Pinguicula lavalvae (Lentibulariaceae), a new endemic butterwort from southern Italy diagnosed with the aid of geometric morphometrics

We describe a new butterwort species, Pinguicula lavalvae, endemic to Campania, southern Italy. The new taxon falls within the subgenus Isoloba, section Cardiophyllum, and is related to P. hirtiflora. Distinctive features of the flower shape and size are investigated through classic and modern geometric morphometrics. The new species differs mostly in flower characteristics, with a white corolla lacking a net-shaped pattern of stripes in the palate-like area, smaller and less wide-open corollas, and larger calices.     

Rare species habitat suitability assessment and reliability evaluation of an expert-based model: A case study of the insectivorous plant Pinguicula crystallina Sibth. et Smith subsp. hirtiflora (Ten.) Strid (Lentibulariaceae)

The development of habitat suitability models requires a large amount of data which are rarely available. In this case, researchers need to get information on the ecological features of the studied species, based on the opinion of experts or on the literature, to construct a qualitative model. However, such models cannot be rigorously evaluated, as in most cases absence points are not available. In this paper, we assess the habitat suitability for a vulnerable insectivorous plant, Pinguicula crystallina Sibth. et Smith subsp. hirtiflora (Ten.) Strid (Lentibulariaceae) in the Campania region. Our aim was to develop an expert-based, presence-only model in support of possible conservation actions. Topographic and geological features of this species suggested by the literature were used in our model. Both the Boyce index and field surveys were chosen to evaluate the model's reliability. During field surveys, 31 absence sites and 1 new presence site were identified, and differences between sites with regard to water chemistry and quality were investigated, water being an element in the species habitat. Factors that affect reliability of the model, such as the lack of a large amount of information on the species and the limited spatial resolution of geographical information system data, are discussed.     

Reproductive ecology of three rare North American Pinguicula species

Pinguicula (Lentibulariaceae) is a genus of more than 100 carnivorous plant species. A handful of comprehensive studies have examined the reproductive ecology of these species, mostly in Europe and none in the USA. During 2013–2016 different aspects of the reproductive ecology of P. ionantha, P. lutea and P. planifolia were studied at multiple locations in the Florida Panhandle, USA. All three species are of conservation concern within the study region and some aspects of their reproductive ecology may be contributing to their rarity. For all species, we conducted breeding system studies investigating xenogamy vs. autogamy, self‐incompatibility vs. self‐compatibility, pollen:ovule ratios, flower phenology and longevity, and pollinator visitation, as well as fruit and seed set differences among populations. All three Pinguicula species were determined to be xenogamous and self‐compatible, although the pollen:ovule ratios were extremely low. In addition, these species have floral nastic movements and flower longevity that ranges from 2 to 3 weeks depending on the species. Hymenoptera was identified as the primary group of pollinators visiting all species, although observed visitation events were low. All three Pinguicula species had extremely high levels of fruit set and seed set. Worldwide, Pinguicula species share similar breeding system and reproductive patterns. The rare status of P. ionantha, P. lutea and P. planifolia is more likely due to their ecological requirements, demographics and/or patterns of genetic diversity, than reproduction. This work is among the first and most comprehensive associated with the reproductive ecology of North American Pinguicula.     

Responses of a carnivorous plant to prey and inorganic nutrients in a Mediterranean environment

We have analysed the effect of prey and fertilization by inorganic nutrients on the survival, growth, reproduction (sexual and vegetative) and mucilage secretion of Pinguicula vallisneriifolia (Lentibulariaceae), a carnivorous plant inhabiting rocky substrates of southern Spain. We tested the hypothesis that carnivorous plants are more prey dependent when root access to nutrients is strongly limited by (1) analysing the importance of the carnivorous habit to the fitness of P. vallisneriifolia in its natural rocky habitat, and (2) determining whether the effect of trapped prey varies with soil nutrient levels. Our 2-year experimental results indicated prey to be limiting to P. vallisneriifolia growth on its natural rocky substrate. Animal food supply substantially increased the chance of survival, growth, vegetative propagation, sexual reproductive success and mucilage secretion. The differences between prey levels were more evident at the end of the experiment when all the surviving Prey-exclusion plants had lost weight, and the probability of sexual reproduction and of vegetative propagation by axillary buds had accordingly diminished. Furthermore, there were clear benefits from carnivory at the population level, since both the expected individual life span and the lifetime vegetative and sexual output correlated positively with the quantity of prey trapped. Application of insects to non-fertilized plants stimulated growth, but similar application to fertilized plants grown on a complete nutrient solution failed to enhance growth. There was no obvious benefit from the provision of a balanced mineral nutrient solution (alone or with prey). The greatest absolute growth and sexual and vegetative output resulted from providing a surplus of insects to plants on their natural rocky substrate. The strong dependence of P. vallisneriifolia on prey can therefore be considered a useful preadaptation enabling colonization of rocky substrates. Received: 11 November 1996 / Accepted: 31 March 1997     

