Topic
Spigelia
About: Spigelia is a research topic. Over the lifetime, 22 publications have been published within this topic receiving 64 citations.
Papers
TL;DR: It is hypothesize that in the autogamous Spigelia anthelmia this event selects for the fittest male gametophytes by competition of the pollen tubes counteracting possible inbreeding depression caused by continual self-fertilisation.
Abstract: In the genus Spigelia (Spigeliaceae, Gentianales) we report for the first time the phenomenon of secondary pollen presentation. In Spigelia anthelmia, S. marilandica, and S. splen-dens a deposition mechanism as found in some members of the Rubiaceae could be observed in living material. In Spigelia longi-flora, S. sellowiana, and S. speciosa we can expect this mechanism from observation of pollen load on the style seen in herbarium material (K). Some time after anthesis the pistil shows curious behaviour in that the upper part of the style detaches from the lower part at a histologically differentiated area. In the allo-gamous Spigelia splendens this may promote prezygotic selection. We hypothesize that in the autogamous Spigelia anthelmia this event selects for the fittest male gametophytes by competition of the pollen tubes counteracting possible inbreeding depression caused by continual self-fertilisation. The fastest growing pollen tubes, which reach the lower style before detaching, are able to penetrate the ovules. Many germinated pollen grains whose pollen tubes grow slowly remain on the upper detached part of the style. Obviously Spigelia onthelmia accepts a lower seed set in favour of increased fitness of the progeny. Within the genus Spigelia, distributed in tropical and subtropical America, Spigelia anthelmia is the only species found on other continents. It is a successful pioneer plant and weed in tropical Africa and Asia, perhaps due to its “strategy of controlled autogamy”.
18 citations
TL;DR: A phylogenetic parsimony and Bayesian analysis of ITS sequences from 15 Spigelia species plus 17 outgroups in Loganiaceae confirms its independent taxonomic status: on the basis of sequence similarity and phylogenetic topology it is phylogenetically distinct from all Spigilia species sequenced so far.
Abstract: A new species of Spigelia L. (Loganiaceae), Spigelia genuflexa Popovkin & Struwe, sp. n., from the Atlantic forest of northeastern Bahia, Brazil, is described, being the first reported geocarpic species in the family. During fruit maturation, the basal infructescences bend down towards the ground, depositing the fruit on the surface (and burying it in soft kinds of ground cover, e.g., moss), whereas the upper ones do so slightly but noticeably. The species is a short-lived annual apparently restricted to sandy-soil habitat of the Atlantic forest of northeastern Bahia, with variable and heterogeneous microenvironment and is known from only two restricted localities. A short review of amphi- and geocarpic species is provided. A discussion of comparative morphology within Spigelia with regards to dwarfism, indumentum, and annual habit is included. A phylogenetic parsimony and Bayesian analysis of ITS sequences from 15 Spigelia species plus 17 outgroups in Loganiaceae confirms its independent taxonomic status: on the basis of sequence similarity and phylogenetic topology it is phylogenetically distinct from all Spigelia species sequenced so far.
16 citations
TL;DR: Two new species of Spigelia (Loganiaceae) from the states of Guerrero and Estado de Mexico are described, which places the country as the second highest area of diversity after Brazil.
Abstract: Two new species of Spigelia (Loganiaceae) from the states of Guerrero and Estado de Mexico are described here. This species represents a case of convergence with a species native to South America, Spigelia nicotianiiflora. With this addition, Mexico reaches a total of 22 species of the genus, of which more than 50% are endemic or microendemic. This places the country as the second highest area of diversity after Brazil. A map of the distribution in Mexico and a dichotomous key for Spigelia species with white corollas are included.
10 citations
TL;DR: In this article, two volatile alkaloids have been identified as isoquinoline and an iridoid compound of the actinidine type, which are involved in the cardiotonic activity of the plant.
Abstract: From the upper parts of SPIGELIA ANTHELMIA L. besides some widely distributed phenolcarboxylic acids and flavonoids two volatile alkaloids have been isolated and identified as isoquinoline and an iridoid compound of the actinidine type. In the water extract choline, benzoylcholine and 3,3-dimethyl-acryloylcholine could be identified. Preliminary pharmacological investigations revealed that the alkaloids are involved in the cardiotonic activity of the plant.
9 citations
TL;DR: A new species of Spigelia endemic to Guerrero, Mexico, is described and illustrated and its distribution map and conservation status recommendation for the new species are provided, as well as a key to the species known from Guerrero.
Abstract: A new species of Spigelia endemic to Guerrero, Mexico, is described and illustrated. Spigelia guerrerensis sp. nov. can be separated from all known species of the genus by its infundibuliform white corollas sometimes tinged with purple at the lobe margins and in the base of the throat, apically hirsutulose fruits, and its restriction to the mountain system of northeastern Guerrero. In addition, we provide a distribution map and conservation status recommendation for the new species, as well as a key to the species of Spigelia known from Guerrero. Including this new addition, 17 species are recognized in Mexico, making it one of the hotspots of the genus.
7 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2019 | 2 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 2 |
| 2015 | 1 |