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The current study aims to understand the role of various morphological features of pollen grains in attachment with moth proboscides. To test the hypothesis, moth samples are collected from 11 sites in three districts of Arunachal Pradesh and West Bengal, North East India. Pollen of 18 angiosperm families are isolated from the proboscides of 16 moth species in four families. We selected proboscides for the isolation of pollen because it is the most important organ of moths which interacts with flowers during moth visitation. The isolated pollen is studied for various morphological characters like pollen shape, unit, exine ornamentation, thickness, aperture numbers, and aperture types along with specialized structures i.e., viscin thread and pollenkitt, and analyzed for their attachment on the proboscides. The present study revealed the significant role of pollen shape, unit, exine characters, viscin thread, and pollenkitt in attachment with proboscides. Whereas, the aperture numbers and aperture types are found insignificant in the process of pollen attachment. Studies on the formation of viscin thread and pollenkitt may be established as an important tool to understand the specialized and generalized interactions between moths and angiosperms. The present study will open up a new horizon in pollination ecology. [ABSTRACT FROM AUTHOR]

The main objective of this research was to conduct a comparative pollen morphological analysis of some representatives of the genus Cuscuta in relation to taxonomy. Investigations of 38 species and 1 variation revealed that not only the number, but the colpi length, as well as the exine ornamentation (at the SEM level), can be regarded as a diagnostic feature. For all the taxa studied, the common zonocolpate type of pollen was observed, represented by three variations: I) colpi long; II) colpi of medium length; III) colpi short. In combination with colpi length, variations in the number of colpi were also identified, such as: I) 3(4)-zonocolpate pollen grains with long colpi (in most of the species studied from subgenera Grammica and Cuscuta , as well as in C. monogyna from the subgenus Monogynella ); II) 4(3)-zonocolpate pollen grains, with long colpi ( C. cristata from subgenus Grammica ); III) 3-zonocolpate pollen grains both with long colpi and colpi of medium length ( C. abyssinic a from subgenus Cuscuta and C. africana , C. angulata from subgenus Pachystigma ); IV) 3-zonocolpate pollen grains with colpi of medium length were noted for species from all four subgenera ( C. cassytoides , C. lupuliformis from subgenus Monogynella , C. kotschyana from subgenus Cuscuta , C. nitida from subgenus Pachystigma and C. jalapensis , C. rostrata , C. suaveolens from subgenus Grammica ); V) 3–4- or 4-zonocolpate, with short colpi ( C. lehmanniana and C. gigantea from subgenus Monogynella respectively); VI) 5–6-zonocolpate, with short colpi ( C. reflexa from subgenus Monogynella ). Using SEM, three main types of exine ornamentation were also identified: perforate, foveolate and reticulate. The last type in the vast majority of the cases was presented in combination with echinae (rarely with spines or granules). The data revealed that the presence of the significant similarity of palyno-morphological characteristics in representatives of the subgenera Cuscuta , Pachystigma and Grammica , with the exception of the species Lepidanche adpressa (syn. C. compacta ), makes it difficult to create an identification key at the level of individual subgenera. Pollen features can be most clearly used only to distinguish the subgenus Monoginella , reflecting its certain isolation within the entire Cuscuta genus. The presence of a highly specialized reticulate exine ornamentation in Lepidanche adpressa (syn. C. compacta ), not identified for the pollen of any of the studied taxa of the subgenus Grammica , indicates a significant proximity of this species to the subgenus Monogynella . For the species C. reflexa , the obtained palyno-morphological data are consistent with the previous opinion about the separation of this species, as well as its more advanced position within the genus Cuscuta .

