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Left upper: Flower of Utricularia stygia growing in a floating aquarium in the outdoor culture of the Institute of Botany at Třeboň, Czech Republic; May 2005. The plants originate from Švarcenberk. Right upper: Scanned shoots of U. stygia from Hliníř; May 2000. Left bottom: Flowering U. stygia in a very dense stand at Hliníř; June 2003. Photo by J. Flísek. Right bottom: Scanned flower of U. stygia from the outdoor culture; August 2003. The plants originate from Švarcenberk. Note reddish tinge of the corolla and relatively long spur. The other images by L. Adamec.
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Utricularia ochroleuca R. Hartm. is an amphibious/aquatic carnivorous plant occurring relatively rarely throughout Europe and North America in peat bogs and shallow standing dystrophic waters. This species rarely flowers, is sterile, and is possibly of hybridogenic origin (i.e. U. minor × U. intermedia).
Contexts in source publication
Context 1
... (1988) split this taxon into two species, U. ochroleuca s. str. and U. stygia Thor (see Figure 1), on the basis of minor differences in corolla morphology, the number of leaf teeth tipped with bristles, and, espe- cially, in the structural details of the quadrifid (i.e. four-armed) ×-shaped glands (hairs) in their carnivorous traps. ...
Context 2
... some investigated sites (Hliníř and Vizír) at which we had determined U. stygia using the angles of the arms, we later found flowers which corresponded to the taxon of U. stygia. They reminded those in the Institute's culture (see Figure 1, collected from Švarcenberk) and were dark yellow with red ribs and 4-5 mm long spur. ...
Context 3
... (1988) split this taxon into two species, U. ochroleuca s. str. and U. stygia Thor (see Figure 1), on the basis of minor differences in corolla morphology, the number of leaf teeth tipped with bristles, and, especially, in the structural details of the quadrifid (i.e. four-armed) ×-shaped glands (hairs) in their carnivorous traps. ...
Context 4
... some investigated sites (Hliníř and Vizír) at which we had determined U. stygia using the angles of the arms, we later found flowers which corresponded to the taxon of U. stygia. They reminded those in the Institute's culture (see Figure 1, collected from Švarcenberk) and were dark yellow with red ribs and 4-5 mm long spur. ...
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... Therefore, the shape of the quadrifids can help distinguish between some species [39]. However, it should be remembered that, within a population, a single individual, or even a trap, there can be differences in the shape of the trichomes (in the angle of the arms) [40,41]. Yang et al. [42] proposed that in the genus Utricularia, there is an evolutionary trend of reduction in the arm number (in the sense of reducing the number of terminal cells) of the internal trap's trichomes, and the occurrence of quadrifids and bifids is an ancestral characteristic. ...
Species in the genus Utricularia are carnivorous plants that prey on invertebrates using traps of leaf origin. The traps are equipped with numerous different glandular trichomes. Trichomes (quadrifids) produce digestive enzymes and absorb the products of prey digestion. The main aim of this study was to determine whether arabinogalactan proteins (AGPs) occur in the cell wall ingrowths in the quadrifid cells. Antibodies (JIM8, JIM13, JIM14, MAC207, and JIM4) that act against various groups of AGPs were used. AGP localization was determined using immunohistochemistry techniques and immunogold labeling. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of the pedestal cell, which may be related to the fact that AGPs regulate the formation of wall ingrowths but also, due to the patterning of the cell wall structure, affect symplastic transport. The presence of AGPs in the cell wall of terminal cells may be related to the presence of wall ingrowths, but processes also involve vesicle trafficking and membrane recycling, in which these proteins participate.
... Extensive morphological studies of European and North American populations of U. ochroleuca and U. stygia revealed high variability of diagnostic vegetative characters (including the main onethe shape of quadrifid glands inside the traps) and methodological problems of their recording (reviewed in . Thus, the treatment of U. stygia as a separate species (Thor, 1988) is still to be evaluated on the area-wide scale (Płachno and Adamec, 2007;Crow, 2015). ...
... shape of quadrifid glands inside traps) is well-known (e.g. Płachno and Adamec, 2007;Astuti and Peruzzi, 2018;summarized in Adamec, 2020) and was demonstrated by us within a single population of U. ochroleuca s.str., which excludes ecological variation. To our opinion, the suggested threshold value (mean angle between the short arms for U. ochroleuca s. str. is > 120 • at least in 10 % of glands: Płachno and Adamec, 2007) is artificial and not applicable in routine biodiversity studies. ...
