PERIASTRON RETICULATUM UNGER AND AEROCORTEX KENTUCKIENSIS,N. GEN. ET SP., FROM THE NEW ALBANY SHALE OF KENTUCKY

Segments of anatomically preserved axes of the Lower Mississippian genus, Periastron, are analyzed in detail, and new features of histology and the pattern of vascular bundles are described. The name P. perforatum is shown to be a synonym of P. reticulatum. Division and fusion of vascular bundles in the axis result in variation in both their number (5–10) and form (in transverse section, from circular to elongate). In none of the 13 specimens studied is there any evidence of traces to lateral appendages, providing, with other evidence, support for the position that Periastron represents the petiole of a large leaf. Aerocortex kentuckiensis, a new name, is established for two specimens that resemble Periastron but which differ from it in being characterized by 2–4 vascular bundles in contrast to the 5–10 (or 11?) of Periastron, and by having centrally, rather than peripherally, located secretory ducts. Aerocortex and Periastron might represent, respectively, proximal and distal regions of a petiole.     

BOSTONIA PERPLEXA GEN. ET SP. NOV., A CALAMOPITYAN AXIS FROM THE NEW ALBANY SHALE OF KENTUCKY

Bostonia perplexa, gen. et sp. nov., was collected from the Lower Mississippian Falling Run member of the Sanderson Formation. The single short segment of an axis, preserved as a petrifaction, contains at least three vascular columns, each with both primary and secondary tissues. Primary xylem is two or three ribbed, and contains several mesarch protoxylem strands. Gymnospermous secondary xylem is characterized by both uniseriate and multiseriate rays. The ground tissue is parenchymatous except for a few clusters of sclerotic cells. In its apparent polystelic nature, the specimen superficially resembles members of the Pennsylvanian to Permian Medullosaceae. All evidence currently available, however, leads to the conclusion that this species should be placed in the Upper Devonian to Lower Mississippian Calamopityaceae. It has not been determined with certainty whether the species is polystelic (in the sense of the Medullosaceae), or whether the apparent polystely is the result of stelar branching proximal to the level of branch divergence.     

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.     

A WOODY LYCOPSID STEM FROM THE NEW ALBANY SHALE (LOWER MISSISSIPPIAN) OF KENTUCKY

A lycopsid axis from the New Albany Shale (Sanderson Formation) of Kentucky is described. The stem, which branches dichotomously, is 45 mm in diameter and is characterized by a relatively narrow parenchymatized protostele, a 3.0 mm-thick cylinder of secondary xylem, a tripartite cortex, and a periderm that is more than 5.0 mm thick. The secondary xylem is composed of uniseriate and biseriate vascular rays and narrow tracheids with scalariform wall thickenings on both radial and tangential walls. The periderm is characterized by elongate, thick-walled cells, some of which broaden tangentially in the outer part of the tissue forming zones that appear wedge-shaped in cross section. Surface features of the axis, including leaf bases, are not preserved. The stem is tentatively regarded as a member of the Lepidodendrales in accordance with the numerous anatomical characters that it shares with more recent representatives of the order. Because the external morphology is not known, however, the possibility exists that the axis corresponds to a protolepidodendralean taxon currently known only from compression and/or impression remains or some other nonlepidodendralean plant that produced secondary xylem. The extremely narrow profile of the secondary xylem tracheids (relative to other arborescent lycopsids) is interpreted as evidence that the plants grew in a habitat that was substantially drier than the Upper Carboniferous coal swamps.     

PETRIFIED PLANTS FROM THE UPPER MISSISSIPPIAN OF NORTH AMERICA. I: THE SEED RHYNCHOSPERMA GEN. N.

Petrified seeds of Upper Mississippian age (Chester Series) are described from sediments from northwestern Arkansas. Specimens of Rhynchosperma quinnii gen. et sp. n. are radially symmetrical and range in length from 1.2 to 2.2 cm and 1.0 to 1.3 cm at the greatest diameter. The seeds are ovate with a tapered apex having 8–10 integumentary ribs and a broadly rounded chalaza. The integument is two-parted, consisting of an outer presumably soft tissue with secretory canals and an inner layer constructed of longitudinally oriented thick-walled cells. Nucellus and integument are confluent, but they diverge near the seed midlevel with the free portion of the nucellus forming a dome-shaped pollen-receiving structure. Additional features such as vasculature and the structure of well-preserved megagametophytes are described. The petrified specimens are compared with taxa instituted for casts and impressions which include Rhynchogonium and Boroviczia. The ovulate versus cupulate nature of these genera which has remained uncertain until now appears to be settled in favor of an ovular identity.     

