylon is compared with the progymnosperms Actinopodium, Svalbardia, Archaeopteris, Siderella, and Tetraxylopteris. The anatomy of the penultimate branch of Actinoxylon is similar to that of Actinopodium, Archaeopteris macilenta, and Siderella. The ultimate branch traces of Archaeopteris and Actinoxylon are similar. The ultimate branch stele and pattern of trace formation in Actinoxylon is similar to the stelar configuration and trace formation in the r + 2 axes of Tetraxylopteris schmidtii. The unwebbed leaves are similar to those of Archaeopteris fissilis, Svalbardia, and the terminal units of the Aneurophytales.     

ATTACHED LEAVES,INFLORESCENCES, AND FRUITS OF FAGOPSIS,AN EXTINCT GENUS OF FAGACEOUS AFFINITY FROM THE OLIGOCENE FLORISSANT FLORA OF COLORADO,U.S.A.

Specimens showing staminate and pistillate inflorescences attached to branches bearing Fagopsis longifolia (Lesq.) Hollick foliage, from the Oligocene Florissant flora of Colorado, permit a relatively complete characterization of the extinct Fagopsis plant. The alternately arranged simple leaves have pinnate craspedodromous venation and prominent simple teeth. Staminate inflorescences are globose on a stout peduncle and contain anthers with tricolporate pollen. Pistillate inflorescences are ovoid heads with compact, helically arranged three-flower units and are interpreted to have three styles per flower. The infructescence consists of small wedge-shaped cupules, each containing three tiny fruits, and subtended by a persistent bract. The cupules unravel from the swollen peduncle at maturity and are often dispersed as strings of adhering fruit-wedges which frequently take on a regular, more or less circular appearance. Fagopsis is unlike any living genus but has characters which support a relationship to the Fagaceae. Unlike extant members of the family, which typically have fruits adapted for animal dispersal, Fagopsis is less obviously specialized and perhaps adapted for wind dispersal. The striking differences in fruiting structures between Fagopsis and extant Fagaceae parallel the differences between the extant genera Platycarya and Juglans in the Juglandaceae, and Alnus and Corylus in the Betulaceae.     

Yuhania: a unique angiosperm from the Middle Jurassic of Inner Mongolia,China

Despite increasing claims of pre-Cretaceous angiosperms, whether there really are angiosperms in the Jurassic is apparently still an open question for many people before further evidence is available. This question can only be answered by studying more Jurassic plant fossils. Here we report a fossil angiosperm, Yuhania daohugouensis gen. et sp. nov, from the Middle Jurassic of Inner Mongolia, China. The plant includes connected stem, leaves, flowers, aggregate fruits, fruitlets, and seeds within fruitlets. The leaves are helically arranged along the curving stem, linear in shape, with 5–6 parallel veins. The aggregate fruit is pedicellate, composed of over 20 carpels/fruitlets helically arranged. Each fruitlet encloses a seed. The reproductive organs in various stages are found in the same plant, allowing us to understand the development of Yuhania. The occurrence of Yuhania in the Middle Jurassic re-confirms the Jurassic history for angiosperms that has been suggested by other independent research and adds to the on-going study on the early evolution of angiosperms.     

A new anatomically preserved ginkgoalean genus from the Upper Cretaceous (Cenomanian) of the Czech Republic

A new genus of ginkgoalean woody branch, Pecínovicladus kvaceki gen. et sp. nov., is described from the Upper Cretaceous (mid to late Cenomanian) Peruc-Korycany Formation at Pecínov Quarry, near Prague, Czech Republic. Eighteen branch specimens, anatomically preserved as charcoal, the product of wildfire, occur as allochthonous assemblages in intertidal facies and as parauthochthonous assemblages in supratidal salt marsh facies. Primary branches range from 7–13 mm in diameter, and are composed of a central, parenchymatous pith, a medial pycnoxylic xylem layer, and an outer periderm layer. Closely spaced, helically arranged leaf bases and rare secondary branch scars characterize the exterior. The branches are confidently referred to the Ginkgoales on the basis of a variety of diagnostic xylem features, most notably the presence of inflated axial parenchyma containing moulds of crystals, and by the precise anatomical correspondence of the leaf bases to those of detached, but facies-associated Nehvizdya obtusa leaves of known ginkgoalean affinity. The newly described ginkgoalean, together with cheirolepidiaceous conifers, formed fire-prone vegetation in halophytic salt marsh environments under a seasonal, subtropical climate.