THE ZYGOSPORIC STAGE OF THE GENUS PIRELLA (MUCORACEAE)

Hesseltine , C. W. (Northern Utilization Research and Development Division, Peoria, Ill.) The zygosporic stage of the genus Pirella (Mucoraceae). Amer. Jour. Bot. 47(3) : 225—230. Illus. 1960.–Pirella circinans Bainier has been found to be heterothallic. The zygospores, which have never before been reported, are formed when + and – strains are mated at 15°C. on such media as tomato paste-oatmeal or potato dextrose agars. Zygospores are formed in a diffuse manner in the aerial mycelium and are similar to those found in the genus Mucor. The single species, P. circinans, is described on a synthetic medium and its synonyms are listed. It is believed to represent a genus between Mucor and the family Thamnidiaceae.     

PREDAEA WELDII,A NEW SPECIES OF RHODOPHYTA FROM HAWAII,WITH AN EVALUATION OF THE GENUS1

A new species of Predaea (Gigartinales, Rhodophyta) is described from Hawaii. It is compared in important morphological details with other species of the genus, all of which are distributed in the subtropics. Predaea is likewise compared to the genera of Nemastomataceae, and should be included in that family. The genus Yadranella Ercegovic (Nemaliales, Rhodophyta) is placed in synonymy with Predaea.     

MEDULLARY BUNDLES IN THE GENUS DAHLIA AND THEIR POSSIBLE ORIGIN

Davis , Edward L. (U. Massachusetts, Amherst.) Medullary bundles in the genus Dahlia and their possible origin. Amer. Jour. Bot. 48(2): 108–113. Illus. 1961.—The system of medullary bundles which extends throughout the stem and into the leaves and branches in D. lehmanni is described. It is suggested that this system may have arisen from leaf traces and that the condition in D. scapigera var. scapigera f. merckii and D. coccinea, in which leaf traces fail to develop secondary tissue while adjacent bundles are increasing in diameter, may represent the incipient stage of development of medullary bundles within the genus. The correspondence between the occurrence of medullary bundles and the sectional division of the genus on taxonomic grounds by Sherff is noted.     

中国石蕊科地衣研究之三 中国新记录属:扇盘衣属

本文报道了主要分布于澳洲的扇盘衣属地衣,缝裂扇盘衣在中国的首次发现,从而为中国地衣区系增加了一个新记录属。文中报道的该属的地衣不仅在中国,即使在世界范围也十分珍异。因而,对于该属及种的特征从形态学、解剖学与化学方面给以简要描述。     

THE BALLISTOSPORIC PROTOSTELID GENUS SCHIZOPLASMODIUM

The genus Schizoplasmodium is a member of the Protostelia, a primitive subclass of mycetozoans. It has previously been known only from the commonly occurring type species, S. cavostelioides Olive and Stoianovitch. Two additional species of rare occurrence are described here—S. obovatum, found on bark of living trees in Florida and Uganda, and S. sechellarum, found in the Seychelles Islands and Papua New Guinea on old corn and leguminous capsules. All three members of the genus produce reticular plasmodia but lack flagellate cells. The most unusual feature of the group is the production of ballistospores that are discharged from their stalks by the development and explosion of gas bubbles.     

A COMMENT ON THE STATUS AND DISTRIBUTION OF THE GENUS PARATYLODIPLAX SERENE (BRACHYURA: OCYPODIDAE) IN SOUTHERN AFRICA

Summary

The ocypodid genus Paratylodiplax was described in 1974 and contains four species, three of which are endemic to southern Africa where they form an important component of the estuarine benthic fauna. However, very little is known about the biology and ecology of the genus, with discrepancies existing between the commonly quoted distributions and actual records of the species. This comment outlines the current taxonomic status of the genus and attempts to resolve the discrepancies in the distributions of the southern African species Paratylodiplax blephariskios has been recorded from the Morrumbene estuary in Mozambique to the Mngazana estuary in the eastern Cape, while the distributions of P. algoensis and P. edwardsii are given as being from the Mngazana to the Eerste estuary and Langebaan Lagoon in the western Cape respectively.     

NOTES ON SOME GRASSES. XVI. EMBRYO STRUCTURE OF THE GENUS ORYZA IN RELATION TO THE SYSTEMATICS

Three distinct types of embryo have been found in 18 species of the genus Oryza. Type 1 is characterized by lateral fusion of the epiblast and the scutellum and also by the development of auricles. Type 2 has no auricle, and the epiblast is not laterally fused with the scutellum. Type 3 has a cleft between the lower part of the scutellum and the coleorhiza, a long epiblast which is free from the scutellum, and lacks auricles. Type 1 has been found in 13 species of section Sativae, Type 2 in 4 species of sections Granulatae and Coarctatae, and Type 3 in O. coarctata only. The results indicate that species of section Sativae are more or less closely related, while section Coarctatae is a heterogeneous group. A new section, Ridleyianae, has been described for Oryza ridleyi and some other species. Oryza coarctata has unique features in embryo structure, morphology and leaf anatomy, and this species has been moved from the genus Oryza to a separate genus, Sclerophyllum, which is here revived.     

