TRILOBOXYLON ASHLANDICUM GEN. AND SP. N. FROM THE UPPER DEVONIAN OF NEW YORK

A new taxon is described from the Upper Devonian, Oneonta formation in the northern Cats-kills of New York. Triloboxylon gen. n. is represented by petrifactions showing two orders of branching. The main axis bears branches spirally and the latter bear the ultimate appendages spirally. Ultimate appendages branch dichotomously twice, in one plane. Primary xylem of the main axis and branches is three-armed with mesarch protoxylem extending in a continuous band within each arm. Primary xylem of the ultimate appendage is terete and dichotomizes twice. Metaxylem elements are characterized by scalariform and circular-bordered pitting on all walls. The cortex is composed entirely of isodiametrical parenchyma cells. Triloboxylon is compared with other genera with three-lobed protosteles. Its possible affinity with the Aneurophytales is shown. The morphological nature of the “frond” of the Aneurophytales and the possibility that the group possesses the morphological equivalent of simple leaves are discussed.     

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.     

ANATOMY AND RELATIONSHIPS OF SOME DEVONIAN PROGYMNOSPERMS FROM NEW YORK

New specimens of Triloboxylon ashlandicum Matten and Banks (1966) show additional features of the anatomy and morphology of the plant. The primary xylem has strands of parenchyma associated with trace formation. Secondary xylem and phloem are described for the first time. The outer cortex, previously unknown, contains hypodermal fiber strands. The ultimate appendages are much divided and planated. Specimens of Aneurophyton hallii (Arnold, 1940) were reexamined and newly prepared. They are transferred to the genus Triloboxylon as T. hallii. Triloboxylon is transferred from Pteropsida-Incertae Sedis to the Aneurophytales. New information on the morphology and anatomy of Telraxylopteris is presented and its identity to Sphenoxylon is supported.     

THE CAIRO FLORA (GIVETIAN) FROM EASTERN NEW YORK. I. REIMANNIA,TERETE AXES,AND CAIROA LAMANEKII GEN. ET SP. N.

A collection of over 200 petrified Middle Devonian plants was made from a single locality near Cairo, New York. This paper represents the second of a series enumerating the plants of the flora. Reimannia aldenense with a single lateral appendage containing a terete xylem strand that divides is present. Reimannia is thought to represent young branches within the Aneurophytales. Many of the sections made for the study of the flora contain small, terete axes. Some have a very distinctive epidermis. Some dichotomize several times. Cairoa lamanekii gen. et sp. n. shows closest affinity to the Aneurophytales yet differs in that the shape of the primary xylem is not consistently repeated from one order of axis to the next. It is suggested that Cairoa and Proteokalon represent a distinctive subgroup in the Aneurophytales.     

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.     

IBYKA AMPHIKOMA,GEN. ET SP. N., A NEW PROTOARTICULATE PRECURSOR FROM THE LATE MIDDLE DEVONIAN OF NEW YORK STATE

Ibyka gen. n. is described from late Middle Devonian compressions and petrifactions collected in eastern New York State. It is a robust plant of which three orders of branching and ultimate appendages (leaves) are known. The latter dichotomize up to five times, are arranged spirally on all orders of branching, are three-dimensional, and all orders are terete in cross section. Fertile appendages, homologous with the sterile, are terminated by sporangia. The protostele has five or six arms, the maturation is mesarch, and the protoxylem disintegrates leaving lacunae at the tips of the arms. Traces to appendages are terete and arise spirally from the tips of the arms. The primary xylem consists of tracheids only, the phloem of thin-walled cells and probable tanniniferous cells. The cortex consists of parenchyma and groups of sclereids. Secondary xylem is lacking. Ibyka is placed in a new order, Ibykales, close to the Hyeniales (protoarticulates) and to the Pseudosporochnales all three of which probably evolved from Trimerophytina.     

