If you need an accessible version of this item please contact JSTOR User Support

Barthelia furcata gen. et sp. nov., with a Review of Paleozoic Coniferophytes and a Discussion of Coniferophyte Systematics

Gar W. Rothwell and Gene Mapes
International Journal of Plant Sciences
Vol. 162, No. 3 (May 2001), pp. 637-667
DOI: 10.1086/320129
Stable URL: http://www.jstor.org/stable/10.1086/320129
Page Count: 31
  • Download PDF
  • Cite this Item

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support
Barthelia furcata gen. et sp. nov., with a Review of Paleozoic Coniferophytes and a Discussion of Coniferophyte Systematics
Preview not available

Abstract

A conifer‐like plant occurs among the rich fossil biota at the Late Pennsylvanian–age Hamilton Quarry in southeastern Kansas. Barthelia furcata gen. et sp. nov. has irregularly branched shoots with both forked and simple leaves, simple pollen cones, and compound ovulate fructifications. Stems have an endarch eustele with dense wood surrounding a septate pith. Leaves range from ca. 1 to 5 cm long, display size‐related dimorphism, and have papillate epidermal cells with numerous trichomes and two adaxial stomatiferous bands. Stomatal complexes range from solitary to crowded, occur in longitudinal rows, and are represented by four to seven papillate subsidiary cells. Polar subsidiary cells are elongated parallel to the stomatal rows. Pollen cones are simple and have helically arranged sporophylls with a perpendicularly inserted shank, adaxial pollen sacs, and a forked distal lamina. Prepollen is monolete, monosaccate, and eusaccate. Ovulate fructifications comprise a compound conelike fertile zone of axillary dwarf shoots and extend into a vegetative zone distally. Ovuliferous dwarf shoots are radial, have numerous sterile scales, and occur in the axils of helically arranged bracts with forked tips. Ovules are apparently erect and borne on narrow sporophylls. They have a dense megaspore membrane and rounded micropylar end. The new species has a diagnostic suite of characters that falls outside the familial concepts of previously described spermatophytes. Bartheliaceae fam. nov. is compared to walchian conifers, ginkgophytes, cordaiteans, and other coniferophytic plants. The coniferophyte concept is reviewed, and the uncertain systematic relationships among coniferophytes are discussed.

Page Thumbnails

  • Thumbnail: Page 
1
    1
  • Thumbnail: Page 
2
    2
  • Thumbnail: Page 
3
    3
  • Thumbnail: Page 
4
    4
  • Thumbnail: Page 
5
    5
  • Thumbnail: Page 
6
    6
  • Thumbnail: Page 
7
    7
  • Thumbnail: Page 
8
    8
  • Thumbnail: Page 
9
    9
  • Thumbnail: Page 
10
    10
  • Thumbnail: Page 
11
    11
  • Thumbnail: Page 
12
    12
  • Thumbnail: Page 
13
    13
  • Thumbnail: Page 
14
    14
  • Thumbnail: Page 
15
    15
  • Thumbnail: Page 
16
    16
  • Thumbnail: Page 
17
    17
  • Thumbnail: Page 
18
    18
  • Thumbnail: Page 
19
    19
  • Thumbnail: Page 
20
    20
  • Thumbnail: Page 
21
    21
  • Thumbnail: Page 
22
    22
  • Thumbnail: Page 
23
    23
  • Thumbnail: Page 
24
    24
  • Thumbnail: Page 
25
    25
  • Thumbnail: Page 
26
    26
  • Thumbnail: Page 
27
    27
  • Thumbnail: Page 
28
    28
  • Thumbnail: Page 
29
    29
  • Thumbnail: Page 
30
    30
  • Thumbnail: Page 
31
    31