Species Of Riccia Research Articles

<strong>Notes on Venezuelan Ricciaceae (Marchantiophyta)</strong>

New data on Ricciocarpos natans and on five species in the genus Riccia are given, including four Riccia species new to Venezuela, all from the Orinoco flood plains. The number of Ricciaceae species known from Venezuela is presently eight.

Documents pour la connaissance des australiens (Hépatiques, Marchantiales) ouvelles récoltes. Taxons nouveaux. Commentaires morphologiques et écologiques.

The genus Riccia belongs to the order Marchantiales, to the suborder Ricciineae Buch, to the family Ricciaceae Reichenb. A “Revision of the genus Riccia (Hepaticae) in Australia” was published in 1980 by O. Na-Thalang. It contains the description of 33 species based on specimens preserved in Taylor's and Stephani's herbaria, in Na-Thalang's own collections and among material belonging to several collectors. Later, two new subgenera were created: Viridisquamata (Jovet-Ast 1984), Triseriata (Jovet-Ast 1996). Recently, R.D. Seppelt (1998) published new descriptions of previously known species collected in South Australia. However, a number of species remained unknown. The purpose of this work is to construct a key to the subgenera, describe some new species, indicate some new localities for known species, give indications of the ecology, origin and biogeography of the Australian Riccia species. The observations were based on specimens lent by different collectors: O.H. Volk, A. Breuil-See, Karsten, Dr Ducker, W.A. Weber and D. McVean, J.H. Willis, D.R. Selkirk. The characters for 3 recently described species are repeated: R. caroliniana, R. pullulans, R. singularis (Jovet-Ast 1984, 1996, 1997). Once more, the morphologies of R. bifurca and R. subbifurca are compared.

<p><strong>Taxonomic Results of the BRYOTROP Expedition to Zaire and Rwanda 8. Riccia vulcanicola E. Fischer (subgenus Ricciella, Sectio Cavernosae), a new species from the Virunga Volcanoes, Rwanda</strong></p>

A new Riccia species, R. vulcanicola is described and illustrated. It is closely related to R. crystallina, differing by the incomplete rosettes of the thallus and the larger and fewer areolae of the spores.

Two new species of the liverwort genusRicciaL. from tropical Africa:R. somaliensisandR. erubescens

Abstract Two new Riccia species, R. somaliensis and R. erubescens from Africa are described and illustrated. They are both classified in the subgenus Riccia, section Riccia. R. somaliensis has hyaline, somewhat frilly scales and apolar, wingless spores; R. erubescens has shiny dark, purple-red to bright cherry-red scales and polar, winged spores with numerous small areolae; its tissues are sometimes distorted by gelatinous globules that are gradually extruded on the dorsal surface.

A limited survey of the phylogenetic distribution of polyphenol oxidase

A variety of terrestrial and aquatic plant species were tested for the presence of polyphenol oxidase (PPO), using three different assay protocols. All aquatic green algae ( Chlorella, Stigeoclonium, Microspora, Ulva and Spirogyra) tested have no detectable PPO except for a Trebouxioid alga (lichen symbiont), and Coleochaete. Of the Charalean algae Chara and Nitella, only the latter had measurable activity. Some hepatics ( Conocephalum and Marchantia) possess the enzyme, but two species of Riccia tested do not. The anthocerotes Phaeoceros, Anthoceros and Notothylas have low, but easily detectable PPO. The mosses, Dicranum, Sphagnum and Thuidium, have no detectable activity. All of the ferns and fern allies tested have PPO activity. Among seed plants, PPO is undetectable in Ginkgo or any of the conifers tested. All but two species of the angiosperms surveyed possessed the enzyme. The M r as determined by semi-native electrophoretic mobility, ranged widely from 30 000 to 200 000, depending upon species. All species with PPO activity measured by spectrophotometric or gel assay had cytochemically-detected activity localized to the thylakoid membranes, with cytochemical product accumulating in the lumen of the thylakoid.

Studies in the genus <i>Riccia</i> (Marchantiales) from southern Africa. 18. New species in section <i>Pilifer</i> from the NW Cape: <i>R. furfuracea</i>, <i>R. vitrea</i> and <i>R. namaquensis</i>

Another three new species of Riccia in section Pilifer Volk are described from Namaqualand, namely R. furfuracea, R vitrea and R. namaquensis. There are certainly more undescribed species present in that region, but species from there are often very difficult to distinguish: almost all have hyaline scales, the free-standing dorsal cell pillars need to be examined in living plants and the spore ornamentation is quite variable.