TETRAXYLOPTERIS SCHMIDTII: ITS FERTILE PARTS AND ITS RELATIONSHIPS WITHIN THE ANEUROPHYTALES

The fertile branching system of Tetraxylopteris is composed of successive “nodes” bearing opposite and decussately arranged, upcurved sporangial complexes. By means of the transfer technique the morphology of the sporangial complex was revealed. It consists of a main stalk which dichotomizes twice producing four major branches. Each of the four branches is further subdivided three times, the subdivisions being arranged alternately and pinnately. The ultimate divisions bear the sporangia singly and terminally. The sporangial complexes decrease in size distally and are more tightly curved at the apex. The sporangia are oblong-oval with an acute apex. The spores are identical to the dispersed spore taxon Rhabdosporites langii, Richardson. They are spherical, trilete and pseudosaccate with a fine granular ornament on the pseudosaccus. They are 75–176 μ in diameter and show developmental stages from young tetrads to separated, fully mature spores depending on the age of the sporangium from which they were obtained. This is the first account of spores in sporangia of Tetraxylopteris. The diagnosis of the genus and species are emended to include the new information and the order Aneurophytales is redefined.     

TRIPLOCHITIOXYLON (STERCULIACEAE): A NEW GENUS OF WOOD FROM THE EOCENE OF OREGON AND ITS BEARING ON XYLEM EVOLUTION IN THE EXTANT GENUS TRIPLOCHITON

A new sterculiaceous wood, Triplochitioxylon oregonensis gen. et sp. n., was collected from a Middle Eocene locality in the Clarno Formation of Oregon. Anatomical data indicate a close natural relationship between T. oregonensis and the living species of Triplochiton, a genus endemic to tropical Africa. The fossil is believed to represent a population of the group or complex from which Triplochiton evolved. The basic differences in the xylem organizations of the two genera are explained by a significant reduction of fusiform initial length and by a complete suppression of post-cambial parenchyma strand elongation in the extant genus. Paleobotanical and biogeographical evidence suggest that the xylem evolution has been strongly influenced by the increasing aridity of the African continent.     

STENOKOLEOS BIFIDUS SP. N. IN THE UPPER DEVONIAN OF NEW YORK STATE

Stenokoleos is a genus for petrified axes from the Mississippian New Albany Shale to which an Upper Devonian occurrence in New York is added. Two orders of branching were known and the plant was thought to be related to coenopterid ferns. The new petrified axes from New York reveal three orders of branching. A pair of rachides emerges from one side of the stem at each node. Their position alternates at successive nodes (distichous). Each rachis bears alternately arranged pinnae. The shape of the xylem strand and the number of protoxylem areas are variable. Traces to the pairs of rachides arise either as two separate strands or as a single strand that is presumed to divide while still within the cortex of the stem. Traces to pinnae are ellipsoid or clepsydroid. Tracheids are scalariform and uni- or biseriate, circular-bordered pitted. Peripheral loops are present in all orders of branches. Protoxylem strands are numerous and maturation is mesarch. Cortex is parenchymatous where it is preserved but outer cortex is missing. Stenokoleos and Reimanniopsis are placed in a new family, Stenokoleaceae. This is classified as Incertae Sedis among Pterophytina in Tracheophyta. It is suggested that the plant is related more closely to the Mississippian pteridosperms Tristichia and Tetrastichia than to the coenopterid ferns.     