Pollen analysis is essential for discerning the botanical and geographical origins of honey, ensuring authenticity, quality, and commercial value. The Sahara Desert in Algeria boasts unique floral diversity, with its melliferous plant species contributing to regional honey production. Nevertheless, a lack of comprehensive information on the pollen characteristics of these plants impedes precise identification of the geographical and botanical origins of Saharan honeys. Given the importance of understanding honey origin for quality assurance, this study addresses the challenge posed by the scarcity of melissopalynological data in the Sahara Desert. By offering a detailed characterization of Sahara Desert melliferous plant pollen, the research contributes valuable insights to the broader field of honey authentication and underscores its significance in the industry. Therefore, this study was conducted to characterize the pollen of melliferous plants in the Sahara Desert, which is essential for establishing a database that can aid in the determination of honey origins, protect against fraudulent activities, and support conservation efforts. This study aimed at the characterization of pollen of spontaneous melliferous plants from the Sahara Desert of Algeria to facilitate the determination of the geographical and botanical origin of honeys produced in this region. In three regions (Ghardaïa, Touggourt and Ouargla), pollen morphological features namely: polar length (PL) and equatorial diameter (ED), size, shape, apertures and exine ornamentations of 19 native plant species were studied through the sampling of ten flowers per plant and ten pollen grains per flower for each species (n = 3800 measurements). The surveyed plant species showed that medium-sized pollens (25–50 µm) were the most dominant (73.34 %), followed by slam-sized pollens (21.18 %), with the smallest size observed in Tetraena alba (PL = 18.98 ± 4.82 μm, ED = 18.95 ± 5.06 μm) and the largest size measured in Faidherbia albida (PL = 58.03 ± 4.65 µm, ED = 57.46 ± 4.70 μm). The most frequent forms of pollen in different species were prolate-spheroidal (32.68 %) and oblate-spheroidal (26.53 %). Diverse types of exine ornamentations and were detected at the pollen unit level with a dominance of reticulate (57.89 %). Tricolporate (42.11 %) and tricolpate (31.58 %) were the dominate pollen apertures. This study characterized pollen from Sahara Desert melliferous plants, which can aid honey origin determination, ensuring quality and supporting conservation, with implications in authentication, protection, and preservation of floral resources for sustained honey production.

The main objective of this research was to conduct a comparative pollen morphological analysis of some representatives of the genus Cuscuta in relation to taxonomy. Investigations of 38 species and 1 variation revealed that not only the number, but the colpi length, as well as the exine ornamentation (at the SEM level), can be regarded as a diagnostic feature. For all the taxa studied, the common zonocolpate type of pollen was observed, represented by three variations: I) colpi long; II) colpi of medium length; III) colpi short. In combination with colpi length, variations in the number of colpi were also identified, such as: I) 3(4)-zonocolpate pollen grains with long colpi (in most of the species studied from subgenera Grammica and Cuscuta, as well as in C. monogyna from the subgenus Monogynella); II) 4(3)-zonocolpate pollen grains, with long colpi (C. cristata from subgenus Grammica); III) 3-zonocolpate pollen grains both with long colpi and colpi of medium length (C. abyssinica from subgenus Cuscuta and C. africana, C. angulata from subgenus Pachystigma); IV) 3-zonocolpate pollen grains with colpi of medium length were noted for species from all four subgenera (C. cassytoides, C. lupuliformis from subgenus Monogynella, C. kotschyana from subgenus Cuscuta, C. nitida from subgenus Pachystigma and C. jalapensis, C. rostrata, C. suaveolens from subgenus Grammica); V) 3–4- or 4-zonocolpate, with short colpi (C. lehmanniana and C. gigantea from subgenus Monogynella respectively); VI) 5–6-zonocolpate, with short colpi (C. reflexa from subgenus Monogynella). Using SEM, three main types of exine ornamentation were also identified: perforate, foveolate and reticulate. The last type in the vast majority of the cases was presented in combination with echinae (rarely with spines or granules). The data revealed that the presence of the significant similarity of palyno-morphological characteristics in representatives of the subgenera Cuscuta, Pachystigma and Grammica, with the exception of the species Lepidanche adpressa (syn. C. compacta), makes it difficult to create an identification key at the level of individual subgenera. Pollen features can be most clearly used only to distinguish the subgenus Monoginella, reflecting its certain isolation within the entire Cuscuta genus. The presence of a highly specialized reticulate exine ornamentation in Lepidanche adpressa (syn. C. compacta), not identified for the pollen of any of the studied taxa of the subgenus Grammica, indicates a significant proximity of this species to the subgenus Monogynella. For the species C. reflexa, the obtained palyno-morphological data are consistent with the previous opinion about the separation of this species, as well as its more advanced position within the genus Cuscuta. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the pollen morphology of eight taxa of Tephrosia, namely T. falciformis. T. purpurea subsp. leptostachya, T. purpurea subsp. purpurea, T. subtriflora, T. strigosa, T. uniflora subsp. petrosa, T. villosa and T. wallichii occurring in Indian Thar desert. Safranin-stained and acetolysed pollen grains were used to describe their morphology. The pollen characters investigated include pollen size, shape, polarity, symmetry, aperture type and exine ornamentation. The pollen grains are monads, small (10-25 µm) to medium (25-50 µm), isopolar and radially symmetrical; they are smallest in T. strigosa and biggest in T. purpurea subsp. leptostachya. The exine ornamentation varies from reticulate, micro-reticulate, rugulate-reticulate and foveolate to foveolate-reticulate. A taxonomic key is provided based-on pollen to discriminate Tephrosia taxa investigated. [ABSTRACT FROM AUTHOR]