... Płachno and Adamec, 2007;Astuti and Peruzzi, 2018;summarized in Adamec, 2020) and was demonstrated by us within a single population of U. ochroleuca s.str., which excludes ecological variation. To our opinion, the suggested threshold value (mean angle between the short arms for U. ochroleuca s. str. is > 120 • at least in 10 % of glands: Płachno and Adamec, 2007) is artificial and not applicable in routine biodiversity studies. Plants with both types of quadrifid glands occurring inside traps in comparable proportions (that we refer to as intermediate U. ochroleuca s.l.) should be formally classified as U. ochroleuca s.str. ...
Most of Utricularia taxa in temperate Eurasia are poorly distinguished by vegetative characters, while flowering is rare in some of them. Thus, we aimed to clarify the taxonomy and distribution of temperate Eurasian Utricularia. We supplemented the existing results of intensive morphological and genetic studies of Utricularia mainly from West and Central Europe with our data from East Europe and North Asia. We combined molecular barcoding (nuclear ITS and plastid rps16 regions) and fingerprinting (ISSR) techniques (74 collection localities) with morphological analysis of herbarium collections (more than 1800 specimens from 16 herbaria) and numerous natural populations with a special focus on hardly accessible Siberian and Far Eastern regions of Russia.
We demonstrated that temperate Eurasian Utricularia taxa could be easily discriminated with barcoding approach if the hybridization is taken into account. Genetic and morphological variation of U. macrorhiza in comparison with U. vulgaris supported the treatment of the former as a separate species. We have revealed U. tenuicaulis previously treated as fertile lineage of U. australis and its sterile hybrid with U. macrorhiza (U. × japonica) in the Russian Far East and the latter additionally in southwestern East Siberia, outside their known distribution. For the first time we evidenced hybridization between U. tenuicaulis and U. vulgaris. The sterile hybrid (U. × neglecta) is widely distributed in Europe and West Siberia. In the Northern Hemisphere, plants initially referred to as sterile U. australis represent in fact U. × japonica and U. × neglecta, and the name U. australis should not be applied to any of them. Utricularia ochroleuca and U. stygia represent a complex of sterile forms with continuous morphological variation (U. × ochroleuca) originated from hybridization between U. intermedia and U. minor. Almost forgotten Japanese species U. multispinosa appeared to be sister to all temperate Eurasian species, and it was revealed for the first time in the southern Russian Far East.We have refined the distributions of Utricularia species in East Europe and North Asia and have shown that extant areas of U. macrorhiza and U. vulgaris are explained by the temperature regime – an important insight in context of global climate change.
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... vulgaris L., U. australis R. Brown, U. minor, U. intermedia, U. ochroleuca, and the newly described U. stygia Thor (which is very similar to U. ochroleuca)-based only on quadrifids. Drawing from Thor's study and citing the rarity of flowering in both U. stygia and U. ochroleuca as well as the unreliability of the number of teeth along the leaf segments as diagnostic, Plachno and Adamec (2007) embarked on a study of the differentiation of the two taxa based on the quadrifid glands for plants of the Czech Republic. They concluded that the only statistically reliable criterion distinguishing these two species in the sterile state is the measurement of the angle between the shorter arms. ...
... They concluded that the only statistically reliable criterion distinguishing these two species in the sterile state is the measurement of the angle between the shorter arms. Crow (2015a) applied this information from Thor (1988) and from Plachno and Adamec (2007) to the problem of distinguishing U. ochroleuca by the morphology of the quadrifids, especially focusing on measurements of hundreds of quadrifids of U. ochroleuca, U. intermedia, U. minor, U. vulgaris subsp. macrorhiza, as well as to determine whether U. stygia occurs in North America. ...
Noteworthy Collection: The first record of Utricularia ochroleuca R. W. Hartman (Yellowish-white Bladderwort or Northern Bladderwort) in Michigan.
... Particular attention in applying the barcoding technique should be paid in the case of plants showing high mutational rates and clonal reproduction, such as species of the genus Utricularia L. (bladderworts). Bladderworts also epitomize the peculiar so-called "relaxed morphology" (Rutishauser and Isler 2001): the organ circumscription of their body is hard to delineate and the phenotypic plasticity is high, depending on the growth substrate as well as on other environmental factors (Taylor 1989;Płachno and Adamec 2007). Despite being the richest and most widespread genus (at least 250 species occurring in five continents ;Taylor 1989;Fleischmann 2012) of carnivorous plants, Utricularia is instead less represented in Europe, where only nine species occur. ...