Electrophoretic Studies in Riccia Subgenus Riccia (Hepaticopsida: Ricciaceae)

Electrophoretic variability in malate dehydrogenase (MDH) and peroxidase (PER) was surveyed among and within 14 described species of Riccia subgenus Riccia in the United States. Distinctive electrophoretic phenotypes were exhibited by 13 of these species. Distinctive MDH and PER phenotypes and contrasting ploidy levels support the recognition of R. dictyospora (n = 8) and R. mcallisteri (n = 16) as distinct species. Generally low but nevertheless contrasting levels of intraspecific MDH and PER variability exist among species. Geographically based genetic differ- entiation is evident in three species. Riccia L. is composed of small thallose liverworts with highly reduced sporophytes. Two subgenera, Riccia and Ricciella (A. Br.) Boulay, are generally recognized. Species of subgenus Riccia are terrico- lous and often inhabit sunny sites that are open due to shallow soil, aridity, or periodic disturbances.

Studies in the genus <i>Riccia</i> (Marchantiales) from southern Africa. 5. <i>R. rosea</i>, a new species

A new species of Riccia, R. rosea Volk Perold of the group 'Squamatae', section Riccia. subgenus Riccia. is described. It is endemic to southern Africa and is characterized by large ventral scales with hyaline margins and reddish pink to deep rose-pink bases, and bv the light green dorsal colour of the thallus. fading to white along the margins and older parts. Fertile male plants have prominent hyaline ostioles. The spores are globular or subglobular and apolar. with 9-11 well defined areolae across the diameter.

Studies in the liverwort genus <i>Riccia</i> (Marchantiales) from the south-west Cape

A new species of Riccia, R. parvo-areolata Volk Perold, as well as sporophytes and spores of R. villosa Steph. ex Brunnthaler, are described. Earlier descriptions of R. villosa were based on sterile plants. The unique structure of the dorsal epithelium consisting of loose cell pillars in these two species (and also present in allied species grouped together in the section Pilifer) is described and illustrated.

Key to Japanese species of Riccia

Key to Japanese species of Riccia

Effect of Nutritional Conditions on Sexual Reproduction in Riccia

Riccia duplex Lorbeer ex Miiller thallus branches elongate rapidly in the vegetative phase and much more slowly in the reproductive phase. Slow growth and sporophyte formation are brought about by low nutrient conditions, in particular low nitrate availability. In such conditions increasing daylength reduces the time for sporophyte formation. Two out of four clones of R. fluitans L. and one of two clones of R. rhenana Lorbeer ex Miiller formed archegonia when cultured on solutions providing low nutrient conditions. Antheridia were not formed on either of these two latter species under laboratory conditions. R. rhenana Lorbeer ex Miiller is not known to be fertile in nature. Miller (1941, 1954) gave extensive descriptions of four species of Riccia, R. fluitans L., R. rhenana Lorbeer ex Miiller, R. canaliculata Hoffm. and R. duplex Lorbeer ex Miller, which he treated as a species complex but separated clearly on the basis of chromosome number and fertility. Ricciafluitans (n = 8) and R. rhenana (n = 16) were only known sterile, while R. canaliculata (n = 8) and R. duplex (n = 16) were known to be fertile under natural conditions. More recent observations have made this relatively neat separation appear less convincing. After studies on artificially induced polyploidy of members of the R.fluitans group, Berrie (1964) concluded that R. rhenana is the diploid of R. fluitans and that R. duplex is the diploid of R. canaliculata (i.e. that the two infertile and the two fertile species form two separate polyploid series). Klingmiiller (1958) added to the R. fluitans group R. media, a new, though not widely accepted, European species (Bapna, 1961; Berrie, 1964). Bapna (1962) added an Indian species, R. abuensis, and Arnell (1963), a South African species, R. stricta, to the group. Meijer (1958) accepted the four member species of the group when considering European material, but returned to the R. fluitans sensu lato terminology when handling Indonesian material. He felt detailed studies of living material from many parts of its whole range would be needed for an understanding of the group. Riccia fluitans, sensu stricto, has until recently been regarded as always sterile. However, Paton (1973) described archegonia and sporophytes on both land and water forms from Britain; antheridia were not seen. Paton suggested that conditions at the site or in the local climate may suddenly have become favorable for the formation of sex organs, but did not suggest what conditions might have been important. 1 Thanks are due to Dr. D. Adamson, Dr. G. Berrie, Mr. J. Dickson, Dr. W. Klingmiiller, Mrs. E. Morris, Dr. S. Segal, Dr. Thai-thong, Mrs. C. Thomas, Dr. J. V~aia and Dr. E. Watson for collecting or supplying specimens. 2 School of Biological Sciences, Macquarie University, North Ryde, 2113. Australia. 0007-2745/79/037-046$1.25/0 This content downloaded from 207.46.13.176 on Mon, 20 Jun 2016 07:31:11 UTC All use subject to http://about.jstor.org/terms 38 THE BRYOLOGIST [Volume 82

A New Species of Riccia from Mount Abu (India)