Iridaceae L. is a large and well-known plant family that is widely distributed across the northern hemisphere. According to recent and ongoing taxonomic revision, its largest genus, Iris L., includes 14 species of perennial herbs occurring in Korea. Although pollen morphological data have proved crucial to the resolution of systematic relationships within the Iris genus, detailed palynological studies of Korean irises are scarce. Thus, this study aimed to describe the pollen morphology of 14 species representing two subgenera (Limniris and Pardanthopsis) of Korean Iris and one closely related species (Sisyrinchium rosulatum) using scanning electron microscopy. Pollen grains of all studied taxa were large in size (P = 35.9–86.7 μm, E = 37.3–72.9 μm), oblate (P/E = 0.68) to prolate (P/E = 1.99) in shape, and monosulcate with a granulate-perforate aperture membrane. Three types of exine ornamentation were identified in Korean Iris species: perforate (Type I); microreticulate (Type II); and reticulate (Type III), which was divided into four distinct subtypes based on lumen diameter. The observed pollen micromorphological characters enabled species distinction and taxonomic delimitation to the series level in the genus. The pollen morphological data presented in this study may be of systematic significance to Korean Iris species. [ABSTRACT FROM AUTHOR]

Pollen studies can assist in distinguishing different plant taxa on the basis of pollen diameter, exine thickness, spines length, spine shape, number of rows of spines between colpi, shape of pollen, P/E ratio, pollen class and aperture type. Light microscopy (LM) and scanning electron microscopy (SEM) was used to compare and differentiate two Malva species on the basis of different pollen characteristics. Pollen in Malva neglecta and Malva parviflora had punctate and subpsilate, and, granulate and verrucate sculpturing between spines respectively. Both species pollen had bulbous spine base, but were more swollen in M. parviflora. M. neglecta had more pollen size, spine length and distance between spine base and spine apex, except spine base and pore diameter. The scatterplot matrix showed a wide variation among sculpturing types and other pollen attributes of both species. In PCA biplot, pore diameter and spine length were linked to M. parviflora while other pollen attributes were clearly linked to M. neglecta, indicating the taxonomic significance of the observed characters. It was concluded that the palynological studies can act as an identification tool and are of great significance in delimiting Malva and different plant taxa. Research Highlights: Taxonomic identifications is a big problem in morphologically identical Malva neglecta and Malva parviflora.The usefulness of pollen morphology (pollen diameter and exine thickness) and wall ornamentation in identification through light microscopy (LM) and scanning electron microscopy (SEM) was confirmed.Pollen of M. neglecta can be differentiated from M. parviflora by its sculpturing patterns.Spine base and pore diameter of M. parviflora is a taxonomically important feature. [ABSTRACT FROM AUTHOR]