... Most of the diagnostic morphological features rely on flowers (Thor 1988;Taylor 1989;Tassara 2002), but these species are rarely flowering. For this reason, Astuti and Peruzzi (2018a) tried a traditional and geometric morphometric approach to test if even vegetative parts may provide diagnostic characters for species discrimination, as reported in various articles (Thor 1988;Taylor 1989;Moeslund et al. 1990;Tassara 2002;Schlosser 2003;Płachno and Adamec 2007;Gariboldi and Beretta 2008;Fleischmann and Schlauer 2014;Tison and de Foucault 2014). However, they demonstrated that shoot morphology, including features of quadrifid digestive glands, is not reliable and, in U. minor aggr., completely useless. ...
... The latter clade is in turn subdivided into two subclades: (1) one joining U. bremii, U. minor, and U. ochroleuca, with U. bremii and U. ochroleuca sister to each other and, together, sister to U. minor, and (2) the other one including U. intermedia and U. stygia. The closer relationship of U. ochroleuca with U. minor aggr., as compared with species of U. intermedia aggr., can be surprising based on morphological aspects, but a hybrid origin of U. ochroleuca and U. stygia, through a cross between U. minor and U. intermedia, was previously postulated, as well as several hybrids have been suggested to occur among European species (Neuman 1900;Lindberg 1921;Schlosser 2003;Płachno and Adamec 2007). Taylor (1989) assessed that putative hybrids are instead dysploid vegetative apomicts. ...
The main features to distinguish the seven native Utricularia species occurring in central Europe are found in flower shape, but being rarely flowering identification is often doubtful and uncertain. A recent morphometric work highlighted that there are no univocal reliable extra-floral morphological features allowing a safe identification at species level. Therefore, DNA barcoding approach is attempted here. Molecular analyses were performed to search for DNA barcodes using nuclear ITS (rDNA), plastid (cpDNA) trnL-trnF IGS and rps16 intron sequences. Generally, the barcoding approach failed to discriminate Utricularia species, although it could be of some help in the U. minor aggregate. With few exceptions, U. bremii shows peculiar DNA regions different from U. minor for both plastid markers investigated. However, interesting hypotheses could be derived from the obtained networks, including hybridization events to explain the rise of mostly sterile species, such as U. stygia. This species clusters with the other species of the U. intermedia aggregate in plastid phylogenetic graphs, while it is closely related to species of the U. minor aggregate in ITS phylogenetic graphs. Additionally to U. stygia, U. ochroleuca also shows some incongruences in the different markers, at least for some accessions, pointing to the possible occurrence of hybrids.
... The former glands secrete digestive enzymes serving prey digestion and, probably, also absorb released nutrients, while the latter glands pump the water out of the traps and form the negative pressure essential for prey capture (Sasago and Sibaoka, 1985;Adamec, 2018a;Poppinga et al., 2016Poppinga et al., , 2018Płachno et al., 2018). Regardless of the crucial role of the traps for prey capture and, thus, for plant ecophysiology, they can be used for reliable and quick determination of the three Utricularia species within the UI aggregate (Thor, 1988;Taylor, 1989;Kleinsteuber, 1996;Schlosser, 2003;Płachno and Adamec, 2007;Fleischmann and Schlauer, 2014). In UI, UO and US, quadrifid glands are X-shaped (see Fig. 6) and their exact shape (not the length of arms but the angles between them) is species specific. ...
... References: 1, Adamec, 2007a;2, Adamec, 2010a;3, Adamec and Lev (2002 accepted by botanists much later. Moreover, it was recognized later that UO is much rarer than US in Europe (e.g., Płachno and Adamec, 2007;Fleischmann and Schlauer, 2014). It is obvious that dimorphic shoots of UO ( Fig. 2) are morphologically and morphometrically (shoot length and branching rate) very similar to those of US (Thor, 1988;Kleinsteuber, 1996;Fleischmann and Schlauer, 2014;Astuti and Peruzzi, 2018b; Table 1). ...