OSMUNDA WEHRII,A NEW SPECIES BASED ON PETRIFIED RHIZOMES FROM THE MIOCENE OF WASHINGTON

Silicified rhizomes from Miocene strata near Yakima, Washington represent a new species of Osmunda. The stems are 8–13 mm in diameter and are surrounded by a thick sheath of adherent leaf bases, each of which shows stipular expansions typical of the Osmundaceae. The new species has an ectophloic siphonostele in which the xylem cylinder is dissected by leaf gaps with 12–14 strands being visible in a given stem cross section. Such sections also show 12–16 leaf traces in the cortex. The xylem of each leaf trace diverges from the xylem cylinder of the stem as an adaxially concave strand with its protoxylem organized into a single medial adaxial cluster. Initial bifurcation of the leaf-trace protexylem occurs as the leaf trace passes through the outer cortex of the stem. In the basal part of the stipular region of the petiole base, thick-walled fibers form an arch on the abaxial side of the sclerenchyma ring around the petiolar bundle. This arch persists throughout most of the length of the stipular region, with the thick-walled fibers becoming reorganized into two lateral masses in the distal part of the stipular region. Similar thick-walled fibers form an elongate strip of tissue in each wing of the stipule along with several small clusters scattered near the sclerenchyma ring. The new species belongs to the subgenus Osmunda and shows that during the Neogene, the latter existed as a group of closely related species much as it does today. Furthermore, Osmunda wehrii combines features of the modern O. regalis, O. japonica, and O. lancea with those of O. claytoniana and thus supports the inclusion of the latter species in the subgenus Osmunda.     

SVALBARDIA BANKSII SP. NOV. FROM THE UPPER DEVONIAN (FRASNIAN) OF NEW YORK STATE

Svalbardia banksii sp. nov., is described from the Upper Devonian (Frasnian) Fish Cabin Creek locality near Pond Eddy, New York. The compression consists of ultimate branches bearing spirally arranged, unwebbed leaves. The unwebbed leaves are up to 3.2 cm long, are somewhat flexuous, and dichotomize in more than one plane. The new species is similar to the reconstruction of Actinoxylon banksii from the Middle Devonian (Givetian) of New York and strengthens the supposed relationship between Svalbardia polymorpha and Actinopodium nathorstii from Mimerdalen, Spitzbergen.     

EQUISETUM CLARNOI,A NEW SPECIES BASED ON PETRIFACTIONS FROM THE EOCENE OF OREGON

Equisetum clarnoi is described from four silicified stem fragments and numerous small roots from the Eocene Clarno Chert of Jefferson County, Oregon. Stems are up to 8.0 mm in diam and have sunken stomata arranged vertically in a single line flanking each of the external biangulate stem ridges, features that clearly ally this species with the subgenus Hippochaete. External stem ridges are equal in number to the carinal hypodermal bands. The hypodermis is composed of fibers and has prominent carinal bands up to 0.75 mm long and shorter vallecular bands. Cortical parenchyma cells enclose prominent vallecular canals which are lined by specialized thick-walled parenchyma cells. The double, common endodermis has prominent casparian strips. Vascular bundles are composed of four to seven metaxylem tracheids flanking each side of the phloem and protoxylem tracheids which occur singly on the internal surface of the small carinal canals. Leaf sheaths in cross section have an adaxial fibrous layer and an external or near external fibrous bundle. Roots are up to 2.0 mm in diam and have paired cuboidal epidermal cells from which root hairs arise. The stele of the root is central and shows exarch primary xylem maturation. Equisetum clarnoi most closely resembles the extant Equisetum hyemale var. affine.     

STUDIES OF NEW ALBANY SHALE PLANTS. I. STENOKOLEOS SIMPLEX COMB. NOV.

Beck , Charles B. (U. Michigan, Ann Arbor.) Studies of New Albany shale plants. I. Stenokoleos simplex comb, nov. Amer. Jour. Bot. 47(2): 115—124. Illus. 1960.–A specimen of Stenokoleos from the Falling Run member of the Sanderson formation is described and shown to belong to the same species as Mesoneuron simplex (Read and Campbell, 1939). Among the distinctive features of this species are traces of triangular shape bearing 3 mesarch protoxylem areas, metaxylem tracheids with scalariform pitting, and the presence of fibers in the outer phloem. The new specimen indicates that Stenokoleos had a basically cruciform xylem strand which gave rise to pairs of traces, each trace supplying one of a pair of lateral appendages which occurred on opposite sides of the main axis, but at different levels. The fern-like nature of Stenokoleos is emphasized and it is suggested that this genus most closely resembles members of the Zygopteridaceae.     