The present study investigated the palynological diversity of highly medicinal Rare, Endangered, and Threatened (RET) plant species dwelling in higher altitudes of Western Himalaya, India. The pollen morphology of 32 plant species covering 29 genera, 23 families, and 18 orders of Angiosperms was analyzed by Light Microscopy (LM) and Scanning Electron Microscopy (SEM). The families of the studied plant species have been arranged and discussed following the evolutionary sequence as per the updated version of Angiosperm Phylogeny Group IV. The studied pollen characters were found to be helpful in the delimitation of taxa at the species level. In the studied monocots, the species belonging to order Zingiberales, Asparagales, and Liliales followed the general trend of having primitive inaperturate to advance monosulcate pollen except for Alismatales which had inaperturate pollen and placed after the orders mentioned above in the APG IV classification system. The pollen aperture of the eudicot group in the present study followed the evolutionary pattern from tricolpate to tricolporate and triporate, which corroborated previous reports. All the investigated species of both monocot and eudicot groups had monad pollen units suggesting their primitiveness on the evolutionary scale except for the Rhododendron companulatum (Ericales), having evolutionarily advanced tetrad arrangement. The current study found primitive exine ornamentation in Ranunculales to advance in Asterales, Lamiales, Gentianales, and Boraginales and confirms the results of the previous studies. The data on the pollen morphological features of the studied species generated in the present study will help understand these important high-altitude plant species' reproductive biology and conservation aspects. [ABSTRACT FROM AUTHOR]

The present study investigated the palynological diversity of highly medicinal Rare, Endangered, and Threatened (RET) plant species dwelling in higher altitudes of Western Himalaya, India. The pollen morphology of 32 plant species covering 29 genera, 23 families, and 18 orders of Angiosperms was analyzed by Light Microscopy (LM) and Scanning Electron Microscopy (SEM). The families of the studied plant species have been arranged and discussed following the evolutionary sequence as per the updated version of Angiosperm Phylogeny Group ІV. The studied pollen characters were found to be helpful in the delimitation of taxa at the species level. In the studied monocots, the species belonging to order Zingiberales, Asparagales, and Liliales followed the general trend of having primitive inaperturate to advance monosulcate pollen except for Alismatales which had inaperturate pollen and placed after the orders mentioned above in the APG ІV classification system. The pollen aperture of the eudicot group in the present study followed the evolutionary pattern from tricolpate to tricolporate and triporate, which corroborated previous reports. All the investigated species of both monocot and eudicot groups had monad pollen units suggesting their primitiveness on the evolutionary scale except for the Rhododendron companulatum (Ericales), having evolutionarily advanced tetrad arrangement. The current study found primitive exine ornamentation in Ranunculales to advance in Asterales, Lamiales, Gentianales, and Boraginales and confirms the results of the previous studies. The data on the pollen morphological features of the studied species generated in the present study will help understand these important high-altitude plant species' reproductive biology and conservation aspects.

Xenostegia D.F.Austin et Staples is a small genus in the family Convolvulaceae, with five species restricted to Africa, and one species widespread across the Paleotropics. It was initially established to accommodate two species in Merremia that possessed non-spinulose pantoporate pollen, rare in the family, along with stigma and anther characters that did not fit other genera entirely. Recent molecular studies, and the discovery of a new species in Central Africa, have expanded the delimitation of this genus from two to six species. Our survey captures the palynological variation of all currently documented species of Xenostegia, revealing that more types of pollen aperture patterns are present (15- and 30-colpate), with implications for the circumscription of the genus. In addition, a unique pattern of exine sculpture (plurigemmate-echinate) was discovered, which is shared by all the species and has not yet been documented in any other member of family Convolvulaceae. [ABSTRACT FROM AUTHOR]