... data). The quadrifid glands are markedly asymmetric (Fig. 6): the mean angle between the longer arms is 35°(range 19-52°) after Thor (1988) and 34°(range 26-45°) after Płachno and Adamec (2007), while that between the shorter arms is 171°(range 117-228°) after Thor (1988), but only 126°(range 107-161°) after Płachno and Adamec (2007) and 120-130°after Fleischmann and Schlauer (2014). The mean angle for North American populations of UO from Oregon and Colorado was only 104 ± 20°and 140 ± 26°, respectively (Schlosser, 2003). ...
Utricularia intermedia Hayne, U. ochroleuca R.W. Hartm., U. stygia Thor and U. bremii Heer ex Kölliker (Lentibulariaceae, Lamiales) are the four rarest and critically endangered European Utricularia (bladderwort) species from the generic section Utricularia. They are aquatic, submerged or amphibious carnivorous plants with suction traps which grow in very shallow, standing dystrophic (humic) waters such as pools in peat bogs and fens (also pools after peat or fen extraction), shores of peaty lakes and fishponds; U. bremii also grows in pools in old shallow sand-pits. These Utricularia species with boreal circumpolar distribution (except for U. bremii) are still commonly growing in northern parts of Europe (Scandinavia, Karelia) but their recent distribution in Central Europe is scarce to very rare following a marked population decline over the last 120 years. All species have very thin linear shoots with short narrow to filamentous leaves bearing carnivorous traps (bladders, utricles) 1-5 mm large. The first three species form distinctly dimorphic shoots differentiated into pale carnivorous ones bearing most or all traps, and green photosynthetic shoots with only a few (or without) traps, while the last species usually forms non-differentiated (monomorphic) or slightly differentiated shoots. The plants exhibit a marked physiological polarity along their linear shoots with rapid apical shoot growth. Their very high relative growth rate is in harmony with the record-high net photosynthetic rate of their photosynthetic shoots. Flowering of these species is common under favourable conditions and is stimulated by high temperatures but only U. intermedia sets seeds; the other species are sterile due to pollen malformation. Some molecular-taxonomic studies indicate that U. ochroleuca and U. stygia might be hybrids between U. intermedia and U. minor. All species propagate mainly vegetatively by regular branching and reach high relative growth rates under favourable conditions. All species form spherical dormant winter buds (turions). Suction traps actively form negative pressures of ca. -0.22 to -0.25 bar. The traps are physiologically very active organs with intensive metabolism: as a result of the presence of abundant glands inside the traps, which secrete digestive enzymes and absorb nutrients from captured prey carcasses (quadrifid glands) or take part in pumping water out of the traps and producing negative pressure (bifid glands), their aerobic respiration rate is ca. 2-3 times higher (per unit biomass) than that of leaves. Although oxygen concentrations inside reset traps are (almost) zero, traps are inhabited by many microscopic organisms (bacteria, euglens, algae, ciliates, rotifers, fungi). These commensal communities create a functional food web and in traps with captured macroscopic prey, they act as digestive mutualists and facilite prey digestion. Traps secrete a great amount of organic substances (sugars, organic acids, aminoacids) to support these commensals (‘gardening’). Yet the nutritional role of commensals in prey-free traps is still unclear. Quadrifid glands can also serve in the reliable determination of three species. Ecological requirements of U. intermedia, U. ochroleuca and U. stygia are very similar and include very shallow dystrophic waters (0-30 cm deep) with highly variable levels of dystrophy, common mild water level fluctuations, oligo-mesotrophic to slighly eutrophic waters, optimal pH values from 5.5-7.0 but always high free-CO2 concentrations of 0.8-1.5 mM. Limited data indicate that U. bremii is partly a stenotopic species preferring only slightly acidic to neutral (pH 6-7), very soft to slightly hard, oligo-mesotrophic waters. Yet it can grow well both in strongly dystrophic and clear waters, in peat bogs as well as sand-pits over peaty soil and clayish sand. Long-term, very low water levels in combination with habitat eutrophication, whatever the reason, leading to peat bog and fen infilling, are the most common and unfavourable ecological threads at the most sites of the four rare Utricularia species. However, ecological consequences of high-water level at the sites can be ambiguous for the populations: it reduces the strongly competitive cyperoid and graminoid species but can speed up site eutrophication. All four species are considered (critically) threatened in European countries and are usually under official species protection or their sites are protected. Regeneration of infilled fens or peat bogs and creation of shallow fen pools and canals in these mires, combined with (re)-introductions of these species have shown to be a very successful and efficient measure to protect the natural populations for many decades. Old shallow sand-pit pools have become outstanding substitution habitats for the protection of U. bremii.
