Individual Sporangia Research Articles

A new species of Botryopteridium Doweld from the early Permian Wuda Tuff Flora and its evolutionary significance

A botryopterid plant is described based on five anatomically preserved fronds from the early Permian Wuda Tuff Flora. Fronds are tripinnate with oval to triangular pinnules. Fertile pinnae concentrate proximally on the frond, while vegetative pinnae mainly occur distally, but occasionally position proximally as the first ultimate pinna of the penultimate fertile pinnae. Fertile pinnules are strongly involute and enclose the reproductive organs. Fertile organs comprise six to ten sporangia grouped in a sorus with a receptacle. Individual sporangia are stalked and have a proximal horizontal biseriate annulus. In situ spores are trilete, triangular to circular, with baculate sculptures. Anatomically, the foliar trace is rake-like, with up to eight median xylary ridges composed of mixed metaxylem and protoxylem tracheids. The specimens are established as a new species of Botryopteridium Doweld, a substituted name for Botryopteris Renault due to its later homonym with Botryopteris Presl. Botryopteridium sinensis sp. nov. displays a combination of features that were previously known individually from different species within Botryopteridium. Although information on its stem morphology is unknown, the new species is suggested to be a small tree-fern living in the forest understory. Moreover, the new plant shows a strong resemblance to late Paleozoic catenalean ferns including Rastropteris, Skaaripteris, and several basal osmundalean genera, thus providing an evolutionary link between members of the first and second evolutionary radiation of Paleozoic ferns.

Serological estimation of the level of cross-fertilization in the monoecious liverwort Pellia epiphylla n = 9

Using protein antigens as markers, antigenic differentiation of progenies obtained from individual sporangia was examined. The experiments were expected to permit estimation of cross-fertilization frequency in the monoecious liverwort species, <em>Pellia epiphylla</em>, n = 9. The results obtained indicated segregation into two serological types, i.e. pointed to cross-fertilization, in approximately, 80% progenies. In correlation with electrophoretic studies, employing two peroxidase alleles and two shikimic acid dehydrogenase alleles as markers, the result made possible the establishment of cross-fertilization frequency at approximately 93% The data may indicate an absence of self-fertilization in this liverwort species and, thus, self-incompatibility. This may be included among the facors responsible for maintenance of genetic variability in populations of this species, in which haplophase is the prevalent phase of its life-cycle.

Feeding Activities of Slugs on Myxomycetes and Macrofungi

molds have two stages that may develop into a large enough mass to serve as a potential food source for animals. The plasmodium is a soft, flattened sheet of acellular protoplasm capable of migrating, feeding, and growing up to several meters in length along the surface of decaying logs and leaf litter. Under ideal conditions fruiting bodies that develop from the plasmodial stage may form a single cushion shaped aethalium up to 74 cm across or thousands of individual sporangia less than 1 mm in diameter that may

Permineralized Marattiales from the Stephanian and Autunian of central France: a reinvestigation of Grandeuryella renaultii (Stur) Weiss emend

A reinvestigation of specimens initially described by Renault (1883) as fertile Pecopteris oreopteridia and distinguished as Grand'Eurya renaulti Stur (1883) and Grandeuryella renaulti Weiss (1885), is presented. The species diagnosis is amplified to features of pinnule size and morphology, venation, and morphology of synangia, individual sporangia and spores. A lectotype is chosen from silicified specimens from Grand-Croix, France (Stephanian). The description of the genus Grandeuryella Weiss is emended for bilaterally symmetrical synangia borne on heavily vascularized receptacles along the lateral veins of highly recurved pecopterid pinnules; sporangia exannulate, united before dehiscence, free to receptacle afterwards, producing monolete spores. The taxonomic position of the species and of the genus is discussed and it is concluded that the validity of mode of attachment and fusion of sporangia as generic characters must be evaluated taxon by taxon. Grandeuryella is regarded as distinct from Eoangiopteris and Millaya, and possibly the equivalent of the compression genus Danaeites. Grandeuryella is compared to sections of extant Angiopteris. Those features that differ from Angiopteris are shared with other Paleozoic Marattiales and presumably represent synplesiomorphies.

