Developmental and Structural Section
Angell, Amy C. , Owen, T. Page .
Pistillate Flower Development in Poinsettia (Euphorbia pulcherrima).
The Euphorbiaceae has been studied extensively doe to the laticifers, latex, and reduced inflorescence that are structural feature defining this family. The economically important poinsettia, Euphorbia pulcherrima, exhibits common features of the genera, but has been studied on intermittently. This anatomical study examined cyathium and pistillate flower development, early embryo development, and ovary wall laticifer and vascular growth. Epidermal cells of the cyathium were rounded and smooth, while those on the large extrafloral nectary were rectangular and in parallel bands. Trichomes were present at the cyathium apex. The ovary was trilocular and centrally axile. Ovules lacked a nucellar beak, were anatropous with obturator tissue developing to the nucellus, and the embryo sac showed Polygonum-type development. A hypostase developed at the chalazal region. Ovary wall non-articulated laticifers developed near the epidermis, while the vasculature formed on the other side; each thoroughly permeating the wall tissue by later phases. The pistillate flowers demonstrated developmental growth consistent with other Euphorbiaceae, with the exception of the nucellar beak being absent. The trichome network may serve to help facilitate pollination, while the development and location of the ovary wall laticifers suggests a function to deter herbivory. ACA was supported by the Keck Undergraduate Science Program at Connecticut College; current address: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775
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1 - Connecticut College, Department of Botany, New London, CT, 06320, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM