J Syst Evol ›› 2009, Vol. 47 ›› Issue (3): 237-244.DOI: 10.1111/j.1759-6831.2009.00023.x

• Research Articles • Previous Articles     Next Articles

Floral organogenesis of Delavaya toxocarpa (Sapindaceae; Sapindales)

1,2,3 Li‐Min CAO 1 Nian‐He XIA*   

  1. 1 (Institute of Economic Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China)
    2 (Department of Life Sciences, Hengyang Normal University, Hengyang 421008, China)
    3 (Graduate University of Chinese Academy of Sciences, Beijing 100049, China) *Author for correspondence. E-mail: nhxia@scib.ac.cn; Tel: 81-020-37252565; Fax: 81-020-37252680.
  • Received:2008-07-03 Published:2009-05-01

Abstract: The floral organogenesis and development of Delavaya toxocarpa Franch. (Sapindaceae) were studied under scanning electron microscope and light microscope to determine its systematic position within Sapindaceae. Flowers arise in terminal thyrses. The sepal primordia initiate in a spiral (2/5) sequence, which are not synchronous. The five petal primordia initiate almost synchronously and alternate with sepal primordia. Eight stamens initiate almost simultaneously and their differentiation precedes that of the petals. The last formed petal and one stamen initiate from a common primordium. Mature stamens curve inwards and cover the ovary in bud. The gynoecium begins as a hemispheric primordium on which two carpellary lobes arise simultaneously. Later in development a single gynocium is formed with two locules and two ovules per locule. Floral morphology suggests a closer affinity with Sapindaceae, although certain features of floral ontogenesis are similar to those observed in certain members of the former Hippocastanaceae, such as Handeliodendron.

Key words: Delavaya toxocarpa Franch, floral organogenesis, Hippocastanaceae, Sapindaceae