Biological Flora of Central Europe: Baldellia ranunculoides (Alismataceae)

Abstract

Baldellia ranunculoides (L.) Parl. (Alismataceae) is a taxonomically problematic aquatic plant with an historically illdefined distribution and global conservation status. This paper finds morphological, ecological and molecular evidence for two distinct taxa, probably best described as subspecies: (1) B. ranunculoides subsp. ranunculoides and (2) B. ranunculoides subsp. repens and provides detailed distribution data on their overlapping range, in different habitats, across the cool, high rainfall areas of western Europe and west Mediterranean. The two subspecies are amongst the relatively large number of threatened European and north Africa aquatic plants and this paper provides a systematic review of their relative conservation pressures and management needs, with particular emphasis on the status of both taxa in central Europe. Other observations indicate probable evolutionary relationships within B. ranunculoides s.l. and its associated taxa and the review points out where these and other research topics could potentially be pursued.

Morpho-environmental characterization of the genusBaldelliaParl. (Alismataceae) in the Iberian Peninsula, Balearic islands and North Morocco

“…The marked robustness and size were the main features suggesting the possibility of hybridisation with A. plantago-aquatica (Pau 1924;Molina Abril et al 1994). Recently, another hybrid, in this case from Ireland, has been reported (Kozlowski et al 2008).…”

“…Two decades later, Lamarck (1778) classified this species as A. repens, based on its capacity to develop pseudowhorl proliferations. In fact, the presence of these proliferations has been emphasised by numerous authors over the years (Gmelin 1796 Fiori & Paoletti 1908;Pitard 1912;Dandy 1980;Amaral Franco & Rocha Afonso 1994;Stace 1995;Kozlowski et al 2008;Talavera et al 2008).…”

“…The complexity of Baldellia classification has been clearly emphasised by Kozlowski et al (2008), Kozlowski and Matthies (2009) and Kozlowski and Vallelian (2009), who analysed the genus as regards several ecological and biological aspects; contributions on morpho-reproductive or biogeographical aspects where also presented by Charlton (1973) and Vuille (1998). The existence or absence of proliferous stolons, and the development of either large or small flowers have been often considered as distinctive characters.…”

“…ranunculoides. The shape of the leaves (obtuse for B. alpestris and acuminate for the others, as a response to environmental conditions, or ''floating leaves'' according to Kozlowski et al 2008), the size of the anthers (usually less than 1 mm for B. alpestris and B. ranunculoides, and 1-2 mm for B. repens), the number of flowers and fruits (usually less than five for B. alpestris and B. repens subsp. cavanillesia, and five or more for the other species) and the surface of the fruits (smooth in B. alpestris, and with prominent ridges in the other taxa) represent the main morphological differences.…”

“…The phytosociological studies, which included Baldellia (Velayos et al 1984;Carretero 1989;Velayos et al 1989;Ursú a Sesma & Báscones Carretero 2000;Molina Abril 2001;Lence et al 2002;Honrado 2003;Ortega et al 2007;Dias Pereira & Silva Neto 2008;Silva et al 2008;Silva 2009;Silva et al 2009 Kozlowski et al 2008), with occurrence in dense or scarce amphibious swards or in weed communities in rice fields. Baldellia spp.…”