Neotropical nymphoides (Menyanthaceae): Meso-American and west indian species
TL;DR: The Mexican and Guatemalan Nymphoides fallax, described in this paper, differs from N. indica in having winged yellow petals with a stipitate basal tuft of hairs, consistently yellow anthers, larger seeds, and higher altitudinal occurrence.
Abstract: Studies ofNymphoides (Menyanthaceae) in Mexico, Central America, and the West Indies indicate that three species are present in this region, all of which are members of theNymphoides indica complex. White-flowered plants of Meso-America, the Antilles, and South America traditionally have been referred toN. humboldtiana but are identical to the otherwise Old WorldN. indica and must be called by the latter name. The Mexican and GuatemalanNymphoides fallax, described in this paper, differs fromN. indica in having winged yellow petals with a stipitate basal tuft of hairs, consistently yellow anthers, larger seeds, and higher altitudinal occurrence. Yellow-flowered plants of the Bahamas and Cuba are considered to represent a third species,N. grayana, which resembles plants of southern Brazil and southern Africa in flower color and morphology. However, because of the geographic distribution and unique ultraviolet-light emittance characters ofN. grayana and the still uncertain relationships of the Brazilian and African populations, this third taxon is provisionally retained at the specific level pending further study of those populations.
Citations
More filters
TL;DR: A phylogenetic study of 31 Nymphoides species, including all species native to Australia, to evaluate interspecific relationships and to infer the evolution of heterostyly and inflorescence architecture indicated that the expanded inflorescence morphology found in several Australian and tropical Asian NymphOides species represents the ancestral condition for the genus.
Abstract: The cosmopolitan genus Nymphoides contains approximately 50 species that vary considerably in growth habit, inflorescence architecture, and in vegetative, floral, and seed morphology We undertook a phylogenetic study of 31 Nymphoides species, including all species native to Australia, to evaluate interspecific relationships and to infer the evolution of heterostyly and inflorescence architecture. Phylogenetic analysis of morphological data resolved several clades of species, but with poor branch support. Molecular data from nuclear (ITS) and plastid (matK/trnK) DNA sequences were significantly incongruent regarding the phylogenetic placement of many clades and species. Two major clades were resolved consistently: a clade sister to N. minima and the clade comprising these two lineages. Incongruent phylogenetic placements of several Nymphoides species were attributed to putative ancestral hybridization that produced conflicting phylogenetic signals between the maternally inherited cpDNA and the biparentally inherited nuclear DNA (subsequently homogenized to a single allelic variant by concerted evolution). Ancestral character state reconstruction indicated that the first Nymphoides species were heterostylous, followed by four independent transitions to homostyly and up to four subsequent reversions back to heterostyly. The evolutionary history of dioecy and gynodioecy could not be ascertained with confidence, owing to incomplete taxon sampling, poor resolution of crown clades, and incongruence between nuclear and plastid sequence data. Ancestral state reconstruction also indicated that the expanded inflorescence morphology found in several Australian and tropical Asian Nymphoides species represents the ancestral condition for the genus, from which a condensed morphology (found in most other Nymphoides species worldwide) evolved independently at least twice.
44 citations
Cites background from "Neotropical nymphoides (Menyanthace..."
...In Nymphoides ( x = 9), chromosome numbers are known for relatively few species, although multiple diploid (2 n = 18), tetraploid (2 n = 36), and hexaploid (2 n = 54) species have been reported for the genus ( Ornduff 1970 ; Li et al. 2002 )....
[...]
...Although the two taxa allegedly are indistinguishable morphologically ( Ornduff 1969 ), they differ at least chromosomally, with the former being tetraploid and the latter diploid ( Ornduff 1970 ; Appendix 1)....
[...]
TL;DR: Chromosome counts indicate that x = 9 in the aquatic genus Nymphoides (Menyanthaceae), and self-incompatible distyly, dioecism, and homostyly are present in the genus.