CHROMOSOME COUNTS IN CHEILANTHES AND ASPIDOTIS WITH A CONSPECTUS OF THE CYTOLOGY OF THE SINOPTERIDACEAE

Confirmatory, corrective and new chromosome counts are listed for species in the genus Cheilanthes, and a new chromosome count is given for a member of the genus Aspidotis. An analysis of five collections of C. castanea revealed no significant morphological differences despite the different chromosome numbers. The ploidy level of all known species in genera of the Sinopteridaceae is summarized, revealing directions in which future research might proceed to complete our cytological knowledge of this family.     

SPORE MORPHOLOGY IN THE CYATHEACEAE. III. THE GENUS TRICHIPTERIS

Scanning electron microscopy supported by light microscopic L-O analysis is used in a palynological study of the genus Trichipteris of the tree fern family Cyatheaceae. The spores of all but two of the 55 species are investigated and the results are related to previous findings for Trichipteris species in the literature. A perine layer consisting of a network of slender, smooth- or rough-textured interlocking strands with free ends uniformly characterizes the genus and is the same as the perine type previously reported in neotropical species of Sphaeropteris excluding the S. horrida group. The exine is analyzed both in spores which have not yet developed the perine layer and in spores whose perine has been removed by chemical treatment. Exine sculpturing shows great variation in the genus, ranging from essentially psilate to variously pitted (foveolate, foraminate), with topography ranging from plane to verrucate-tuberculate, and with the verrucae-tubercles themselves often variously pitted. In many instances, exine sculpturing types correlate with the infrageneric species groupings or affinities hypothesized by the recent monographers. In other cases, palynological characters offer new insight into species relationships that were previously unclear to monographers or that were interpreted differently on the basis of other characters. The exine sculpturing types reinforce the relationship evident between Trichipteris and neotropical Sphaeropteris on the basis of perine morphology.     

ANATOMICALLY PRESERVED SEED CONES OF THE PINACEAE FROM THE EARLY CRETACEOUS OF VIRGINIA

A collection of anatomically preserved conifer cones from the Early Cretaceous of Virginia contains two new species of the extinct pinaceous genus Pityostrobus. Superficially, the fossil cones resemble those of modern species of Picea. However, the fossils reveal such a peculiar mixture of anatomical features that they cannot be assigned to any extant genus of the Pinaceae. One of the new species, Pityostrobus hueberi, is most comparable with Pityostrobus corneti Alvin from the Early Cretaceous of Belgium. Pityostrobus virginiana, the other new species, differs from all other members of the genus in only slight—but nonetheless significant—attributes. Pityostrobus hueberi and P. virginiana are the first species of this genus to be reported from Early Cretaceous sediments of the North American Atlantic Coastal Plain. As such, they increase our knowledge of the structural variation exhibited by ancient members of the Pinaceae.     

A STUDY ON THE GENUS BRYOMYIA KIEFFER (DIPTERA: CECIDOMYHDAE) FROM CHINA*

Abstract Four Chinese species of genus Bryomyia Kieffer are recorded in the present paper, among which, one species: B. puberula Li et Bu is described as new to science; two species; B. bergrothi Kieffer and B. gibbosa (Felt) are recorded for the first time from China. Key to the known Chinese species of the genus is given. Type specimen is deposited in the Department of Biology, Nankai University, Tianjin, China.     

POLLEN ORGANS OF THE PENNSYLVANIAN CALLISTOPHYTACEAE (PTERIDOSPERMOPSIDA)

Numerous specimens of the pteridospermous pollen organs Idanothekion glandulosum and Callandrium callistophytoides are present in Middle and Upper Pennsylvanian petrifaction material, respectively. Several specimens of Idanothekion, previously known only in an isolated condition, are attached to foliage assignable to the monostelic seed fern Callistophyton. Proof of the affinities of Idanothekion allows this genus to be elevated from a form genus to an organ genus in the Callistophytaceae. The structure of the foliage and the mode of attachment of the Idanothekion specimens are like those previously described for Callandrium. Structural features of Idanothekion and Callandrium are compared, and the question of their identity is discussed. At present one basic type of pollen organ, borne on the abaxial surface of foliar pinnules, is known for members of the Callistophytaceae.     