... For this reason, some authors described shoot features that might help to discriminate taxa even without flowers (e.g. Thor 1988;Taylor 1989), but the reliability of these features was statistically tested only in a few cases (Płachno and Adamec 2007;Adamec 2016), and never with an all-species approach. ...
... For example, Thor (1988) split U. ochroleuca in two species, U. ochroleuca and U. stygia, claiming that, besides flowers, they have different angles between shorter arms (more obtuse in U. ochroleuca) and between shorter and longer arms (more obtuse in U. stygia) of quadrifid glands. Since its description, U. stygia has been recorded in many other sites throughout Europe (Schlosser 2003;Adamec 2007;Płachno and Adamec 2007;Fleischmann and Schlauer 2014), showing a distribution wider than U. ochroleuca. ...
... For example, Thor (1988) split U. ochroleuca in two species, U. ochroleuca and U. stygia, claiming that, besides flowers, they have different angles between shorter arms (more obtuse in U. ochroleuca) and between shorter and longer arms (more obtuse in U. stygia) of quadrifid glands. Since its description, U. stygia has been recorded in many other sites throughout Europe (Schlosser 2003;Adamec 2007;Płachno and Adamec 2007;Fleischmann and Schlauer 2014), showing a distribution wider than U. ochroleuca. ...
In central Europe, seven native species of Utricularia occur, mainly distinguished by flower features.
They can be subdivided in three aggregates according to shoot morphology: 1) U. intermedia aggr., also
comprising U. ochroleuca and U. stygia, 2) U. vulgaris aggr., also comprising U. australis and 3) U. minor
aggr., also comprising U. bremii . We tested some shoot features as identification tools and investigated
quadrifid digestive glands in all the studied species, using geometric morphometrics. For U. intermedia aggr., in
most cases the tooth number per ultimate leaf segment may be diagnostic. The three species of this aggregate
overlap in terms of gland shape, but averaging measurements by traps and individuals, a decrease of overlapping among species was found. The shape and the centroid size of quadrifid glands in U. minor aggr. is unsuitable for discriminating species. Concerning U. vulgaris aggr., U. vulgaris bears a higher ratio of setula length to tooth length than U. australis (which is more toothed). This feature may help to distinguish species, but conflicting results were found in one studied population. The relevance of quadrifid gland features as identification tool and the puzzling systematic circumscriptions of the target species are discussed.
... Utricularia ochroleuca (Fig. 85) The circumscription of Utricularia ochroleuca adopted here includes U. stygia, which was separated from the former by minor morphological differences (Thor 1988). Both taxa are sterile and apparently of hybrid origin (Thor 1988, Płachno & Adamec 2007. Morphological characters show some overlap and seem to be regionally correlated (Płachno & Adamec 2007). ...
... Both taxa are sterile and apparently of hybrid origin (Thor 1988, Płachno & Adamec 2007. Morphological characters show some overlap and seem to be regionally correlated (Płachno & Adamec 2007). These two forms may be different clones of a recurrently produced hybrid taxon rather than two distinct stabilized species. ...
The fifth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 106 taxa of the genera Arnica, Carduus, Cicuta, Coleanthus, Comarum, Dactylorhiza, Digitaria, Gagea, Gypsophila, Hieracium, Hydrocotyle, Leersia, Myosurus, Oenanthe, Oreopteris, Paris, Phalaris, Phegopteris, Pilosella, Polystichum, Portulaca, Pulicaria, Salicornia, Saxifraga, Suaeda, Thalictrum, Thelypteris, Tripolium, Utricularia, Veronica and Xeranthemum. These maps were produced by taxonomic experts based on herbarium specimens, literature and field records. Almost two-thirds of the mapped taxa are on the national Red List. These include endangered plants of rather dry habitats such as Gypsophila paniculata, Thalictrum foetidum, Veronica austriaca and Xeranthemum annuum as well as species of various sorts of wetlands such as Cicuta virosa and species of the genera Dactylorhiza and Utricularia, or fens and intermittently wet meadows including Oenanthe fistulosa, Thalictrum flavum and Th. simplex subsp. galioides. Particularly endangered are ecological specialists; for example, many species of saline habitats such as Salicornia perennans and Suaeda prostrata, both confined to saline habitats, are now extirpated from this country. In contrast, Saxifraga tridactylites, previously a rare species found mainly on base-rich rock outcrops, has become more abundant by spreading along railways during the last two decades. Maps based solely or mainly on herbarium records revised by experts are provided for taxonomically critical groups, particularly those of the genus Pilosella. Alien species mapped in this paper include both archaeophytes and neophytes, with various modes of introduction. For example, Carduus tenuiflorus has been introduced with wool, Digitaria ciliaris with cotton, Gypsophila perfoliata with iron ore from Ukraine, while the ornamentals G. elegans and G. scorzonerifolia escaped from cultivation. The halophytic Suaeda salsa is recorded as a new alien species for this country’s flora; it has recently colonized motorway verges of which the salinity of the soil was increased by the application of de-icing salts. Two archaeophyte species, Digitaria ischaemum and Portulaca oleracea, are now classified as invasive. Spatial distributions and often also temporal dynamics of individual taxa are shown in maps and documented by records included in the Pladias database and available in electronic appendices. The maps are accompanied by comments, which include additional information on the distribution, habitats, taxonomy and biology of the taxa.