Abstract: Chromosome counts indicate that x = 9 in the aquatic genus Nymphoides (Menyanthaceae). New World species are tetraploid, but diploid species as well as tetraploid ones occur in the Old World. The pan-tropical N. indica is tetraploid in the New World and diploid in the Old World, but no consistent morphological characters have been found that separate these chromosomal races. The Eurasian N. peltata is hexaploid. Self-incompatible distyly, dioecism, and homostyly are present in the genus. The latter two breeding systems are believed to be derived from distyly. The Colombian N. flaccida seemingly occurs in the long-styled form only and because of its self-incompatibility may reproduce exclusively by vegetative means.
36 citations
TL;DR: A phylogenetic analysis of Menyanthaceae indicates that the genera Menyanthes, Nephrophyllidium, and Nymphoides should be retained as circumscribed, with the exception that NymphOides exigua should be restored to Villarsia.
Abstract: Menyanthaceae consist of five genera of aquatic and wetland plants distributed worldwide. The three monotypic genera (Liparophyllum, Menyanthes, and Nephrophyllidium) are clearly differentiated morphologically, but the two larger genera (Nymphoides and Villarsia) contain several taxa of uncertain affinity. We undertook a phylogenetic analysis, using a combination of morphological and molecular data, to resolve relationships among species and to evaluate the current circumscription of genera. DNA sequence data for nuclear (ITS) and chloroplast (rbcL and trnK/matK) gene regions were largely congruent (by partition-homogeneity test), and a combined data phylogeny revealed several strongly supported relationships. Analyses using asterid outgroup taxa supported the monophyly of Menyanthaceae. Menyanthes trifoliata and Nephrophyllidium crista-galli comprised a clade sister to the remainder of the family. Species of Nymphoides, except N. exigua, resolved to a single, deeply-nested clade, indicating that...
36 citations
TL;DR: A correlation between plant form and type of corolla margin supports the surface-tension hypothesis, and the membranous and ruffled corollar margins were found in species whose flowers had less risk of contacting the water's surface.
Abstract: Attractive features of flowers are adaptations for biotic interactions, and a few floral adaptations are for interactions with the physical environment. Marginal corollar appendages of Nymphoides (Menyanthaceae) can be membranous, a fringe of trichomes, or a ruffle. Although clearly enhancing display, a fringed corollar margin might function by generating a significant upward force through surface tension, an interaction adaptive in an aquatic environment. The force needed to dunk flowers with an intact corollar fringe and those whose fringe had been trimmed showed a significant difference. The fringe added a mean of 10.4% to the floral mass, but the upward force generated increased by nearly 50%, a significant difference from the predicted change based upon buoyancy alone. A correlation between plant form and type of corolla margin supports the surface-tension hypothesis. The membranous and ruffled corollar margins were found in species whose flowers had less risk of contacting the water's surface.
19 citations
TL;DR: Flavonoid data support the view, based upon morphology, that the South African Villarsia capensis is more closely related to eastern AustralianVillarsia species than to Western Australian ones that are geographically closer.
Abstract: This paper describes our study of the flavonoid chemistry of the Menyanthaceae, which included Menyanthes, Fauria (= Nephrophyllidium), Liparophyllum (all monotypic), nine species of Nymphoides, and 1 1 species of Villarsia. The flavonoid profiles are based upon kaempferol, 7-O-methylkaempferol, quercetin, 7-0-methylquercetin, isorhamnetin, 3,7-di-O-methylquercetin, and 7,3'-di-O-methylquercetin, although not all taxa exhibit all of these aglycones. These compounds occur as a complex mixture of 3-0-mono- and 3-0-diglycosides; 4'-O-glucosides were restricted to four species of Nymphoides. Some acylated glycosides were also observed. The presence of flavonols and absence of both C-glycosylflavones and xanthones set the Menyanthaceae apart from the Gentianaceae, the family with which it is most often allied. Flavonoid data do not allow assignment of the Menyanthaceae with surety to either the Gentianales or Solanales. The flavonoid profiles of Liparophyllum and Fauria are unique within the family and do not support a close affinity of the latter genus to Menyanthes. A close relationship between Nymphoides and Villarsia, suggested on morphological grounds, is supported by the flavonoid data. Flavonoids support the view, based upon morphology, that the South African Villarsia capensis is more closely related to eastern Australian Villarsia species than to Western Australian ones that are geographically closer. Segregation of Nymphoides fallax from other Meso-American and Caribbean taxa is supported by the flavonoid data. Flavonoid data also support the view that N. indica is a circumtropical taxon not deserving separate species status in the New World.
