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Pollen morphology of Beta trigyna, B. vulgaris and B. vulgaris subsp. maritima, last of those studied for the first time, was investigated using light and scanning electron microscopy, based on 10 herbarium specimens. The aim of the study was to provide detailed data on the pollen characteristics of these taxa to identify similarities and differences between them. Pollen grains are pantoporate, spheroidal, circular in outline; small- and medium-sized. Exine sculpture is nanoechinate, tectum is psilate or psilate-perforate. Pore membranes are nanoechinate. Diagnostic relevance of the characters of pollen grains is discussed (pollen and pore diameters, distance between pores and between pore centres, nanoechini size and density, number of nanoechini on pore membranes, structure of columellae). UPGMA dendrograms based on palynological data support the differentiation of B. trigyna (section Corollinae), B. vulgaris and B. vulgaris subsp. maritima (section Beta). The obtained characteristics of pollen grains of Beta species can be used in spore-pollen analysis, especially in identifying the impact of human economic activity in the past. [ABSTRACT FROM AUTHOR]

Based on molecular phylogenetic and morphological studies, the new genera Sedobassia Freitag & G. Kadereit and Spirobassia Freitag & G. Kadereit were described in the tribe Camphorosmeae (Chenopodiaceae/Amaranthaceae sensu APG IV). Palynomorphological peculiarities are often used in taxonomy as additional diagnostic features. Pollen grains from 26 herbarium specimens belonging to 13 taxa of Bassia, Sedobassia, Spirobassia and Neokochia genera in Eurasia and North America were acetolyzed and studied using both light microscopy and scanning electron microscopy. Dry pollen grains were also studied. The structure of the columellae of pollen grains was analyzed for the first time in the current study. The aim of this research was to provide data on their pollen characteristics and to evaluate the taxonomic value of these data for generic and species-specific identification. The pollen grains are pantoporate, spheroidal in shape, circular in outline, slightly undulate, undulate or straight on the edges; and medium- or small-sized. Pores are circular, with distinct or indistinct margins. Exine sculpture is nanoechinate; tectum psilate or psilate-perforate. Pore membranes with nanoechini. Taxonomic relevance of the most important characters of pollen grains is discussed (pollen diameter, pore number, pore diameter, distance between pores and between pore centers, pollen diameter(C)/distance between pore centers(D) value, nanoechini density, presenсe/absence of perforations, structure of columellae, number of nanoechini on pore membranes). Pollen morphology proved to be an important additional source of information for species-specific identification. This study provides new data and analyzes the morphological features of pollen grains of Bassia (in the currently accepted circumscription), palynomorphological similarities, and differences between taxa of the genera Bassia, Sedobassia, Spirobassia, and Neokochia. [ABSTRACT FROM AUTHOR]

Recent molecular phylogenetic studies of Camphorosmoideae (Chenopodiaceae) demonstrated that Camphorosma is monophyletic. Palynomorphological peculiarities are used in taxonomy as additional diagnostic features and pollen analysis. Pollen morphology was studied using light and scanning electron microscopy, based on 13 specimens belonging to four species (C. annua, C. lessingii, C. monspeliaca and C. songorica). The aim of this research was to provide new data on pollen characteristics of the above mentioned species and to evaluate their taxonomic value. The results obtained show that pollen grains are pantoporate, spheroidal, circular in outline, undulate or slightly undulate on the edges; small or medium-sized. Pores are circular, with distinct margins. Exine sculpture is nanoechinate, tectum psilate or psilate-perforate. Pore membranes are nanoechinate. Taxonomic relevance of the most important characters of pollen grains (pollen diameter, pore number, pore diameter, distance between pores and between pore centres, C/D value, nanoechini density, presence/absence of perforations, number of nanoechini on pore membranes, structure of columellae) is discussed. The exine structure of pollen grains of all species was analysed for the first time in the current study. Pollen morphology proved to be an important additional source of information for taxonomy for species-specific identification and pollen analysis within Camphorosma. Palynomorphological data are interpreted in the existing phylogenetic framework. [ABSTRACT FROM AUTHOR]