THE NODULAR MYCORRHIZAE OF PODOCARPUS ROSPIGLIOSII

Podocarpus is a genus of southern hemisphere and tropical conifers which are often important timber trees in their respective ranges. Nodular short-roots were early noted as being similar in gross aspect to legume nodules, and it was inferred that they are Rhizobium-bearing symbiotic structures which fix atmospheric nitrogen. In histological section the nodular short-roots of the Venezuelan species Podocarpus rospigliosii were shown to contain endotrophic mycorrhizae. In a Koch's Postulates test, a fungus isolated from Podocarpus induced the formation of nodular structures on aseptic seedlings. A Nitrogen¹⁶ test was negative for fixation of atmospheric N₂. Recent work in New Zealand has shown comparable histology in other species of the genus. The mycorrhizae may be important in forestry practice, though not as a source of nitrogen.     

THE PHYLOGENETIC POSITION OF ANEMIA COLIMENSIS

The unique leaf structure of the genus Anemia with its upright fertile basal pinnae has been interpreted as derived from the typical fern leaf with unmodified basal pinnae. Reported herein for the first time is the leaf morphology of a species, Anemia colimensis Mickel, which shows the most primitive condition known in the genus and clearly confirms the course of evolution. The fertile pinnae are but little modified in size, lamination, and posture. Although A. colimensis has characters of two subgenera, it is shown to be a primitive element in subgen. Anemiorrhiza and not a member of subgen. Coptophyllum as previously reported.     

ADAPTATION IN THE GENUS PHYLLOSCOPUS

The paper describes variation among species of the genus Phylloscopus in weight, relative wing-, tail-, tarsus-, and bill-length, tail/wing ratio and degree of roundness of the wing, wing formula, emargination, and plumage colour. This variation is compared with differences in niche preference within the genus, and relationships between niche, feeding strategies, and morphology are suggested. It is concluded that evolution within the genus has taken place mainly through the development of different feeding strategies, to suit the structural properties of different niches, without altering the range of size of the prey. The genus Sylvia is treated briefly in order to provide comparison, and other genera of Sylviinae are discussed where parallel adaptation seems likely.     

REPRODUCTIVE DEVELOPMENT OF THE PARASITIC RED ALGA GARDNERIELLA TUBERIFERA (SOLIERIACEAE,GIGARTINALES)1

Examination of the reproductive morphology of the adelphoparasitic red alga Gardneriella tuberifera Kylin reveals that this monotypic genus is correctly placed in the family Solieriaceae (Gigartinales), to which its host Agardhiella gaudichaudii (Montagne) Silva et Papenfuss also belongs. Gardneriella is multiaxial, nonprocarpic and has an inwardly directed, three-celled carpogonial branch. The large, reniform uninucleate auxiliary cell is distinct prior to and after fertilization. It is diploidized by an unbranched, multicellular connecting filament which lacks pit connections. One or two connecting filaments arise from each fertilized carpogonium. From the diploidized auxiliary cell, the gonimoblast initial is cut off obliquely toward the interior of the thallus. The cells of the gonimoblast fuse with adjacent unpigmented vegetative cells of Gardneriella and pigmented cells of the host. These cells become incorporated into the developing cystocarp and, from those of Gardneriella, additional short chains of gonimoblast cells arise. The mature cystocarp is placentate, radiately lobed, and lacks a surrounding involucre. Carposporangia are borne in short chains and the unpigmented carpospores are released upon the dissolution of outer vegetative cells. No ostiole is present. Gardneriella appears to be most closely related to the placentate solieriacean genera Agardhiella, Sarcodiotheca, and Meristiella and therefore this genus should be placed in the tribe recently erected for these taxa, the Agardhielleae.     

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.     

BRASILONEMA ANGUSTATUM SP. NOV. (NOSTOCALES), A NEW FILAMENTOUS CYANOBACTERIAL SPECIES FROM THE HAWAIIAN ISLANDS1

A new filamentous cyanobacterial species of the genus Brasilonema was isolated from the island of Oahu, Hawaii. The taxon is distinguished from the seven other species in the genus by attenuation of trichomes, and is here described as Brasilonema angustatum sp. nov. It possesses the cytoplasmic kerotimization and reddish‐brown coloration of several species in the genus. Phylogenetic analysis based on 16S rRNA gene sequence shows B. angustatum within a highly supported clade containing all sequenced Brasilonema species. We compared the secondary structure of the 16S–23S ITS regions for B. octagenarum and B. angustatum. The structurally conservative D1–D1′ and V3 helices show similar motifs between the two taxa, but differ structurally and in sequence, providing additional justification for erection of the new species. The Box‐B helix has identical secondary structure. The existence of tapering in a Brasilonema species is unique in this genus, and requires modification of the current concept of the genus Brasilonema, which was described as being unattenuated. Our phylogenetic evidence supports the hypothesis that tapering has developed repeatedly in separate cyanobacterial lineages and lacks the taxonomic significance once assumed by early workers.