18 citations
References
More filters
Book•
01 Jan 1864
TL;DR: Flora of the British West Indian Islands as discussed by the authors, Flora of British West Indies, Flora OF The British West India Islands,Flora OF THE British WIndies.
Abstract: Flora of the British West Indian Islands , Flora of the British West Indian Islands , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
163 citations
"Neotropical nymphoides (Menyanthace..." refers background in this paper
...The whiteflowered plants have been referred to N. humboldtiana (cf. Grisebach, 1864; Maz6, 1892; Heckel, 1896; Urban, 1910, 1921; Barker & Dardeau, 1930; Stahl, 1936; Moscosco, 1943; Williams & Williams, 1951), but like the white-flowered MesoAmerican populations, these cannot be distinguished from…...
[...]
TL;DR: There is evidence that in at least two angiosperm families (Rubiaceae and Menyanthaceae) heterostyly has been replaced by an even more effective outbreeding mechanism in the form of dioecism, which seems to have been previously unrecorded for this family.
Abstract: Heterostyly refers to a relatively rare combination of morphological, physiological, and genetic mechanisms which promotes outbreeding in certain angiosperms. Under conditions where the selective forces favoring this degree of outbreeding are reduced or removed, one or all of the components of this character complex may break down with the result that inbreeding partially or almost wholly replaces outbreeding. There are numerous examples of such a breakdown of heterostyly in the direction of increased selfpollination in taxa belonging to various plant families. Because the complex combination of floral mechanisms and incompatibility characteristic of heterostylous plants is apparently generally effective in promoting outbreeding, the breakdown of heterostyly in the opposite direction, namely in the direction of increased outbreeding, is uncommon. Nevertheless, there is evidence that in at least two angiosperm families (Rubiaceae and Menyanthaceae) heterostyly has been replaced by an even more effective outbreeding mechanism in the form of dioecism. The purpose of this paper is to discuss the breeding systems of various distylous and dioecious members of the menyanthaceous genus Nymphoides and to present an account of the probable origin of dioecism in this genus. Nymphoides has an almost cosmopolitan distribution, occurring primarily in tropical and subtropical areas but also in certain temperate regions of both the Northern and Southern hemispheres. The plants are aquatic or subaquatic, and are typically limited to the still water of ponds, lakes, and slow-moving streams. In all Nymphoides species examined, maturation of floral buds is underwater. In the morning of anthesis the buds are raised above the water level and flowering occurs. After a few hours the corolla withers, the pedicel deflects, and subsequent fruit development is underwater. DIOECIOUS SPECIES Dimorphic heterostyly is widespread in the genera of Menyanthaceae, but dioecism seems to have been previously unrecorded for this family (Gilg, 1895). The two species of Nymphoides indigenous to the United States are dioecious. These are N. cordata, an inhabitant of ponds and slow streams ranging from eastern Canada to Florida and Louisiana, and N. aquatica, a species of similar habitats ranging from New Jersey to Florida and Texas. The two species are closely related but are distinguishable on foliar, root, and floral characters. The floral morphology of these dioecious species is very similar. The ovary of pistillate flowers is capped by a short style and a large fleshy stigma. The vestigial stamens of such flowers are relatively large and conspicuous, consisting of white anthers and short filaments. Alternating with these non-polliniferous stamens are staminode-like clusters of yellow trichomes (Fig. 1). The yellow corolla bases and additional tufts of yellow trichomes at the basal petal margins provide additional color contrast to the white corollas. Staminate flowers have well-developed stamens that produce copious pollen. The pistil of such flowers essentially lacks a style or stigma, but the ovary is large and is filled with ovules of approximately the size and number of those produced by pistillate flowers (Fig. 1). Nevertheless, despite repeated polli-
106 citations