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Observations on the Lower Carboniferous Lycopod Oxroadia gracilis Alvin

Published online by Cambridge University Press:  03 November 2011

Albert G. Long
Albert G. Long
Affiliation:
33 Windsor Crescent, Berwick-upon-Tweed, Northumberland TD15 INT, England.
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Abstract

A stem-base of Oxroadia gracilis is described showing 12 distal rhizophores and 72 roots. The rhizophores branch in a manner interpreted as dichotomy in successive planes at right angles. Each has a siphonostele which may possess medullary tracheids. Root-traces are monarch and wedge-shaped in section and their departure leaves ramular gaps in the siphonostele. The largest root may have functioned as a tap-root formed earlier than the rhizophores and exogenous. Only two out of ten known rooting specimens show rhizophores.

An aerial stem with leaves shows secondary xylem up to the level of the probable second dichotomies.

Leaves have slightly decurrent clasping bases forming low cushions and are recurved. Ligules (when preserved) occur in deep cavities of leaf-bases. In the apical region young leaves are small, recurved, and grooved distally below, giving a pseudo-forked appearance in cross sections of the stem.

Only incomplete strobili are known.

Comparisons are made with ‘Lepidodendron’ saalfeldense Solms-Laubach, and Trabicaulis ftabellilignis Meyer-Berthaud; these are considered co-generic.

Oxroadia is recorded from the Oil-Shale Group (late Viséan or Asbian) near Kinghorn, Fife, Scotland; and from the Cementstone Group (late Tournaisian or Courceyan) East Lothian, Scotland; Berwickshire, Scotland; and Northumberland, northern England.

Keywords

Cementstone Groupligulemonarch rootOil-shale GrouprhizophoresiphonosteleStigmaria.
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 77 , Issue 2 , 1986 , pp. 127 - 142
Copyright
Copyright © Royal Society of Edinburgh 1986