CRENATICAULIS,A NEW GENUS OF DEVONIAN PLANTS ALLIED TO ZOSTEROPHYLLUM,AND ITS BEARING ON THE CLASSIFICATION OF EARLY LAND PLANTS

The name Crenaticaulis verruculosus is proposed for slender, pseudomonopodially and dichoto-mously branching plants that bore opposite to subopposite sporangia along the stem and two rows of prominent, multicellular teeth on opposite sides of the terete axis. Epidermal cells were either narrow and elongate parallel to the stem or short with a papillate outer tangential wall. Axillary tubercles were present on one side of the stem near lateral branches. Some tubercles bore remnants of branches. Sporangia dehisced along their distal margins into two unequal halves. No spores were found. Occasional short lengths of stem were petrified by iron pyrite. Sections revealed a cortex consisting of four to six rows of thick-walled cells and a xylem strand. The strand was elliptical in transverse section and maturation was exarch. Tracheids were chiefly scalariform. It is suggested that the so-called axillary tubercles, known in several plants of Devonian age, were scars of rhizophores like those in the modern genus Selaginella. The plant is referred to the subdivision Zosterophyllophytina.     

THE LEPIDOPHYTIC AFFINITIES OF THE GENUS CHINLEA AND OSMUNDITES WALKERI

Chinlea campii Daugherty and Osmundites walkeri Daugherty are species of petrified stems from the Upper Triassic Chinle Formation of Arizona that were described as members of the fern family Osmundaceae. Investigation of additional material indicates that the two species are conspecific and belong to the Lepidophyta. The stems are radially symmetric and have an ectophloic siphonostele in which the xylem cylinder is thick and deeply furrowed. Internal pressure against the xylem cylinder caused by the lateral expansion of the pith in some stems produces what appears in transverse section to be a ring of up to 60 separate xylem strands. Leaf traces are small, terete, collateral and have exarch xylem. They are arranged in a tight spiral. Adventitious roots, secondary xylem, and secondary cortex are lacking. The stems are classified under the binomial Chinlea campii, and other axes that have similar cortical anatomy but in which all vascular tissues have decayed are treated as Chinlea sp. Both types of stems are interpreted as ephemeral aerial shoots of an herbaceous plant. Of the known fossil Lepidophyta, Chinlea is most similar to Pleuromeia and Nathorstiana, but it differs from each of these genera in a number of respects and is therefore included in Lepidophyta incertae sedis.     

THE MORPHOLOGY OF STIGMARIA STELLATA

Stigmaria stellata Goeppert is a lycopod underground system occurring in Upper Mississippian and equivalent age rocks of Europe and North America. This taxon has previously been based on impressions exhibiting radiating ridges and furrows around each lateral appendage scar and numerous polyhedral projections on the remainder of the axis. Anatomically preserved specimens from the Chester Series (Upper Mississippian) of Illinois reveal that the distinctive surface pattern of this species results from polyhedral wedges of thick-walled cells in the outer cortex. Decortication produces a smooth outer surface that is indistinguishable from that of the much more abundant Stigmaria ficoides. The structure of S. stellata is quite similar to the structure of other petrified stigmarians, but the following are some of the anatomical characters that distinguish it: (1) presence of abundant polyhedral wedges of thick-walled cells in the outer cortex; (2) absence of secondary cortex; (3) very tall rays associated with appendage traces that remain confluent with the secondary xylem to its outer margin; (4) the absence of a connective in the lateral appendages. The anatomical characters of Stigmaria stellata confirm it as a taxon of at least specific rank.     