... The shape of quadrifid glands in Utricularia traps is species-specific and they have therefore been used for easy determination of related species, mostly between U. ochroleuca s. str., U. stygia and U. intermedia (tHor 1988, tAyLor 1989, ScHLosser 2003, Płachno & AdAmec 2007. While the length and width of the long and short arms of the quadrifid glands were taken into account for species identification, the angles between the pairs of long and short arms were the main identification marks used. ...
... While the length and width of the long and short arms of the quadrifid glands were taken into account for species identification, the angles between the pairs of long and short arms were the main identification marks used. However, as reported in the literature (tHor 1988, tAyLor 1989, ScHLosser 2003, Płachno & AdAmec 2007, the morphometric parameters are rather variable; even within a single trap. Moreover, no study has yet raised the question of whether these parameters in mature traps depend on trap size. ...
... For one Utricularia species, morphometric measurements were conducted on 50 glands from 25 traps. The following parameters were measured using a ruler and a protractor: length and maximum width of both long and short arms and angles (to the nearest 0.3°) between the basal parts of long and also short arms (see tHor 1988, scHLosser 2003, Płachno & AdAmec 2007. The accuracy of trap length estimation was ca. ± 20 μm, while that of the length or width estimation of the arms was ca. ± 0.4 μm. ...
Quadrifid glands inside Utricularia traps consist of a basal cell and a tetrade of X-shaped terminal cells known as the long and short arms. They have digestive and absorptive functions associated with plant carnivory but their morphometry is commonly used for species determination. The interrelationship between the morphometric parameters of quadrifid glands in mature traps and trap length was estimated in three aquatic Utricularia species (U. vulgaris, U. australis, U. stygia). In these species, the ratio of trap length between the largest and smallest traps measured was 2.3-2.7. The total variability of width of both the long and short arms was relatively low in all species but the length of both the long and short arms was much greater; the ratio between the maximum and minimum lengths in each species was within 1.9-2.6. Linear regression models revealed significant correlations between long arm lengths and trap lengths in all species. This also applied for short arms except in U. australis. In U. vulgaris and U. australis, both the long and short arm widths correlated highly significantly with trap length, while the correlation was significant only in U. stygia short arms. In all species, the angles between the long arms did not correlate with trap length. With the short arms, the angles correlated highly significantly with trap length only in U. stygia, but not at all in the other species. For species determination purposes, only mature traps of uniform, mean size should be used to reduce the otherwise great variability of gland morphometry.
... This is the first report on osmophore ultrastructure not only for the stem-succulent stapeliads (Asclepiadoideae-Ceropegieae-Stapeliinae ) but to our knowledge for the Asclepiadoideae at all. Floral rewards and the presence and structure of osmophores, nectaries, elaiophores and trichomes are useful features in plant taxonomy, as has been shown in, for example, orchids (Curry et al., 1991; Davies and Stpiczy nska, 2006, 2007; Davies and Turner, 2004; Pansarin and Amaral, 2008; Stpiczy nska et al., 2007), Droseraceae (Conran et al., 2007) and European bladderworts (P"achno and Adamec, 2007; Thor, 1988). The aim of this work was to determine which structures and mechanisms on the ultrastructural level are involved in the release of the carrion odor of Orbea variegata flowers, and to compare these findings with stinking flowers of Boucerosia indica (the only leafy stapeliad). ...
