Access

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 Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Iridopteris eriensis from the Middle Devonian of North America, with Systematics of Apparently Related Taxa

William E. Stein, Jr.
Botanical Gazette
Vol. 143, No. 3 (Sep., 1982), pp. 401-416
Stable URL: http://www.jstor.org/stable/2474838
Page Count: 16
  • Read Online (Free)
  • Download ($19.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Iridopteris eriensis from the Middle Devonian of North America, with Systematics of Apparently Related Taxa
Preview not available

Abstract

A reinvestigation of the permineralized axis Iridopteris eriensis Arnold, from type and new material, was conducted as part of a comprehensive study of all members of the Iridopteridineae of Arnold. The information presented here suggests that Iridopteris was a highly distinctive Middle Devonian plant with (1) a five-ribbed, mesarch, primary xylem column and apparent bilateral symmetry; (2) simple protoxylem strands, or cavities representing protoxylem strands, grouped in multiples near the tips of primary xylem ribs; (3) traces of two distinct sizes; (4) whorled order of trace departure; (5) metaxylem tracheids with circular to elongate elliptical bordered pit pairs with elliptical apertures; and (6) a distinct boundary between stele and cortex apparently comprised of a single layer of cells with dark materials in their lumina. Accumulating evidence suggests that a taxonomically distinct group of Middle and lower Upper Devonian plants has only partially been recognized. The Iridopteridales is here established to include the central concept of Arnold's Iridopteridineae, except for Reimannia, combined with directly comparable components of the Ibykales of Skog and Banks. Members of this new order include Arachnoxylon, Iridopteris, Ibyka, and Asteropteris.

Page Thumbnails

  • Thumbnail: Page 
401
    401
  • Thumbnail: Page 
402
    402
  • Thumbnail: Page 
403
    403
  • Thumbnail: Page 
404
    404
  • Thumbnail: Page 
405
    405
  • Thumbnail: Page 
406
    406
  • Thumbnail: Page 
407
    407
  • Thumbnail: Page 
[408]
    [408]
  • Thumbnail: Page 
409
    409
  • Thumbnail: Page 
410
    410
  • Thumbnail: Page 
411
    411
  • Thumbnail: Page 
412
    412
  • Thumbnail: Page 
413
    413
  • Thumbnail: Page 
414
    414
  • Thumbnail: Page 
415
    415
  • Thumbnail: Page 
416
    416