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References

Alvin, K. L. 1965. A new fertile lycopod from the Lower Carboniferous of Scotland. PALAEONTOLOGY 8, 281–93.Google Scholar
Beck, C. B. 1958. Levicaulis arranensis gen. et sp. nov., a lycopsid axis from the Lower Carboniferous of Scotland, TRANS R SOC EDINBURGH 63, 445–57.Google Scholar
Calder, M. G. 1934. Notes on the Kidston Collection of Fossil Plant Slides: No. VI, On the Structure of Two Lepidodendroid Stems from the Carboniferous Flora of Berwickshire. TRANS R SOC EDINBURGH 58, 118–34.Google Scholar
Crookall, R. 1964. Fossil Plants of the Carboniferous Rocks of Great Britain. MEM GEOL SURV GB Palaeontology. IV (3), 328–332.Google Scholar
Danzé-Corsin, P. 1958a. Observations sur les formes lepidodendroïdes du Dévonien supérieur et du Dinantien (Culm). BULL SOC BOT NORD FRANCE 11, 39–54.Google Scholar
Danzé-Corsin, P. 1958b. Nouvelle classification des lépidophytes du Primaire. C R ACAD SCI PARIS 247, 1226–9.Google Scholar
Eggert, D. A. 1961. The ontogeny of Carboniferous arborescent Lycopsida. PALAEONTOGRAPHICA B108 43–92.Google Scholar
Frankenberg, J. M. & Eggert, D. A. 1969. Petrified Stigmaria from North America. Part 1. Stigmaria ficoides, the underground portions of Lepidodendraceae. PALAEONTOGRAPHICA B128 1–47.Google Scholar
Grierson, J. D. & Banks, H. P. 1963. Lycopods of the Devonian of New York State. PALAEONTOGR AM 4, 217–95.Google Scholar
Jennings, J. R. 1975. Protostigmaria, a new plant organ from the Lower Mississipian of Virginia. PALAEONTOLOGY 18, 19–24.Google Scholar
Jennings, J. R., Karrfalt, E. E. & Rothwell, G. R. 1983. Structure and affinities of Protostigmaria eggertiana. AM J BOT 70, 963–74.Google Scholar
Karrfalt, E. 1984a. The origin and early development of the root-producing meristem of Isoetes andicola L. D. Gomez. BOT GAZ 145 372–7.Google Scholar
Karrfalt, E. 1984b. Further observations on Nathorstiana (Isoetaceae). AM J BOT 71, 1023–30.Google Scholar
Kidston, R. 1905. On the internal structure of Sigillaria elegans of Brongniart's “Histoire des Végétaux Fossiles”. TRANS R SOC EDINBURGH 41, 533.Google Scholar
Kräusel, R. & Weyland, H. 1949. Pflanzenreste aus dem Devon. XIV. Gilboaphyton und die Protolepidophytales. SENCKENBERGIANA 30, 129–52.Google Scholar
Lacey, W. S. 1962. Welsh Lower Carboniferous plants. I. The flora of the Lower Brown Limestone in the Vale of Clwyd, North Wales. PALAEONTOGRAPHICA B111, 125–60.Google Scholar
Leclercq, S. 1930. A Monograph of Stigmaria bacupensis Scott et Lang. ANN BOT 44, 31–54.Google Scholar
Lele, K. M. & Walton, J. 1962. Fossil Flora of the Drybrook Sandstone in the Forest of Dean, Gloucestershire. BULL BR MUS NAT HIST 7, 137–52.Google Scholar
Lindley, J. & Hutton, W. 1833. The Fossil Flora of Great Britain. ii, 1–3. London: Cambridge University Press.Google Scholar
Long, A. G. 1964. A petrified Lower Carboniferous Lepidodendron showing rooting organs identified with Calamopsis Solms-Laubach. TRANS R SOC EDINBURGH 66, 35–48.Google Scholar
Long, A. G. 1971. A new interpretation of Lepidodendron calamopsoides Long and Oxroadia gracilis Alvin. TRANS R SOC EDINBURGH 68, 491–506.Google Scholar
Meyer-Berthaud, B. 1984. Les axes de Lycophytes à structure anatomique conservée du Carbonifère basal (Tournaisien) de la Montagne Noire: Trabicaulis gen. nov. et Landeyrodendron gen. nov. PALAEONTOGRAPHICA Abt. B190, 1–36.Google Scholar
Phillips, T. L. & Leisman, G. A. 1966. Paurodendron, a rhizomorphic lycopod. AM J BOT 53, 1086–1100.Google Scholar
Pigg, K. B. & Rothwell, G. W. 1979. Stem-root transition of an Upper Pennsylvanian woody lycopsid. AM J BOT 66, 914–24Google Scholar
Pigg, K. B. & Ruthwell, G. W. 1983. Chaloneria gen. nov., heterosporous lycophytes from the Pennsylvanian of North America. BOT GAZ 144, 132–47.Google Scholar
Richter, R. & Unger, F. 1856. Beitrag zur Paläontologie des Thüringer Waldes. DENKSCHR AKAD WISS, Wien 11, 172–73, Taf. viii, fig. 18.Google Scholar
Rothwell, G. W. & Erwin, D. M. 1985. The rhizomorph apex of Paurodendron; implications for homologies among the rooting organs of Lycopsida. AM J BOT 72, 86–98.Google Scholar
Scott, A. C., Galtier, J. & Clayton, G. 1984a. Distribution of anatomically preserved floras in the Lower Carboniferous in Western Europe. TRANS R SOC EDINBURGH EARTH SCI, 75, 311–40.Google Scholar
Scott, A. C., Meyer-Berthaud, B., Galtier, J. & Rex, G. 1984b. Studies on Scottish Lower Carboniferous floras: a new assemblage from Kinghorn, Fife. ABST 2nd INT ORG PALAEOBOT CONF EDMONTON 1984, 37.Google Scholar
Scott, D. H. 1908. Studies in Fossil Botany 2nd edn. London: Black.Google Scholar
Seward, A. C. 1910. Fossil Plants vol. 2.Google Scholar
Solms-Laubach, H.zu, Graf 1896. Ueber die seinerzeit von Unger beschriebenen strukturbietenden Pflanzenreste des Unterculm von Saalfeld in Thuringen. ABH PREUSS GEOL LANDESANST 23, 1–100.Google Scholar
Stewart, W. N. 1983. Paleobotany and the evolution of plants. Cambridge: Cambridge University Press.Google Scholar
Stubblefield, S. P. & Rothwell, G. W. 1981. Embryogeny and reproductive biology of Bothrodendrostrobus mundus (Lycopsida). AM J BOT 68, 625–34.Google Scholar
Thomas, B. A. & Brack-Hanes, S. D. 1984. A new approach to family groupings in the lycophytes. TAXON 33, 247–55.Google Scholar
Walton, J. 1935. Scottish Lower Carboniferous Plants: The fossil hollow trees of Arran and their branches (Lepidophloios wiinschianus Carruthers). TRANS R SOC EDINBURGH 58, 313–37.Google Scholar
Watson, D. M. S. 1908. The cone of Bothrodendron mundum (Will.). MEM PROC MANCHESTER LIT PHIL SOC 52 (3), 1–16.Google Scholar
Weiss, F. E. 1908. A Stigmaria with Centripetal Wood. ANN BOT 22, 221.Google Scholar
Weiss, F. E. 1929. On the Occurrence of Stigmaria Lohesti Suz. Lecl. in the British Coal Measures. MEM PROC MANCHESTER LIT PHIL SOC 73, 129–34.Google Scholar
Weiss, F. E. 1932. A Re-examination of the Stigmaria Problem, PROC LINN SOC LONDON 144, 151–66.Google Scholar
Williamson, W. C. 1878. On the organisation of the Fossil-plants of the Coal-measures. IX. PHIL TRANS R SOC LONDON 169, 319–64.Google Scholar
Williamson, W. C. 1889. On the organisation of the Fossil-plants of the Coal-measures. PHIL TRANS R SOC LONDON B180, 197–8.Google Scholar