Carrion flower stapeliads are examples of olfactory mimicry, forming sapromyiophilous flowers, which mimic food sources or oviposition sites to attract fly pollinators. The aim of this work was to investigate the ultrastructure of osmophores involved in the release of the carrion odor of Orbea variegata and Boucerosia indica flowers. In spite of their similar architecture (epidermal epithelium+subepidermal secretory layers), the osmophores of stapeliads feature some differences in morphology and ultrastructure. The epidermal epithelial cells of O. variegata and B. indica differ in shape, but both are extremely rich in endoplasmic reticulum and flocculent material in the vacuole. Unlike the Orbea, Boucerosia has starchless leucoplasts in the epidermal epithelium. Orbea features a cuticle with microchannels, while Boucerosia has a different mechanism for the pathway of scent substances to the cell exterior. They are released by rupturing of the outer layer of cuticle at the apex of the papillae. The epidermal cells of the adaxial corolla differ even between parts of the corolla, the corolla lobes and the annulus in the flower. This diversity may be connected with an odor gradient. The morphological and anatomical features of stapeliad (subtribe Stapeliinae) osmophores are generally similar to osmophores of members of subtribe Ceropegiinae (Ceropegia), thus, we suggest that this model of osmophores evolved before early diversification of Ceropegieae. The ultrastructural features of stapeliad osmophores are generally similar to those of Araceae, Orchidaceae and Passifloraceae.
... Utricularia stygia, U. ochroleuca and U. intermedia grow in very similar habitats in shallow, standing, dystrophic (humic), acidic waters, in fen lakes, bogs and peaty fishponds. However, they very rarely grow together in the same wetland (Adamec & Lev 2002, Płachno & Adamec 2007. Generally, the species show a rather wide ecological tolerance of many water chemistry factors (Melzer 1976, Pietsch 1977, Dierssen & Dierssen 1984, Schäfer-Guignier 1994, Harms 1999, Hofmann 2001 and their ecological limits are similar (Kosiba & Sarosiek 1989, Kosiba 1993, 2004, Adamec & Lev 2002. ...
... As shown over the last decade this taxon, though reluctantly accepted by botanists, is more common in Europe than U. ochroleuca s. str. (Hofmann 2001, Schlosser 2003, Płachno & Adamec 2007. In this paper, the name U. ochroleuca will be used only for U. ochroleuca s. str. ...
... In the Czech Republic, U. ochroleuca and U. intermedia are considered to be critically endangered but U. stygia is not officially mentioned (Holub & Procházka 2000). The Třeboň basin in S Bohemia is the centre of their recent distribution in the Czech Republic (Płachno & Adamec 2007). Here, 11 sites for U. ochroleuca or U. stygia and six for U. intermedia were verified within the period 2003-2005 (L. ...
Utricularia stygia Thor and U. intermedia Hayne are aquatic carnivorous plants with distinctly dimorphic shoots. Investment in carnivory and the morphometric characteristics of both types of shoots of these plants were determined in dense stands growing in shallow dystrophic waters in the Třeboiň basin, Czech Republic, and their possible ecological regulation and interspecific differences considered. Vertical profiles of chemical and physical microhabitat factors were measured in these stands in order to differentiate key microhabitat factors associated with photosynthetic and carnivorous shoots. Total dry biomass of both species in dense stands ranged between 2.4-97.0 g·m-2. The percentage of carnivorous shoots in the total biomass, which was used as a measure of the investment in carnivory, ranged from 40-59% and that of traps from 18-29% in both species. The high percentage of total biomass made up of carnivorous shoots in both species indicates both a high structural investment in carnivory and high maintenance costs. As the mean length of the main carnivorous shoots and trap number per plant in carnivorous shoots in both species differed highly significantly between sites, it is probable that the investment in carnivory is determined by ecological factors with low water level one of the potentially most important. Marked differences were found only in [O2] between the 1-3 cm deep free-water zone with green photosynthetic shoots of both species and the 10 cm deep loose sediment with chlorophyll-free carnivorous shoots with traps (range 1.7-7.2 vs. 0.0-0.8 mg·l-1). The waters can be characterized as mesotrophic. Though anoxia occured consistently at a depth of 10 cm in loose sediment at all U. stygia and U. intermedia sites the carnivorous shoots of both species growing in this microhabitat are able to survive and do not avoid this microhabitat.