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.     

辽宁西部早三叠世苏铁植物一新属--Mediocycas gen. nov.及其演化意义

报道苏铁植物大孢子叶化石一新属———中间苏铁属(Mediocycasgen.nov.)。标本采集于辽宁省西部,喀左县杨树沟煤矿后山的早三叠世红砬组。这些标本以前曾被处理为疑问化石(Problematicum)。因当时资料不足,所以没有确定属种名称。但鉴于这些化石在苏铁类早期起源与演化研究中具有重要意义,故对它们作了重新研究。文中除了以喀左中间苏铁(Mediocycaskazuoensisgen.etsp.nov.)为典型种进行描述以外,还对新属、种在苏铁类起源与演化方面的意义作了较为详细的讨论。     

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.     

中国西北地区菊科新植物

多年生草本。茎直立,圆柱形,密被白色向上贴生的长毛,微左右曲折,先端分枝。基生叶和茎下部叶未见,茎中部和上部叶卵形,宽椭圆形或倒卵状披针形,长2-8厘米,宽1-4厘米,先端钝尖或近圆形,基部渐狭,缘有不明显的波状圆齿,齿端有脐服体,表面绿色,被白色短硬毛,背面被灰白色浓密的贴生长毛,叶脉在背面凸起,有3-4对侧脉,叶柄短或近无,有狭翅。     

MORPHOLOGY OF MARSILEA VESTITA. III. MORPHOGENESIS OF THE LEAVES OF ETIOLATED PLANTS

The laminae of etiolated Marsilea vestita leaves develop by means of marginal meristems. Unlike light-grown plants, the form of the etiolated plant is not affected by growth on a solid medium. All of the young leaves isolated from light-grown submerged plants will elongate in darkness. The smallest, etiolated, uncoiled leaves develop into land leaves when they are placed in light, and this development occurs regardless of whether the leaves remain on the plant or are isolated on nutrient agar. Only these smallest leaves (2.3 mm average length) are actually capable of being converted from a submerged leaf form to a land leaf form by darkness.     

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.     

CHARLIEA MANZANITANA,N. GEN., N. SP., AND OTHER ENIGMATIC PARALLEL-VEINED FOLIAR FORMS FROM THE UPPER PENNSYLVANIAN OF NEW MEXICO AND TEXAS

Charliea is a new genus (type-species: C. manzanitana), based on pinnately compound leaf material from the richly fossiliferous Virgilian (Upper Pennsylvanian) shales of the Kinney Brick Company quarry near Albuquerque, New Mexico. In several features Charliea resembles Russellites or a zamioid cycad. It has linear-oblong pinnae with broad, oblique attachment and a truncate tip, which is deeply incised to form two to four nearly equal lobes. The venation is simple, parallel, and sparingly dichotomous, each vein ending at the distal margin. The Kinney beds also contain Plagiozamites planchardi, another zamioid form with parallel-veined pinnae, differing from Charliea chiefly in having rounded tips and veins ending in the denticulate margins. An unnamed third form (genus B) in the Kinney beds has long, narrow pinnae with parallel veins and blunt tips; this strongly resembles the Mesozoic conifer Podozamites, but may just as well represent a cycadophyte. Another unnamed taxon (genus A), from an Upper Pennsylvanian deposit in Jack County, Texas, resembles genus B or Russellites in general shape and venation, but the critical distal margins are unknown. In their single-ordered parallel venation, these four foliar types contrast sharply with the two-ordered pinnate venation of most Pennsylvanian fern-like leaves, and seem to foreshadow Mesozoic morphologies. This tendency toward precocious evolution of parallel-veined foliar form in North America is also expressed by a single occurrence of the Asiatic, Permian genus Tingia in the Lower Pennsylvanian of Utah, and by the presence of the predominantly Triassic cycadeoid genus Pterophyllum in the Lower Permian of Texas.     