In this research, pollen micromorphology and ultrastructure of eight species belonging to genera including Alrawia, Bellevalia, Fessia, Muscari, Othocallis, Prospero, Puschkinia, and Zagrosia were investigated by light microscopy, scanning electron microscopy, and transmission electron microscopy. The pollen size varied among the studied species. Othocallis monanthos and Muscari neglectum had the largest and smallest pollen grains, respectively. Based on the Polar axis/Equatorial axis (P/E) ratio, Bellevalia saviczii had peroblate pollen shape and the rest were oblate. Exine ornamentation on the equatorial surface, sulcus margin exine ornamentation, and intine ornamentation in the sulcus membrane region of the pollen grains varied among the selected species of all genera. The exine layer in all genera had semitectate tectum, simplicolumellate infratectum, and discontinuous foot layer. There was discontinuous endexine in M. neglectum, Prospero autumnale, and Zagrosia persica. Alrawia bellii, P. autumnale, and Puschkinia scilloides had three intine layers in the sulcus membrane region, O. monanthos had two, and the rest of the species had one. Also, in those species with three layers in the sulcus membrane region, the outer intine layer had many channels. A dendrogram of the palynological characters grouped them into three pollen types and six pollen subtypes. The pollen types verified the phylogenetic relationships among the studied genera, whereas the pollen subtypes partly supported these relationships. [ABSTRACT FROM AUTHOR]

Species of sect. Chrysantha have high ornamental value, but their classifications are controversial. In order to study the morphological characteristics and taxonomic significance of pollen in sect. Chrysantha, we observed morphological shape, exine ornamentations and perforation characteristics of 10 species of sect. Chrysantha pollen grains by scanning electron microscope, and the polar axis, equatorial axis and length of germination groove were analyzed by clustered. The results were as follows:(1)The pollen of sect. Chrysantha was medium-sized and most of them were subspherical, only C. indochinensis var. tunghinensis was oblate sphere and C. impressinervis was prolate; The extine ornamentation of pollen could be broadly divided into three types: tuberculate-baculate, ornate and verrucate, and the size and density of surface perforation were obviously different.(2)Cluster analysis showed that the pollen morphology of C. perpetua, C. petelotii var. grandiflora, C. petelotii and C. euphlebia were proximity; C. flavida, C. indochinensis, C. micrantha and C. indochinensis var. tunghinensis had similar characteristics; However, C. pubipetala and C. impressinervis were clearly different from the others. The extine ornamentation and perforation of pollen were different, but it was still necessary to combine the polar axis, equatorial axis and the length of germination groove to clearly distinguish the 10 species of sect. Chrysantha. From the perspective of palynology, the pollen of sect. Chrysantha has the general characteristics of Camellia without specificity, and this group plants may not be an independent group, but the pollen morphology of this group plants has obvious inter-specific differences, which can be used as the basis for taxonomy. The results of this study provide the basis for the taxonomic status among species of sect. Chrysantha. [ABSTRACT FROM AUTHOR]

The palynomorphology of 19 modern species of the genus Quercus L. native to Armenia and adjacent regions, including the Caucasus and Transcaucasia, the Mediterranean region (especially Turkey), as well as Iran, Iraq and Afghanistan, was studied using light microscopy (LM) and scanning electron microscopy (SEM). The work revealed two main types of apertures (3-zonocolpate, 3-zonocolp-porate) as well as six morphological types of pollen based on three main types of exine ornamentation (tuberculate, verrucate, rugulate). We suggest that two main groups of exine ornamentation developed from a common initial type. The first group covers all species of the subgenus Quercus and also Q. suber and Q. alnifolia of the subgenus Heterobalanus. The second group is limited to the morphological type Q. ilex (species Q. ilex, Q. coccifera, subgenus Heterobalanus). On the other hand, the presence of widespread interspecific and introgressive hybridization within the genus Quercus indicates an ongoing process of speciation. This also has an effect on pollen features, which are very similar in a number of species but also vary in individual samples even within the same species. The morphological uniformity of the pollen surface (especially for the subgenus Quercus), the presence of islets of secondary sporopollenin on the surface of pollen grains, as well as orbicules in anthers, do not indicate general primitiveness of representatives of this genus but most likely denote a relatively high degree of speciation activity within this group.

