Floral Morphology and Development in Quillajaceae and Surianaceae (Fabales), the Species-poor Relatives of Leguminosae and Polygalaceae

Abstract

Differences in the reproductive development and organization of Quillajaceae and Surianaceae cast doubt on their potential sister relationship. Instead, Quillaja resembles Leguminosae in some floral traits, a hypothesis not suggested by molecular-based phylogenies. Despite implicit associations of zygomorphy with species-rich clades and actinomorphy with species-poor families in Fabales, this correlation sometimes fails due to high variation in floral symmetry. Studies considering specific derived clades and reproductive biology could address more precise hypotheses of key innovation and differential diversification in the order.

Towards unlocking the deep nodes of Leguminosae: Floral development and morphology of the enigmatic Duparquetia orchidacea (Leguminosae, Caesalpinioideae)

“…Other Fabales with retarded petal development are Papilionoideae (Fig. 8J–L; see also Tucker, 1987; Klitgaard, 1999; Prenner, 2003, 2004a, d), Quillajaceae and Surianaceae (Bello et al, 2007). In these taxa, the protective function for the inner floral organs is mainly provided by the sepals and/or to a variable degree by the floral prophylls.…”

“…Westerkamp, 1997). Several authors have put forward hypotheses as to why the papilionoid flag blossom became so highly successful in terms of species number (e.g., Westerkamp, 1997; Pennington et al, 2000; Sprent, 2001, 2007; Schrire et al, 2005). Their arguments include (1) adaptation to bees as important pollen vectors and (2) symbiosis with nitrogen‐fixing bacteria, which gave the papilionoids a competitive edge and enabled them to colonize nutrient‐poor soils.…”

Combined phylogenetic analyses reveal interfamilial relationships and patterns of floral evolution in the eudicot order Fabales

“…Tucker, 1984, 1987, 1988, 1989, 1991, 1992, 1996, 1998, 2000a,b, 2001a,b, 2002a,b, 2003a,b, 2006; Tucker and Stirton, 1991; Tucker and Douglas, 1994; Tucker and Kantz, 1997; Prenner and Klitgaard, 2008), but no explicitly phylogenetic studies have extended this research to other families placed in the order Fabales. A broader study integrating recent data for Quillajaceae, Surianaceae, and Polygalaceae (Bello et al., 2007, 2010) has potential to test earlier hypotheses regarding evolutionary trends across the order. Quillajaceae and Surianaceae exhibit numerous differences in the organization of their reproductive whorls, despite their similarity in both inflorescence structure and perianth and gynoecial merosity (Bello et al., 2007).…”

“…A broader study integrating recent data for Quillajaceae, Surianaceae, and Polygalaceae (Bello et al., 2007, 2010) has potential to test earlier hypotheses regarding evolutionary trends across the order. Quillajaceae and Surianaceae exhibit numerous differences in the organization of their reproductive whorls, despite their similarity in both inflorescence structure and perianth and gynoecial merosity (Bello et al., 2007). On the other hand, Leguminosae flowers resemble those of Quillajaceae in several traits (Bello et al., 2007).…”

Perianth evolution in the sandalwood order Santalales

“…Morphological and ontogenetic studies of flowers have proven to be a good complement to molecular data in clarifying organism relationships (e.g., Endress, 2003; Bello et al, 2004, 2007; Ronse de Craene, 2004; Mayr and Weber, 2006; Wanntorp and Ronse De Craene, 2007). Flowers of Santalales vary greatly in morphology and the group encompasses three main types of flowers.…”