@article {54, title = {Floral structure and development of Acoraceae and its systematic relationships with basal angiosperms}, journal = {International Journal of Plant Sciences}, volume = {161}, year = {2000}, pages = {23-41}, abstract = {

Flower development and anatomy of Acorus calamus and flower anatomy of A. gramineus were studied. Findings were compared with published reports on paleoherbs. Important developmental features include an abaxially median tepal that is initiated first and is similar to a flower-subtending bract and unidirectional flower development with an inversion of organ initiation sequence in the second tepal whorl. The mature gynoecium is largely synascidiate, but early development of carpels is plicate, and the apocarpous portion persists up to anthesis. The carpels form dorsal bulges on the style, enclosing longitudinal intercarpellary slits. The dominance of the synascidiate portion and the apical position of the placenta result from a late and distinct basal elongation of the gynoecium. Stigma, pollen transmitting tract, and ovary are filled with secretion. Secretory papillae are present from the stigma to the placenta; papillae also occur on the rims of the integuments of the ovules. In the uppermost part of the inflorescence, the adaxial floral sectors are reduced in number and structure, and at the apex of the inflorescence, a peloria-like structure is formed. Developmental and morphological similarities seem to be closer between Acorus and Piperales than between Acorus and other magnoliids.

}, keywords = {Acoraceae, complex organs, flower development, monocots, paleoherbs, Piperales}, url = {http://www.jstor.org/stable/10.1086/314241}, author = {Buzgo, Matyas and Endress, Peter K.} } @article {57, title = {Perianth development in the basal monocot Triglochin maritima (Juncaginaceae)}, journal = {Aliso}, volume = {22}, year = {2006}, pages = {107-125}, 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 tepal and bilaterally symmetrical flowers, similar to those of other basal monocots, such as Aponogeton and Acorus. 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.

}, keywords = {APETALA3, basal angiosperms, fading borders, gene expression pattern, Juncaginaceae, MADS-box gene, monocots, organ identity, Triglochin}, url = {http://curis.ku.dk/ws/files/13860089/PERIANTH_DEVELOPMENT_IN_THE_BASAL_MONOCOT.pdf}, author = {Buzgo, Matyas and Soltis, Douglas E. and Soltis, Pamela S. and Kim, Sangtae and Ma, Hong and Hauser, Bernard A. and Leebens-Mack, Jim and Johansen, Bo} } @article {31, title = {Early Cretaceous lineages of monocot flowering plants}, journal = {Proc. Natl. Acad. Sci. USAProc. Natl. Acad. Sci. USA}, volume = {97}, number = {9}, year = {2000}, pages = {4707-4711}, keywords = {Cretaceous, fossils, monocots}, author = {Bremer, Kare} }