Comatricha Anomala, A New Record for the Western Hemisphere

warts interspersed with a few isolated patches of reticulum. This ornamentation was beautifully illustrated by Rammeloo (1975) prior to the formal description of the taxon. The collection to be reported on here was made on decayed wood, Lower Bidwell Park, Chico, Butte Co., California, on March 23, 1967 by Dwayne H. Curtis (collection number 657). It has been deposited in the Herbarium of the University of California (UC). Since C. anomala has never been described in English and since the California material differs somewhat from the Belgian material, a detailed description of Curtis's collection is given below. Sporangia (FIG. 1) in small, loose clusters of 10-40, stalked, 0.5-1.5 mm high, sporangium proper ovoid to, more commonly, cylindric, rounded at the base and apex, 0.4-1.25 mm tall and 0.4-0.6 mm diam, bright rusty brown. Hypothallus thin, membranous, shiny, colorless, connecting the individual sporangia of each cluster. Stipe short, approximately one-fourth the total height, ridged, angular or flattened, opaque, shiny, dark reddish brown to, more commonly, black. Peridium predominantly evanescent, but persisting, especially near the apex, in small, irregular, bright rusty brown, iridescent patches. Columella a continuation of the stipe, tapering upward and continuing nearly to the sporangial summit where it merges with the capillitium, sinuose at the tip, colored as the stipe. Capillitium abundant, arising evenly along the entire length of the columella, bright reddish brown, the threads slender, distinctly, but irregularly flattened, lacking large membranous expansions, branching 2-4 times, rarely anastomosing to form a loose, wide-meshed network with numerous short, pointed, free ends, the larger threads bearing sparsely scattered tubercles 1-2 ,um diam. Spores (FIG. 2) bright rusty brown in mass, pale brown by transmitted light, globose, 8.0-9.0 Am diam, minutely but densely warted and bearing 2-5 reticulate areas per spore, these reticulate areas 2.0-2.5 Am diam. Plasmodium unknown. The C. anomala collection from California dif-

The Fine Structure of the Pre-Meiotic Stages of Sporogenesis in Onoclea sensibilis

Ultrastructural features of the dividing meiocyte of Onoclea sensibilis L. were described by the author (1977), and those of the young spores arising from this cell by Marengo and Badalamente (1978). Since a light microscopic study of this species by the author (1949) showed an apparent decrease in size of cytoplasmic inclusions from the sporangium initial to the spore mother cell, it is of interest to elucidate these changes on the ultrastructural level. Individual sporangia dissected from young fertile fronds were routinely fixed in glutaraldehyde followed by osmium tetroxide and embedded in Epon (Spurr, 1969). Sections 0.5um thick were cut from individual sporangia and were examined by phase contrast microscopy without staining. From sporangia identified as containing pre-meiotic stages in sporogenesis, thin sections were cut with a diamond knife, stained with uranyl acetate and lead citrate, and examined with an Hitachi HU11A electron microscope. The sporangial initials (Fig. 1) appear to contain large, osmiophilic bodies (Fig. 1, t) which resemble closely the tannin accumulations described by Ledbetter and Porter (1970). The appearance of vacuoles (v) within these bodies is followed by their disappearance in the later stages of sporogenesis, including newly formed spores. Mitochondria (m) appear hardly larger than those in later stages and in newly formed spores. Their internal structure, however, differs from that of mitochondria in newly formed spores. Cristae appear not to be shelf-like, but rather mitochondrial material separated by internal cavities. This peculiar and distinctive internal structure persists through at least the early prophase of meiosis (Fig. 6,m), following which their cristae extend as plates, continuous across the mitochondrion (Marengo, 1977). The osmiophilic bodies are still present in early sporogenous cells (Fig. 2,t), with an occasional vacuole apparently replacing the tannin mass (Fig. 2, v). By the time the sporogenous cells approach the rounded-up meiocyte stage, the osmiophilic bodies have disappeared and lipid droplets appear in the cytoplasm (Fig. 3,L). In the dividing sporogenous cell in anaphase (Fig. 4), the mitochondria appear concentrated in the polar regions of the spindle. The distribution of mitochondria at mitotic anaphase appears to contrast markedly with that of the meiotic anaphase I, where the mitochondria are concentrated at the edge of the spindle preparatory to invading it, and form the mitochondrial plate characteristic of interphase following the first division as well as all phases of the second meiotic division (Marengo, 1949, 1977). In the early prophase of the first meiotic division (Fig. 5), spore mother cell polarity is reflected in a concentration of mitochondria at the base of a barely