Riccia jluilans has been an object of controversy for a long time in spite of various contributions made by Familler (1920), Gaisberg (1921), Evans (1921 ), Carter (1935), etc. Recendy the species has been considered (Lorbeer, 1934; Muller, 1940, 1941) to be a composite of four species, viz. Riccio jiuilans L. emend. K. MUller, R. rhenana Lorb., R. cana/iculala Hoffm., and R. duplex Lorb. The pioneer work of K. MUller, based upon cytological and cultural eXPeriments in segregating the 'fluitans group' into four species, is quite authentic (Meijer, 1951; Schuster, 1953; Klingmuller, 1957, 1959). Klingmuller (1958), while studying the taxonomy of' ftuitans group', recently instituted a new species, R. media KlingmUller, whose status is doubtful' (Bapna, 1961). No work has been done in India regarding these observations on 'ftuitans group' and the Indian material needs re-investigation. Kashyap (1929) described R.fluitans L. to occur as a sterile floating form and a fertile terrestrial form. The terrestrial form (Kashyap, 1929, p. 97), seems to be R. duplex Lorb. and the sterile one R. fluitans L. emend. K. Muller, but this could not be confirmed as the author failed to obtain the material. While studying the hepatic flora of Mount Abu, a hill station in Rajasthan (India), the author found a Riccia specimen of the 'ftuitans group' and described it as R.fluitans L. (Bapna, 1958, 1960). However, a detailed study has revealed that this specimen is composed of two species. The sterile one is R. fluilans L. emend. K. Milller, whereas the fertile one differs from all other species of the genus and deserves a separate treatment. Dr Arnell, to whom the material was sent for his valuable suggestions and advice, has also confirmed the determination. The plant is named as R. abuensis sp.nov. after the place of its occurrence, Mount Abu. The type specimen is deposited at the Herbarium of the National Museum of Natural History of Stockholm, Sweden. Riccia abuensis sp.nov.

A New Species of Riccia from the Ozarks

A New Species of Riccia from the Ozarks

A New Species of Riccia from the Ozarks

A New Species of Riccia from the Ozarks

Studies in Ricciaceae of East Pakistan: I. New and Little Known Species of Riccia

Studies in Ricciaceae of East Pakistan: I. New and Little Known Species of Riccia

Studies in Ricciaceae of East Pakistan: I. New and Little Known Species of Riccia

leaves imbricated, horizontally spreading, obliquely inserted on the stem, the antical margin crossing the axis, bordered by 1-3 rows of hyaline cells; the lobule averaging 0.9 mm. long and 0.78 mm. broad, ovate to ovate-oblong, apex rounded, margin entire; marginal cells 18.4 X 18.4-20.5 pt, middle 24.6 X 28.7 ?t and basal 26.6 X 50-53 ?t lobule variable, subparallel with the stem, ovate-lanceolate, about 0.33 mm. long, the apex with a hyaline papilla; female inflorescence on a short branch, innovating; perianth pyriform with a stout beak, slightly exserted, about 0.63 mm. long and 0.51 mm. wide, the capsule about 32.8 .t in diameter; male inflorescence on a short branch, bracts in 2-4 pairs, each bract subtending 2 antheridia. (FIG. 17-22.)

A Note on the Morphology of Some Species of Riccia

A Note on the Morphology of Some Species of Riccia

A Note on the Morphology of Some Species of Riccia

of the differences in the rate of evolution within some groups of biota, since few genera are known to include only two distinct species, one of which is morphologically less variable and restricted to a small area, while the other has a wide area of distribution including diverse climates, although its morphological variations are also small. Until such studies have been performed, Bryoxiphium continues to be one of the most unusual of the best-known genera of plants.

Riccia plana Tayl. Found in South America

A small collection of Hepaticae made by W. Herter of Montevideo was sent me from the Riksmuseum, Stockholm, for determination. It included, among other things, Riccia plana Tayl. from the following localities in Uruguay: Montevideo, Miguelete, 2030 m. alt. (no. 77,804) and Dep. de Colonia, Estanzuela, 10-50 m. alt. (no. 3,592). This widespread species of Riccia has not, as far as I know, been observed previously in South America. It is also known from Australia, South Africa and southern Europe. Of other Hepaticae in the collection the following may be noted: Oxymitra androgyna Bish. (84,991, Paraguay, Chaco, Rio Verde, 50-100 m. alt.); Riccia lindmnzanii St. (99,690, Uruguay, Dep. Canelones, 20-50 m. alt.; 83,058, Uruguay, Arroyo de Las Piedras, 25-50 m. alt.); Riccia austinii St. (99,729, Uruguay, Durazno, 150 m. alt.; 98,444, Uruguay, Dep. de Tacuarembo, Tambores, 300 m. alt.); Sphaerocarpus texanus Aust. (78,804, Uruguay, Montevideo, Miguelete, 20-30 m. alt.).

山西省産ウキゴケ屬の一新種

山西省産ウキゴケ屬の一新種