Morphological Studies of the Nymphaeaceae Sensu Lato. Xvii. Floral Anatomy of Ondinea Purpurea Subspecies Purpurea (Nymphaeaceae)

Abstract

Classification and phylogeny of the Nymphaeaceae are unresolved. This study provides floral anatomical data that will assist in elucidating generic interrelationships and systematic relationships to other taxa of angiosperms. The floral anatomy of Ondinea purpurea den Hartog subsp. purpurea has been examined utilizing light microscopy. The peduncle possesses stelar vascular bundle complexes and cortical vascular bundles. Cortical bundles terminate within the peduncle. Each bundle complex consists of 2 collateral bundles on the same radius, the inner bundle inverted; 2 protoxylary lacunae occur yet differ in structure and function. Progressing acropetally, the inner xylary lacunae become discrete mesarch strands surrounded centrifugally by a vascular cylinder formed by divisions and anastomosing of the bundle complexes. Together these become the massive receptacular vascular plexus. The plexus provides collateral traces to the floral organs. Each sepal receives 3 traces that separate from the plexus as 1–3 lateral traces. Petals are absent and no vestigial petal traces have been observed. Distally, the plexus forms several large strands of connate gynoecial and androecial traces termed the principal vascular bundles (PVBs). Ventral veins separate from the PVBs and the latter extend acropetally through the outer ovary wall. Branches of the ventrals and PVBs contribute to septal vascular reticula from which each ovule is supplied by one vascular bundle. Each stamen receives 1 trace from branches of the PVBs. The ventrals and PVBs terminate within the carpellary lobes. A comparative anatomical study is offered that supports the inclusion of Ondinea in the Nymphaeaceae sensu stricto.

Developmental morphology of ovules and seeds of Nymphaeales

“…38, 48, 56). Williamson and Moseley (1989) illustrated that Ondinea purpurea also has a cup-shaped outer integument. In Nymphaea alba the outer integument is four or five cells thick (Fig.…”

“…There is a difference in micropyle structure among the Nymphaeales. The micropyle is endostomic or composed of the inner integument in Brasenia, Cabomba (Cabombaceae), Nuphar (Nupharoideae), and Barclaya (Barclayoideae; see Igersheim and Endress, 1998), whereas it is both endostomic and exostomic or composed of the inner and outer integuments in Euryale, Nymphaea, Ondinea (Williamson and Moseley, 1989), and Victoria (Nymphaeoideae). A phylogenetic tree (Les et al, 1999) suggests that the endostomic micropyles are ancestral to the double endo-and exostomic ones in the Nymphaeales.…”

“…Ovules of Nymphaeales are uniformly bitegmic and crassinucellate but vary in their orientation from anatropy to orthotropy (Khanna, 1965(Khanna, , 1967Moseley, 1972;Schneider, 1976Schneider, , 1978Williamson and Moseley, 1989;Johri, Ambegaokar, and Srivastava, 1992;Igersheim and Endress, 1998). Variations within a group may provide useful data for understanding the evolution of ovules in basal angiosperms.…”

A synopsis of Thai Nymphaeaceae

“…Nymphaea, which has traditionally been associated with Victoria and Euryale (Conard 1905), was also placed in a clade with those two genera, although the association was not as strongly supported as the Victoria+Euryale clade; no obvious morphological characters supported the association, but the organization of the gynoecial vascular strands in the three genera share derived features (Weidlich 1980). The next branch of the cladogram was made up of Ondinea, which, however, shared many derived features with Nymphaea in floral structure (Hartog 1970, Williamson and Moseley 1989) and vegetative morphology (Williamson et al 1989), and which in some molecular analysis forms a clade with Nymphaea . The genus Barclaya, which has often been seen as different enough to form its own family (Les 1988), formed the next branch.…”

The unusualOndinea, actually just another Australian water-lily ofNymphaeasubg.Anecphya (Nymphaeaceae)

“…A close relationship of Ondinea to the genus Nymphaea L. was suggested by Hartog (1970) and has been reinforced by studies of several other authors (Kenneally & Schneider 1983;Müller 1970;Schneider 1983;Schneider & Ford 1978;Schneider & al. 1995;Williamson & Moseley 1989).…”