VASCULAR CONNECTION BETWEEN LATERAL ROOTS AND STEM IN THE OPHIOGLOSSACEAE

The vascular connection between lateral roots and stem in the Ophioglossaceae and in two leptosporangiate fern species was examined. Two types of connections were found: “gradual” connections, which resemble leaf traces in ontogeny and morphology, and “abrupt” connections, which resemble the connections between lateral roots and their parent roots. Gradual root-stem connections occur in the genera Ophioglossum and Helminthostachys and in Woodwardia virginica. They are initiated in shoot apices distal to the level where cauline xylem elements mature. They resemble leaf traces in being provascular (procambial) strands that connect the cauline stele with the future vasculature of lateral appendages. As with leaf traces, gradual connections are part of the provascular and, later, protoxylem continuity between stems and lateral appendages. Gradual connections have many features in common with leaf traces, and the term root trace is applicable to them. The order of radial maturation of the primary xylem in gradual connections varies in different parts of the connections. It is endarch near the intersection with the cauline stele and exarch where the connections intersect root steles. Gradual connections resemble the transition regions of certain seed plants where protoxylem is also continuous from stem to root and the order of maturation is found to change continuously from stem to root. Abrupt connections occur in Botrychium and Osmunda cinnamomea. They develop in shoot apices at levels where cauline xylem is mature or maturing. The mature xylem does not dedifferentiate, so provascular and protoxylem continuity of the kind found in root traces does not occur. Also, reorientation of the order of maturation does not occur in abrupt connections. Xylem connectors are found in the region where radially oriented elements of the connections abut the longitudinally oriented cauline elements. Abrupt connections resemble the connection of secondary roots with their parent root systems since xylem connectors and the lack of continuity are also features found in these vascular systems. The resemblance of the vascular pattern of the fern root trace to the transition region of seed plants suggests that the radicle is more closely comparable to the cladogenous roots of pteridophytes than hitherto supposed.     

PITYOSTROBUS PUBESCENS,A NEW SPECIES OF PINACEOUS CONES FROM THE LATE CRETACEOUS OF NEW JERSEY

This new species is based on a single semifusinized cone from the Late Cretaceous (Cenomanian) of New Jersey. The cone is flattened but essentially complete. It is 55 mm long and 8 by 13 mm in diam. Scale apices are thin, rounded, and entire, lacking evidence of an umbo or spine. The vascular cylinder of the cone axis is organized as a series of separate strands. The scale is made up of a basal portion that stands out nearly perpendicular to the cone axis and a sharply upturned distal portion. The bract base has a pronounced abaxial keel. Bract and scale traces diverge from the vascular cylinder of the cone axis separately from one another. A poorly developed interseminal ridge is present at the chalazal end of the seeds. An unusual feature of the cone is the presence of a trichome-bearing epidermis on the cone axis, bract-scale complex, and near the scale apex. Resin canals diverge into the bract-scale complex abaxial to the scale trace with branches becoming adaxial to the scale trace outward. A number of features of the new species occur in cones of Abies, Cedrus, Keteleeria, Larix, Picea, Pseudolarix, Pseudotsuga, and Tsuga as well as in the extinct genus Pseudoaraucaria. Features of Pinus are absent. This suggests that Pseudoaraucaria may have served as an ancestral source for modern genera other than Pinus with Pityostrobus pubescens representing an evolutionary intermediate.     

PERTICA,A NEW GENUS OF DEVONIAN PLANTS FROM NORTHERN MAINE

A new genus of Devonian age fossil plants is described from the Trout Valley Formation of northern Maine. Abundant compression material permits a rather complete understanding of its morphology. Pertica quadrifaria Kasper and Andrews, gen. et sp. nov., was an erect plant, perhaps a meter tall, with a pseudomonopodial main axis and dichotomous side branches. The side branches were arranged in a clockwise spiral (from base to apex) and were tetrastichous. They dichotomized numerous times, with the intervals between dichotomies decreasing distally. The ultimate branchlets bore numerous sporangia in dense clusters. Other side branches were completely sterile. Pertica quadrifaria is classified in the Subdivision Trimerophytina of Banks. Its evolutionary significance rests in the fact that it is a link in the chain of increasingly complex early vascular land plants.