The present study aimed to understand the pollen morphological variation among and within the Rosa L. species of Western Himalaya, India, and to investigate whether the pollen characters may help to distinguish these species of roses. The pollen morphology of nine Rosa species viz. R. canina L., R. centifolia L., R. damascena Mill., R. foetida var. persiana (Lem.) Rehder, R. moschata Herrm, R. multiflora Thunb, R. nanothamnus Boulenger, R. webbiana Wall. ex Royle, and R. macrophylla Lindl were studied. A total of 31 accessions of roses were collected from Jammu and Kashmir, Ladakh, and Himachal Pradesh. Ten quantitative characters, i.e., length of the polar axis (P), length of equatorial axis (E), exine thickness (Ex), length of colpi (LeC), width of striae (Sr), width of groove (Gr), number of striae (Ns), Polar area index (PAI) and P/E ratio were studied. The measurements and observations were carried out with both light microscopy and scanning electron microscopy. Pollen grains of all the studied species were tricolporate. Prolate and subprolate shapes were the dominant pollen shape types. The highest and lowest polar axis length was observed for R. canina (32.73 µm) and R. moschata (25.42 µm), respectively. The average colpi length in the studied species was 22.19 µm, with R. macrophylla having a minimum length of 13.42 µm and R. canina with a maximum length of 34.03 µm. Results of the principal component analysis indicated that the principal component (PC1) attributed 42.10% of the total variation, and positively associated with P, E, LeC, and Ns. Exine ornamentation almost distinguished all the species of Rosa in this study. [ABSTRACT FROM AUTHOR]

ABSTRACT: In this presented work, the pollen morphologies of twenty-one taxa, nine of them endemic from Turkey, belonging to the genus Salvia (Lamiaceae: sub-family Nepetoideae: tribe Mentheae: sub-tribe Salviinae), S. aethiopis L., S. argentea L., S. aytachii Vural & Adigüzel, S. blepharochlaena Hedge & Hub.-Mor., S. cadmica Boiss., S. ceratophylla L., S. cryptantha Montbret & Aucher, S. frigida Boiss., S. fructicosa Miller, S. halophile Hedge, S. napifolia Jacq., S. microstegia Boiss. & Bal., S. recognita Fisch. & Mey. S. sclarea L., S. smyrnaea Boiss. S. suffruticosa Montbret & Aucher, S. tchihatcheffii (Fisch. & Mey.) Boiss., S. tometosa Bertol, S. verbenaca L., S. viridis L., and S. wiedemanni Boiss. and collected throughout the Turkey, have been intensively studied by using light (LM) and a scanning electron (SEM) microscopy. The objectives of this study are to investigate the pollen morphologies of twenty-one taxa of Turkish Salvia (nine of which are endemic) and to present similar and different characteristics of the taxa. The investigated whole pollen grains had a structure of both isopolar and radial symmetry. Overall, types of aperture were mostly hexacolpate, but it was also determined that the aperture type of S. viridis was both hexacolpate and octacolpate. The pollen grains had characteristic shapes of spheroidal, suboblate, prolate and subprolate. The exine ornamentation was bireticulate and reticulate-perforate. It was determined by the results of palynological studies that pollen morphology changed amongst these studied taxa. As a conclusion, the results of the present study show that palynological characters such as pollen shape, polar axis length (P), equatorial axis length (E), aperture numbers and types and exine ornamentation, exhibit remarkable differences amongst the studied taxa.

The external pollen morphology of Helianthemum caput-felis Boiss. (Cistaceae) was studied from nine populations covering the whole distribution range in the western Mediterranean Basin, using light and scanning electron microscopy. Pollen grains are medium sized, radially symmetrical and tricolporate, and the pollen shape varies from sub-prolate to prolate-spheroidal. According to the exine ornamentation, three main pollen subtypes were recognised: striato-microperforate, microreticulate and rugulato-microperforate. The pollen data demonstrate that the populations of North Africa, as well as one population of the Spanish island of Majorca (Sa Ràpita), show similar micro-reticulate exine ornamentation. The other Spanish populations of Alicante, Colònia de Sant Jordi (Majorca), as well as those of the Italian area of Capo Mannu (Sardinia), show a striato-microperforate pollen type, while the population of Su Tingiosu (Sardinia) shows a rugulato-microperforate pollen type. The different characteristics of the exine ornamentation make it a valuable parameter to distinguish the different populations in the distribution range. Our results suggest an evolutive differentiation by the geographical isolation of the species within the Mediterranean Basin. [ABSTRACT FROM AUTHOR]

The palynomorphology of 19 modern species of the genus Quercus L. native to Armenia and adjacent regions, including the Caucasus and Transcaucasia, the Mediterranean region (especially Turkey), as well as Iran, Iraq and Afghanistan, was studied using light microscopy (LM) and scanning electron microscopy (SEM). The work revealed two main types of apertures (3-zonocolpate, 3-zonocolp-porate) as well as six morphological types of pollen based on three main types of exine ornamentation (tuberculate, verrucate, rugulate). We suggest that two main groups of exine ornamentation developed from a common initial type. The first group covers all species of the subgenus Quercus and also Q. suber and Q. alnifolia of the subgenus Heterobalanus. The second group is limited to the morphological type Q. ilex (species Q. ilex, Q. coccifera, subgenus Heterobalanus). On the other hand, the presence of widespread interspecific and introgressive hybridization within the genus Quercus indicates an ongoing process of speciation. This also has an effect on pollen features, which are very similar in a number of species but also vary in individual samples even within the same species. The morphological uniformity of the pollen surface (especially for the subgenus Quercus), the presence of islets of secondary sporopollenin on the surface of pollen grains, as well as orbicules in anthers, do not indicate general primitiveness of representatives of this genus but most likely denote a relatively high degree of speciation activity within this group. [ABSTRACT FROM AUTHOR]

The genomic constitution of the genus Ophioglossum is complicated because of its being geologically ancient and of long evolutionary history. A lot of plants of the same and different species resemble each other as well as show significant differences among morphological characters among themselves. Many of the new species described have exhibited several unknown features not observed in any species of the genus so far. In this paper, we wish to emphasize that mere observations on shape and size of trophophyll (leaf) and rhizome, should not be taken reliably in delimiting different species of the genus Ophioglossum because of several variations already reported for many species. Preference should be given to exine ornamentation of spores as emphasized by the present study. Detailed observations on exine ornamentation of spores under SEM have offered precious and distinctive features; semi-tuberculate, beaded strings, and stripped exines are a few forms of spore ornamentations offering clear distinction among species. Long chains of circulate-alete (round alete) spores, sometimes linear tetrads as described hereunder in Ophioglossum aletum are novel features exclusively confined to this species. Comparative chromosome profiles of many species described earlier do not offer any significant support to the identity except in O. eliminatum, which has the lowest chromosome count (n = 90). This appears that since almost all species possess intraspecific polyploidy, the intragenomic variability must be loaded with interspecific hybridization contents including chromosomal aberrations. Quite possibly, this may be one of the reasons that homologous chromosomes rarely form trivalents and multivalents during early meiotic stages, despite the fact that palaeoautoploidy must have resulted in copying homologous chromosomes. In recent years, repeated phylogenetic analysis of chloroplast rbcL have revealed that many species in India appear to be offshoots of a vulgatum clade which are likely to be the hybridization products involving O. costatum, O. vulgatum, O. reticulatum, and also including of other interspecific hybridizations. It is remarkable to mention that some of the new taxa published by us, viz. O. eliminatum, O. indicum, O. aletum and O. chalonerii (unpublished), explicitly show distinct phylogenetic relationship maintaining independent genomic identity. Furthermore, each new species shows some rare uniquely confined trait not possessed by any other species of the genus. These morphological traits also suggest that the plants may be expressing extremely rare genic-combinations which might have been brought forth due to autopolyploidy and/or allopolyploidy (hybridizations) during the past few decades. Obviously, we will need a multidisciplinary approach (morphological, anatomical, biochemical) in order to identify different species of Ophioglossum with new and unusual genomic identity and also to understand possible evolutionary mechanisms undergoing within the genome. [ABSTRACT FROM AUTHOR]