Equivalence of three allocation currencies as estimates of reproductive allocation and somatic cost of reproduction in Pinguicula vulgaris

Which is the most appropriate currency (biomass, energy, water, or some mineral nutrient) for expressing resource allocation in plants has been repeatedly discussed. Researchers need to assess to which extent interindividual, interpopulational, or interspecific comparisons of resource allocation could be affected by the allocation currency chosen. The "currency issue" is relevant to at least three related aspects of resource allocation to reproduction: (a) reproductive allocation (RA), (b) size-dependence of reproductive allocation, and (c) somatic cost of reproduction (SCR). Empirical tests have mostly dealt with the first aspect only. We examined the equivalence of estimates for the three aspects above across three different allocation currencies (dry mass, N, P) in 11 populations of PINGUICULA VULGARIS. For RA we studied the equivalence of allocation currencies at three scales: among individuals of the same population, between populations of the same species, and among species. Equivalence of currencies in the ranking of RA for individuals within populations was high ( RS >/= 0.43) and did not strongly decrease when comparing populations or species. Excepting for size-dependence of RA, ranking of RA, or SCR between populations was equivalent for biomass and N, but not for P. Our study gives two positive guidelines for empirical plant reproductive ecologists facing the "currency issue": (1) become increasingly concerned about the "currency issue" as you increase the scale of your comparison from individuals to populations to species, and (2) avoid estimating allocation in redundant currencies (biomass and N in our case) and choose preferentially "complementary" currencies that provide a broader view of allocation patterns (biomass and P in our case).     

Morphology and nrITS phylogeny of the genus Pinguicula L. (Lentibulariaceae), with special attention to embryo evolution

The genus Pinguicula (Lentibulariaceae) is unusual within the dicot order Lamiales because of the occurrence of both embryos with two cotyledons and those with just one cotyledon. In order to elucidate the infrageneric relationships and the evolutionary history of the embryo, we analysed (1) the internal transcribed spacers ITS1 and ITS2 of the nuclear ribosomal DNA (nrITS) of 29 Old and New World taxa of Pinguicula, and (2) the morphological and anatomical characters of the seeds. We suggest that the cotyledon number and spermoderm structure were quite unstable in the evolution of Pinguicula. Although basal nodes of the nrITS tree are sensitive to taxon sampling, all tree topologies found in this study imply homoplasy in the cotyledon number.     

Smallest angiosperm genomes found in lentibulariaceae, with chromosomes of bacterial size

Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosperms, with the smallest established 1C-value of 157 Mbp recorded in Arabidopsis thaliana. In the highly specialized carnivorous family Lentibulariaceae now three taxa have been found that exhibit significantly lower values: Genlisea margaretae with 63 Mbp, G. aurea with 64 Mbp, and Utricularia gibba with 88 Mbp. The smallest mitotic anaphase chromatids in G. aurea have 2.1 Mbp and are thus of bacterial size (NB: E. coli has ca. 4 Mbp). Several Utricularia species range somewhat lower than A. thaliana or are similar in genome size. The highest 1C-value known from species of Lentibulariaceae was found in Genlisea hispidula with 1510 Mbp, and results in about 24-fold variation for Genlisea and the Lentibulariaceae. Taking into account these new measurements, genome size variation in angiosperms is now almost 2000-fold. Genlisea and Utricularia are plants with terminal positions in the phylogeny of the eudicots, so that the findings are relevant for the understanding of genome miniaturization. Moreover, the Genlisea-Utricularia clade exhibits one of the highest mutational rates in several genomic regions in angiosperms, what may be linked to specialized patterns of genome evolution. Ultrasmall genomes have not been found in Pinguicula, which is the sister group of the Genlisea-Utricularia clade, and which does not show accelerated mutational rates. C-values in Pinguicula varied only 1.7-fold from 487 to 829 Mbp.     

Sympodial construction of Fibonacci-type leaf rosettes in Pinguicula moranensis (Lentibulariaceae)

BACKGROUND AND AIMS: The leaf rosettes of the carnivorous Pinguicula moranensis follow a spiral phyllotaxis approaching a Fibonacci pattern while the stalked flowers arise from extra-axillary sites between the leaves. The organization of this rosette has been discussed by various authors, with various results. The aim of the present study was to clarify the development of the flowering rosettes of this species. METHODS: The formation of the rosettes is shown with the aid of scanning electron microscopy. KEY RESULTS AND CONCLUSIONS: The scanning electron micrographs show that each flower terminates an article (sympodial unit). The leaves of consecutive articles of such sympodially constructed rosettes are arranged along a spiral Fibonacci pattern (with divergence angles around 137 degrees). This results from homodromy of leaf initiation in consecutive articles with the first leaf (prophyll) of a new article inserted in an obliquely transverse position next to the floral scape that terminates the former article. Sympodial construction of flowering shoots and leaf rosettes is also known from Aloe, Gunnera and Philodendron. As a by-product of this study, the unidirectional development of the Pinguicula flower is confirmed and discussed.