Evolution of reproductive structures in grasses (Poaceae) inferred by sister-group comparison with their putative closest living relatives, Ecdeiocoleaceae

Paula J. Rudall, Wolfgang Stuppy, Jennifer Cunniff, Elizabeth A. Kellogg, Barbara G. Briggs

Research output: Contribution to journalArticlepeer-review

84 Scopus citations

Abstract

Despite much recent activity in the phylogeny and developmental genetics of grasses, the enigmatic homologies of their reproductive structures remain largely unresolved, partly because their highly derived morphology has resulted in a unique associated terminology. Outstanding questions include whether grass lodicules and stamens are derived from a single perianth or stamen whorl, respectively, whether the grass caryopsis is homologous with a nut, and how the scutellum evolved. We investigated the reproductive structures of the putative sister group of grasses, the southwestern Australian family Ecdeiocoleaceae, which includes two genera, Ecdeiocolea and Georgeantha. The zygomorphic arrangement of the four (rather than six) stamens in male flowers of Ecdeiocolea indicates that they may represent three outer stamens plus the adaxial inner stamen. Within Ecdeiocoleaceae, characters such as the highly unusual nucellus structure of Ecdeiocolea are autapomorphic. Sister-group comparisons indicate that some characteristic grass features, notably the scutellum, do not occur in their putative closest relatives and that more data are needed on early-diverging grass genera to resolve these issues. The grass caryopsis could represent one end of a transformation series embodied by the reduced gynoecial structure and indehiscent fruit of other Poales such as Flagellaria, Joinvillea, and Ecdeiocolea.

Original languageEnglish
Pages (from-to)1432-1443
Number of pages12
JournalAmerican Journal of Botany
Volume92
Issue number9
DOIs
StatePublished - Sep 2005

Keywords

  • Caryopsis
  • Ecdeiocolea
  • Flower
  • Georgeantha
  • Grasses
  • Monocots
  • Poaceae
  • Scutellum

Fingerprint

Dive into the research topics of 'Evolution of reproductive structures in grasses (Poaceae) inferred by sister-group comparison with their putative closest living relatives, Ecdeiocoleaceae'. Together they form a unique fingerprint.

Cite this