盘菌纲一新属——新齿裂菌属

在安徽省黄山杜鹃［Ｒｈｏｄｏｄｅｎｄｒｏｎｍａｃｕｌｉｆｅｒｕｍ　Ｆｒａｎｃｈ．ｓｓｐ．ａｎｈｗｅｉｅｎｓｅ（Ｗｉｌｓ．）Ｃｈａｍｂ.］上发现盘菌纲一新属──新齿裂菌属（ＮｅｏｃｏｃｃｏｍｙｃｅｓＹ．RＬｉｎ,Ｃ．Ｔ．Ｘｉａｎｇ＆Ｚ．Ｚ．Ｌｉ）。对该属及其模式种──杜鹃新齿裂茵（ＮｒｈｏｄｏｄｅｎｄｒｉＹ．ＲＬｉｎ,Ｃ．Ｔ．Ｘｉａｎｇ＆Ｚ．Ｚ　Ｌｉ）进行了描述和讨论。主模式标本存放在安徽农业大学森林保护教研室（ＡＡＵＦＰ）．     

盘菌纲一新属──新齿裂菌属

在安徽省黄山杜鹃［Ｒｈｏｄｏｄｅｎｄｒｏｎｍａｃｕｌｉｆｅｒｕｍ　Ｆｒａｎｃｈ．ｓｓｐ．ａｎｈｗｅｉｅｎｓｅ（Ｗｉｌｓ．）Ｃｈａｍｂ.］上发现盘菌纲一新属──新齿裂菌属（ＮｅｏｃｏｃｃｏｍｙｃｅｓＹ．RＬｉｎ,Ｃ．Ｔ．Ｘｉａｎｇ＆Ｚ．Ｚ．Ｌｉ）。对该属及其模式种──杜鹃新齿裂茵（ＮｒｈｏｄｏｄｅｎｄｒｉＹ．ＲＬｉｎ,Ｃ．Ｔ．Ｘｉａｎｇ＆Ｚ．Ｚ　Ｌｉ）进行了描述和讨论。主模式标本存放在安徽农业大学森林保护教研室（ＡＡＵＦＰ）．     

ACAULANGIUM GEN. N., A FERTILE MARATTIALEAN FROM THE UPPER PENNSYLVANIAN OF ILLINOIS

Material described by Graham as Cyathotrachus bulbaceus is believed to represent a new genus that is a common constituent of Upper Pennsylvanian coal balls. The sessile synangia of Acaulangium gen. n. are borne in a row on either side of the pinnule midrib and are composed of four to six short, tapering, laterally appressed sporangia. The sporangia have extended tips which curve over the inside of the synangium distally and delimit a small open area inside the synangium. The outer facing walls of the sporangia are two to three cells thick throughout while the inner facing walls are uniseriate. During dehiscence the sporangia separate laterally and spore release results from the rupture of a row of elongate cells along the inner sporangium midline. Among species of Scolecopteris the new genus resembles S. illinoensis and S. minor var. parvifolia but differs in its sessile synangial attachment. The additional parenchyma present between sporangial cavities in the synangia of Acaulangium, and the tendency toward bilateral symmetry suggests an early stage in the evolution of a bivalve synangium such as is present in Marattia.     

MUSOPSIS N. GEN.: A BANANA-LIKE LEAF GENUS FROM THE EARLY TERTIARY OF EASTERN NORTH GREENLAND

A fossil flora from the Late Paleocene-Early Eocene Thyra Ø Formation of eastern North Greenland (paleolatitude 77° N) has yielded monocotyledon leaf impressions with characters seen only in the closely related modem species in the families of Heliconiaceae, Musaceae, and Strelitziaceae. The combination of large costae widths and parallel, nonanastomosing, lateral veins that depart at right angles from the costae in the fossil material are features present only in leaves of extant species from these families. Three basic venation patterns also are recognized in the modem species of these families, but except for the genera Strelitzia and Phenakospermum, none of these patterns are present exclusively in any one family. Musopsis n. gen. is created for the fossil material from Greenland, but it is considered a form genus due to the lack of gross morphological features that can be used for separating leaves of the modem genera in Heliconiaceae, Musaceae, and Strelitiziaceae. It is the first known Arctic occurrence of fossil leaf material resembling this modem group of taxa.     

我国东部地区虎刺属新植物

本文报道我国东部地区茜草科虎刺属1新种、1新变种和1新记录,即浙江虎刺D.shanii K.Yao et M.B.Deng sp.nov.,浙皖虎刺D.subspinosus Hand.-Mazz.var.salicifolius M.B.Deng et K.Yao和短刺虎刺D.subspinosus Hand.-Mazz.。皖刺属隶属于茜草科,是亚洲东部的一个小属,约11种1亚种及1变种。我国分布于长江流域及其以南地区,常生于常绿阔叶林下。主要特征:花冠喉部被长柔毛,花或少花的聚伞花序腋生,花为4出数。有些种类是民间广泛应用的草药,有祛风止痛的功效。我们在整理我国东部地区植物区系资料的过程中,除了习见的虎刺D.indicus (L.)Gaertn.f.外,发现了1新种、1新变种及1新记录,现在本文发表。