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.

A Contribution to Our Knowledge of the Anatomy of Botryopteris

Sergius H. Mamay and Henry N. Andrews, Jr.
Bulletin of the Torrey Botanical Club
Vol. 77, No. 6 (Nov. - Dec., 1950), pp. 462-494
Published by: Torrey Botanical Society
DOI: 10.2307/2482182
Stable URL: http://www.jstor.org/stable/2482182
Page Count: 33
  • Read Online (Free)
  • Download ($10.00)
  • 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.
A Contribution to Our Knowledge of the Anatomy of Botryopteris
Preview not available

Abstract

Briefly, the various points of interest concerning the ramifications of this plant are as follows: 1. Petiolar segments depart from the cauline stele at angles of approximately 120⚬ from each other; the nodes are an average of 5 or 6 mm. apart. 2. Each petiolar segment undergoes a trisection soon after departing from the stele. The median segment ultimately assumes the fluted W-shape with the xylem arms pointing adaxially; this structure is designated the petiolar trace. 3. Each lateral segment resulting from the petiolar trisection soon undergoes a corresponding trisection resulting in three secondary pinnae, the median one of which assumes the W-shape with the xylem arms pointing toward the xylem strand from which it arose. 4. The behavior of the distal and proximal secondary pinnae (especially the latter) is variable when compared with that of the median pinna. They have been observed to behave thus: a. The distal secondary pinna trace is not known to assume the W-shape but remains terete. It may either di- or trichotomize, giving rise to tertiary pinnae with extremely small terete vascular strands. b. The proximal secondary pinnae usually display a stem-like aspect. They undergo successive divisions involving either equal or unequal dichotomy. One branch of the dichotomy continues vertically, the weaker one departing horizontally or assuming a pendant position and sometimes dichotomizing. In one instance the proximal pinna is known to assume the fluted shape of the central petiolar trace, one xylem arm giving off a small terete strand. 5. Small adventitious roots are rather sparingly given off, sometimes at random and sometimes in pairs closely associated with the nodes.

Page Thumbnails

  • Thumbnail: Page 
462
    462
  • Thumbnail: Page 
463
    463
  • Thumbnail: Page 
464
    464
  • Thumbnail: Page 
465
    465
  • Thumbnail: Page 
466
    466
  • Thumbnail: Page 
467
    467
  • Thumbnail: Page 
468
    468
  • Thumbnail: Page 
469
    469
  • Thumbnail: Page 
470
    470
  • Thumbnail: Page 
471
    471
  • Thumbnail: Page 
472
    472
  • Thumbnail: Page 
473
    473
  • Thumbnail: Page 
474
    474
  • Thumbnail: Page 
475
    475
  • Thumbnail: Page 
476
    476
  • Thumbnail: Page 
477
    477
  • Thumbnail: Page 
478
    478
  • Thumbnail: Page 
479
    479
  • Thumbnail: Page 
480
    480
  • Thumbnail: Page 
481
    481
  • Thumbnail: Page 
482
    482
  • Thumbnail: Page 
483
    483
  • Thumbnail: Page 
484
    484
  • Thumbnail: Page 
485
    485
  • Thumbnail: Page 
486
    486
  • Thumbnail: Page 
487
    487
  • Thumbnail: Page 
[488]
    [488]
  • Thumbnail: Page 
489
    489
  • Thumbnail: Page 
490
    490
  • Thumbnail: Page 
491
    491
  • Thumbnail: Page 
492
    492
  • Thumbnail: Page 
493
    493
  • Thumbnail: Page 
494
    494