BOTRYOPTERIS PINNULES WITH ABAXIAL SPORANGIA

Small sporangia borne abaxially on pinnules attached to Botryopteris foliar members are described from coal ball petrifactions of Early Pennsylvanian age. This is the first report of laminar sporangia in this genus. Sporangia are stalked and borne singly near lateral veins on Sphenopteris‐like pinnules. Individual sporangia are of the leptosporangiate type, with a lateral annulus and a dehiscence zone of thin‐walled cells immediately adjacent to the annulus. Spores are small, trilete, triangular in outline, typically have blunt spines covering the exine, and correspond to the dispersed spore genera Acanthotriletes, Leiotriletes, or Lophotriletes. These sporangia and their spores are unlike previously described globose Botryopteris fructifications from the Middle and Upper Pennsylvanian, but are similar to sporangia produced by modern members of the Osmundaceae.

Doneggia complura gen. et sp. nov., a filicalean fern from the Upper Pennsylvanian of Ohio

The recent discovery of numerous permineralized frond segments in Upper Pennsylvanian sediments provides an opportunity to describe a new genus of the Sermayaceae and further enhance our knowledge of Paleozoic filicaleans. Specimens of Doneggia complura gen. et sp. nov. consist of up to three orders of biseriately branched frond segments with abaxial curvature of the vascular strand in proximal pinnae and large sori of superficially borne sporangia on laminar pinnules. Sori occur on pinnule lobes below vascular bundles and consist of about 25–35 sporangia. Individual sporangia are oblong, 0.6 mm long and 0.45 mm in maximum diameter, and are attached by a short stalk. As in Sermaya, the horizontal–oblique annulus consists of two rows of interfingering cells and is interrupted at one side by a narrow band of longitudinally oriented, thin-walled cells that presumably acts as a zone of dehiscence. Also, as in Sermaya, the vascular bundles have adaxially disposed protoxylem strands and crowded bordered pits on walls of the metaxylem tracheids. Spores are radial, trilete, triangular in polar view, and measure 45–63 μm in diameter. Material of this type helps demonstrate that some taxa that are currently assigned to the Coenopteridales actually represent vegetative organs of Paleozoic filicaleans.

