摘要:

A diverse assemblage of coalified sporangia from Lochkovian/Gedinnian, fluvial rocksimicrornatus‐newportensisSpore Biozone) contains fusiform forms assignable toSalopellaEdwards&Richardson andTortilicaulisEdwards. Both show bifurcation within some sporangia. In specimens assigned toSalopellacf.marcensis, longitudinal dehiscence produces two equal valves revealing spores resemblingAneurospora, although trilete marks may be difficult to distinguish. The spores are in two forms with distal ornament of either coarse or fine coni, each occurring in separate sporangia. A further sporangium ofSalopellashape contains distally apiculate, hilate cryptospores. Elongate sporangia exhibiting spiralling of superficial cells and sometimes gross twisting, are placed in a new species ofTortilicaulii, T. offaeus.Anatomical data include details of irregularly thickened epidermal cells, sporangial wall andin situspores. The latter are trilete, equatorially thickened and highly distinctive, because the entire exospore surface is covered with grana, a feature not common in dispersed spores of this age. The nomenclatural and curatorial problems associated with these small, coalified fossils, whose anatomical examination by scanning electron microscope necessitates elimination of gross morphology, are discusse

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1994.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The anatomy and micromorphology of eleven species ofEugeniafound in the ‘restinga’ of Marica, Rio de Janeiro, Brazil, were studied and compared. The characteristics found to be of most use in distinguishing the species are: presence and types of trichomes persistent in the adult material, form and arrangement of overlying cells (epidermal cells over secretory cavities), pattern of anticlinal walls of epidermal cells (primary sculpturing), occurrence of epicuticular striae and folds (secondary sculpturing) and presence of peristomatal folds. An analytical key based on these characteristics is presented for theEugeniaspecies stud

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1994.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Linaria arabinianasp. nov. is described from coastal sand dunes of a very reduced area in Alicante Province (south‐eastern part of the Iberian Peninsula). It is a perennial herb characterized by its 3–4‐verticillate leaves, glabrous stems, large violet or rarely yellow flowers, and bicoloured usually flat seeds. Morphological characteristics and taxonomic affinities of this taxon are discussed, as are data on its ecology, phytosociology, and eventual conservation fea

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1994.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A study of the embryology ofPlagiopteron suaveolensGriffith is presented in order to evaluate the affinities of the genus. Anther wall formation is of the dicotyledonous type. The anther tapetum is glandular and its cells become two to four nucleate. Cytokinesis in the microspore mother cell is simultaneous and the resultant tetrad is tetrahedral. The mature pollen grains are two‐celled. The anther has 4‐locules at anthesis. The ovule is anatropous, bitegmic and weakly crassinucellate with only one cell‐layered parietal tissue. The micropyle is zig‐zag in section and formed by both inner and outer integuments which are three and three to four cell layers thick respectively. The megaspore archesporium is one‐celled and the embryo sac development is of the Polygonum type. An endothelium is formed with early disintegration of nucellar tissue. The antipodals multiply to 15 to 20 cells. Embryological evidence supports the placement ofPlagiopteronin its own family, Plagiopteraceae, with closest relationship with Celastraceae and close relationship with Elaeocarpaceae, Rhizophoraceae and some families of the G

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1994.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY