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.

Cleistogamy and Chasmogamy in Bromus carinatus Hook. & Arn.

Jack R. Harlan
American Journal of Botany
Vol. 32, No. 2 (Feb., 1945), pp. 66-72
Stable URL: http://www.jstor.org/stable/2437112
Page Count: 7
  • Read Online (Free)
  • Download ($12.00)
  • 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.
Cleistogamy and Chasmogamy in Bromus carinatus Hook. & Arn.
Preview not available

Abstract

Observations were made on the appearance of cleistogamous florets in plants of Bromus carinatus grown under different environmental conditions. Comparisons were made at several stages of development between cleistogamous and chasmogamous panicles. Bromus carinatus is facultatively cleistogamous, producing both chasmogamous and cleistogamous florets on the same plant. Optimum conditions for flowering induce chasmogamy; adverse conditions induce cleistogamy. The developmental gradient in cleistogamous spikelets and inflorescences is much steeper than the gradient in the chasmogamous spikelets and inflorescences. Both types of florets may appear on the same panicle, due to an abrupt change in the developmental gradients at an early stage in the development of a panicle. This steepness of developmental gradient in cleistogamous spikelets is associated with marked precocity in maturation of both ovary and pollen. Morphologically, cleistogamous flowers differ from chasmogamous ones in having smaller floral organs, particularly anthers, stigmas, and lodicules.

Page Thumbnails

  • Thumbnail: Page 
66
    66
  • Thumbnail: Page 
67
    67
  • Thumbnail: Page 
68
    68
  • Thumbnail: Page 
69
    69
  • Thumbnail: Page 
70
    70
  • Thumbnail: Page 
71
    71
  • Thumbnail: Page 
72
    72