The Fine Structure of the Newly Formed Spore of Onoclea sensibilis

The fine structure of the dividing meiocyte of Onoclea sensibilis L. was described by Marengo (1977), and that of the mature spore of the closely related Matteuccia struthiopteris (L.) Tod. by Marengo (1973). It is of interest to establish the ultrastructure of the cells formed at the termination of the second meiotic division. Marengo (1949) reported that cytoplasmic inclusions resolvable by light microscopy apparently disappeared during spore enlargement and that proplastids and plastids made their appearance as the large vacuole was replaced by more cytoplasm. To establish the identity of cytoplasmic inclusions received from the meiocyte and to elucidate the fine structure of the young spore, an electron microscope study was made of a sporangium shown by thick sections to contain young spores just separating from the tapetum (Fig. 1, T). Individual sporangia dissected from young fertile fronds were fixed in glutaraldehyde followed by osmium tetroxide and embedded in Epon (Spurr, 1969). 0.5 /um sections were cut from individual sporangia and examined by phase contrast microscopy without staining. From a sporangium identified as having spores at the desired stage, thin sections were cut with a diamond knife, stained with uranyl acetate and lead citrate, and examined with an Hitachi HU-11A EM. Identifiable inclusions present in the young spore shown in Figs. I and 2 include lipid droplets (L), amyloplasts (A), and mitochrondria (M). Small vacuoles (V) are present, as well as a loosely organized endoplasmic reticulum. At this stage, the spore nucleus appears to have not yet reached full interphase, since a nucleolus is not present and the nuclear membrane (Fig. 2, NM) is poorly defined. The mature spore of this species has a nucleolus occupying fully onethird of the nuclear cross-section (Marengo, 1956). It is hoped that the optical disappearance and re-appearance of inclusions in the enlarging spore can be followed with ultrastructural techniques. Properly buffered fixative may allow preservation of stages plasmolyzed by the fixatives of light microscopy. Older sporangia are to be dealt with in the next phase of this study.

SPORES OF BOTRYOPTERIS GLOBOSA AND BOTRYOPTERIS AMERICANA FROM THE PENNSYLVANIAN

A study of spores from fertile pinnae of Botryopteris from middle and upper Pennsylvanian coal balls from Iowa, Illinois, and Kansas indicates that there are two distinct species, Botryopteris globosa and B. americana. The organization and attachments of fertile pinnae and the sporangial morphology and dimorphism are identical in the two species. Data are given on fertile pinnae dimensions, attachments of six fertile pinnae, spore counts from individual sporangia, and spore morphology. The ornamentation of B. americana spores is verrucate to rugulate with verrucae fusing to a variable extent to form bars and convolute ridges; B. globosa spores are vermiculate or fossulate to densely rugulate with scattered verrucae. Comparisons are made with B. forensis and a re‐interpretation of the spore forms of B. forensis is suggested.

CALLANDRIUM CALLISTOPHYTOIDES, GEN. ET SP. NOV., THE PROBABLE POLLEN‐BEARING ORGAN OF THE SEED FERN, CALLISTOPHYTON

A new genus of pteridosperm pollen organ is described from Pennsylvanian age coal balls of Illinois. Individual sporangia are grouped into radial synangia which are borne in opposite pairs on the abaxial surface of slightly modified pinnules. Sporangia contain monosaccate pollen with a distinct sulcus, referable to the pollen genus Vesicaspora. Pinnules are borne on a regularly pinnate frond which is circinately coiled when young. At least a large portion of the frond is fertile and possesses anatomical features similar to those of Callistophyton. Phyletic relationships with other pteridosperm pollen organs are discussed.

Callandrium Callistophytoides, Gen. et sp. nov., The Probable Pollen- Bearing Organ of the Seed Fern, Callistophyton

A new genus of pteridosperm pollen organ is described from Pennsylvanian age coal balls of Illinois. Individual sporangia are grouped into radial synangia which are borne in opposite pairs on the abaxial surface of slightly modified pinnules. Sporangia contain monosaccate pollen with a distinct sulcus, referable to the pollen genus Vesicaspora. Pinnules are borne on a regularly pinnate frond which is circinately coiled when young. At least a large portion of the frond is fertile and possesses anatomical features similar to those of Callistophyton. Phyletic relationships with other pteridosperm pollen organs are discussed.

Spore liberation by water drops in some myxomycetes

Spore liberation by falling water drops has been demonstrated in four myxomycetes. In Lycogala epidendrum not only does the aethalium behave as a puff-ball bellows mechanism operated by falling drops, but the ostiole through which the spores escape is itself produced by drop bombardment. In Fuligo septica and Tubifera ferruginosa the aethalium is ruptured by impacting water drops and clouds of spores are released. In Leocarpus fragilis the water drop acts as a crushing agent rupturing the individual sporangia and exposing the spores.