PALAEOBOTANICAL RESEARCH   GROUP
 
UNIVERSITY  MÜNSTER
THE   RHYNIE  CHERT  AND  ITS  FLORA
 
II. THE  RHYNIE  CHERT  FLORA
 
In addition to vascular plants, many fungi, algae and even the earliest well-documented lichens have been described  from the Rhynie Chert.  The latter is a typical example of a symbiosis of a fungus and algae or cyanobacteria.  Also other examples of interactions between fungi, land plants and animals, e.g.,  parasitism and  saprophytism have been documented from the Rhynie Chert.  Six different types of sporophytes and three gametophytes have been described.  Because the recent drillings have cored several previously unknown chert horizons, it might well be possible that new plant  species can be found; from the nearby Windyfield Chert a new genus of zosterophylls has been reported recently.  Many  of the plants in the cherts occur in life position.   
Left: A piece of Rhynie Chert with several horizons, including upright standing Aglaophyton major axes (above) 
The following plants have been reported from the Rhynie Chert:
 
  Cyanobacteria: 
  • Archaeothrix contexta
  • Archaeothrix oscillatoriformis
  • Kidstoniella fritschii
  • Langiella scourfeldii
  • Rhyniella vermiformis
  • Rhyniococcus uniformis
Fungi: 
  • Allomyces sp.
  • Glomites rhyniensis
  • Krispiromyces discoides
  • Milleromyces rhyniensis
  • Palaeoblastocladia milleri
  • Palaeomyces agglomerata
  • Palaeomyces asteroxyli
  • Palaeomyces gordonii
  • Palaeomyces horneae
  • Palaeomyces simpsonii
  • Palaeomyces simpsonii
  • Several Chytridiomycetes
  • Ascomycetes
  • Various other undescribed fungi
Lichens: 
  • Winfrenatia reticulata
 Nematophytes: 
  • Nematophyton taitii
  • Nematoplexus rhyniensis
Algae s.l.: 
  • Mackiella rotundata
  • Palaeonitella cranii
  • Rhynchertia punctata
Tracheophytes (Sporophytes): 
  • Aglaophyton major
  • Asteroxylon mackiei
  • Horneophyton lignieri
  • Nothia aphylla
  • Rhynia gwynne-vaughanii
  • Trichopherophyton teuchansii
  • A still unnamed Zosterophyll
Tracheophytes (Gametophytes): 
  • Langiophyton mackiei
  • Lyonophyton rhyniensis
  • Kidstonophyton discoides
  • Still undescribed female gametophyte of Aglaophyton major
  • Still undescribed male gametophyte of Horneophyton lignieri 
 
 
List of plants described from the Rhynie Chert
 

 
The vascular land plants were small, ca. 10 to 40 cm high.  Except for one species, all higher land plants were leafless and all had bifurcating aerial axes with terminally and/or laterally attached sporangia with thick multilayered walls.  All species had clonal growth which means that aerial axes (daughter plants) developed from the rhizomatic axes of the mother plant.  Each species had its characteristic growth form, which indicates that each was well adapted to a specific habititat.  Some species had long-living aerial axes whereas others had seasonal aerial axes.  Two species lived entirely subaerial (Rhynia gwynne-vaughanii und Aglaophyton major), two had a subterranean rhizome (Nothia aphylla, Horneophyton lignieri), whereas ones species had roots which penetrated the soil (Asteroxylon mackiei).  Adaptations of these early land plants to the substrate and the available groundwater were apparently still limited.  Each species has water-conducting cells with very typical wall thickenings that are very different from those of later vascular plants. 

The systematic position of a number of species is problematic, not because they are not well known but rather because suprageneric groups are poorly defined.  There is still much discussion on the classification of some of the Rhynie Chert plants.  At least two of the six natural species are classified within the group of the Rhyniophytes, one within the Zosterophyllophytes and one among the earliest lycopods.  Some of the Rhynie Chert plants will be briefly introduced on the following pages. 
 
 

Left: Reconstruction of Aglaophyton major, one of the most common plants in the Rhynie Chert
© Forschungsstelle für Paläobotanik, Westfälische Wilhelms-Universität Münster 
April 2000