Matyas Buzgo, University of FloridaFollow
Douglas E. Soltis, University of Florida
Pamela S. Soltis, University of Florida
Sangtae Kim, University of Florida
Hong Ma, Pennsylvania State University
Bernard A. Hauser, University of Florida
Jim Lebens-Mack, Pennsylvania State University
Bo Johansen, University of Copenhagen

Perianth Development in the Basal Monocot Triglochin Maritima (Juncaginaceae)

DOI

10.5642/aliso.20062201.09

First Page

107

Last Page

125

Abstract

Basal monocots exhibit considerable variation in inflorescence and floral structure. In some cases, such as Triglochin maritima, it is not clear whether the lateral and terminal structures of the inflorescence are flowers or pseudanthia, or where the limits between flowers and inflorescence lie. To address these questions, morphological studies were carried out, and the results show that in T. maritima both terminal and lateral structures are flowers, not pseudanthia. The terminal flower of T. maritima develops from the apical inflorescence meristem, suggesting that the apical meristem identity changes from "inflorescence" to "flower" during inflorescence development. In addition, distal flowers of T. maritima are reduced, and there is no distinct flower-subtending bract; instead, the perianth develops unidirectionally, resulting in an abaxial-median bract-like tepa! and bilaterally symmetrical flowers, similar to those of other basal monocots, such as Aponogeton and Acarus. It is possible that the leaf primordium changes its positional homology from "flower-subtending bract" to "tepal." Therefore, in some basal angiosperms with abbreviated development of lateral flowers the demarcation of the flower vs. the inflorescence is ontogenetically ambiguous. In situ hybridization experiments show that a putative ortholog of the B-class gene APETALA3/DEFICIENS is expressed in developing stamens and carpels, and may also be expressed in the shoot axis of the very young inflorescence. This expression pattern seems to be consistent with the gradual transition between inflorescence and flower that was observed morphologically.

Recommended Citation

Buzgo, Matyas; Soltis, Douglas E.; Soltis, Pamela S.; Kim, Sangtae; Ma, Hong; Hauser, Bernard A.; Lebens-Mack, Jim; and Johansen, Bo (2006) "Perianth Development in the Basal Monocot Triglochin Maritima (Juncaginaceae)," Aliso: A Journal of Systematic and Floristic Botany: Vol. 22: Iss. 1, Article 9.
Available at: https://scholarship.claremont.edu/aliso/vol22/iss1/9