Pollen morphology of six species from the Macranthera-Agalinis clade (Orobanchaceae) was studied using both light microscopy and scanning electron microscopy. Pollen grains are (2-)3(4-)-colpate, 3-brevicolpate and 4-, rarely 6-porate, obtate to prolate (P/E = 0.72–1.52) in shape; medium-sized and rarely large-sized (P = 26.60–50.54 µm, E = 22.61–47.88 µm). Three pollen types are found and described based on the pollen grain size, length of the colpi, exine thickness, exine sculpture, columellae length and thickness and nanogemmae size. Type III contains three subtypes differentiated by pollen grain size, length of the colpi, exine thickness, exine sculpture, columellae length and nanogemmae size. Unweighted pair group method with arithmetic mean (UPGMA) dendrograms based on palynological data support that Dasistoma macrophylla has unique morphological and morphometric characters. In D. macrophylla we observed a transition from the 3-brevicolpate type to the 4-porate and occasionally 6-porate type. This polymorphism with respect to apertures may provide an advantage for D. macrophylla to survive under different ecological conditions and on a wide range of hosts. Palynomorphological data are interpreted in the existing phylogenetic framework. The 3-colpate type of apertures and a nanogemmate exine sculpture are hypothesised to be the plesiomorphic condition within the Macranthera-Agalinis clade. [ABSTRACT FROM AUTHOR]

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Pollen morphology of herbarium specimens of four Centranthus species (C. ruber, C. longiflorus, C. kellereri and C. calcitrapae) was studied using LM and SEM. The research aim was to provide data on their pollen characteristics and to evaluate the taxonomic value of these data for species-specific identification. Pollen grains are tricolpate, suboblate to prolate (P/E = 0.81–1.42); medium- or large-sized (P = 49.21–90.44 µm; E = 43.89–93.10 µm). Colpi are long or medium-length, wide at equator, tapered to acute or obtuse ends. Exine sculpture is echinatemicroechinate-nanoechinate; echini (1.00–1.39 µm high) and microechini (0.55–0.98 µm) are conical, with straight or convex sides and acute apices, nanoechini are 0.22–0.46 µm high. Most important characters of taxa diagnostic at species level for the taxonomy are: size of pollen and colpi, exine structure, size of echini and microechini, and pattern of tectum in areas between echini. Pollen grains of C. calcitrapae and C. macrosiphon (sect. Calcitrapa) are generally smaller in size than grains of C. ruber, C. longiflorus and C. kellereri (sect. Centranthus). Pollen of C. kellereri was analysed for the first time in the current study. [ABSTRACT FROM AUTHOR]

Palynology gives the evidence for identification and elimination of taxonomically complex genera. Pollen morphology of nine species (three subg., three sect.) of the genus Cephalaria Schrad. was studied using light microscopy and scanning electron microscopy. Pollen grains of all investigated species are triporate, suboblate to subprolate (P/E = 0.75–1.28), and large‐sized (P = 58.52 μm–114.38, E = 63.84–119.70 μm). The outline of pollen grains in equatorial view is circular or elliptic, in polar view circular, circular‐triangular, or triangular. Pores are distinct, lolongate, elliptic, or circular, with an annulus, operculum, and distinct or indistinct, wide halo surrounding the aperture. Exine sculpture is echinate‐microechinate or echinate‐microechinate‐nanoechinate. Additional diagnostic characters at the species level in Cephalaria Schrad. that can be used for the purposes of taxonomy are size of pollen grains and pores, the shape of pores, the width of the annulus, structure of the exine, dimension of echini and microechini, location of microechini, and presence/absence of nanoechini. Palynomorphological data are compared with the taxonomical classification system of investigated taxa. It is shown that pollen grains morphology of the genus Cephalaria Schrad. is similar to the pollen morphology of the genus Dipsacus L., which confirms their inclusion in the Dipsaceae tribe. [ABSTRACT FROM AUTHOR]

Pollen morphology of representatives of the genera Succisa and Succisella in the flora of Ukraine was studied using light and scanning electron microscopy. Pollen grains in both taxa were tricolpate, prolate, rarely oblate-spheroidal or spheroidal; large-sized. Their outline in polar view was subcircular, rarely trilobate, in equatorial view elliptical or rarely circular. Colpi short, of variable width, margins irregular with distinct, narrow margo, and blunt or acute ends. Exine sculpture was echinate-microechinate. The revealed characteristics of pollen grains are taxonomically significant at the generic and specific levels, and they can be used in pollen analysis. Palynomorphological data are consistent with the results of recent molecular phylogenetic studies. Data on pollen morphology also confirm taxonomic circumscription of Succiseae V. Mayer & Ehrend. Pollen grains in Succiseae are characterized by a tricolpate aperture type, which was probably ancestral in Dipsacaceae s. str. [ABSTRACT FROM AUTHOR]