A cogent medicinal and aromatic plant, Ziziphora clinopodioides (Lamiaceae) is a perennial herb, its aerial parts is used as a wild vegetable or additive in foods to proffer pleasant aroma and flavour. There are many discussions about the intraspecific classification of this species and several subspecies have been introduced for it in different flora. These subspecies are morphologically very similar and identification of them is very difficult and in some cases, impossible. Therefore, in the present study, the pollen grains morphology of nine subspecies (32 specimens) of Z. clinopodioides were probed and documented in details utilising the scanning electron microscopy (SEM). In total, eleven pollen morphological characteristics were investigated and analysed by PAST software. The obtained results showed that pollen grains were hexacolpate and their equatorial views were sub-oblate to prolate. The exine ornamentation types of the pollen grains are bireticulate, microreticulate, reticulate and bireticulate-reticulate. The ANOVA test did not show significant difference for the studied quantitative traits. Although, the results of the multivariate analysis revealed a high diversity amongst the specimens even in the specimens of a single subspecies; it did not confirm the separation of subspecies in Z. clinopodioides. [ABSTRACT FROM AUTHOR]

• The current study gives a first-hand report on the palynological variation of wild Cannabis populations of the western Himalaya, India. • Pollen grains of 55 accessions across the western Himalayan region were studied. • Tetraporate pollen were first time reported in genus Cannabis. • Significant variation in pollen characters such as pollen size, aperture number, and surface ornamentation was found. The present study aimed to examine the intraspecific variation in pollen traits of genus Cannabis from Western Himalaya, India. A total of 1650 pollen grains from 55 accessions collected from an altitudinal range between 259 and 2751 m a.s.l from the western Himalayas, India were analyzed by (LM) light microscopy and (SEM) Scanning Electron Microscopy. Six quantitative characters, i.e., length of the polar axis (P), length of equatorial axis (E), exine thickness (Ex), number of granules (Ng), pore diameter (Pd), and P/E ratio were studied. Pollen grains of maximum accessions were tricolpate while pollen grains of three accessions i.e., CAN17, CAN25 and CAN31 were tetraporate. Majority of the pollen grains were prolate spheroidal (83.64%) whereas 1.82% was spheroidal. PCA indicated that the first four components account for 69.9% of the total variability. PC1 attribute 34.41% of the variability with equatorial diameter being the significant variable, whereas PC2 contributed 19.57% variability having length of polar axis (P) and shape class (P/E) as the significant variables. PC3 contributed 20.1% of the total variability with PE and number of granules being the significant variables. Pollen size, aperture number, and surface ornamentation may prove useful in species discrimination. This current study gives a first-hand report on the palynological variation of wild Cannabis populations of the Western Himalaya, India. [ABSTRACT FROM AUTHOR]

The genus Centaurea L. is one of the largest genera in the family Asteraceae. The number of taxa included in this genus ranges from 500 to 600 worldwide. Iran is one of the major centers of diversity for this genus. Pollen morphology has proved useful in the systematics of Asteraceae, as well as in that of some of its genera and species. The pollen morphology of 19 taxa of the genus Centaurea was investigated in detail by light and scanning electron microscopy. Examination under light microscopy showed pollen grains to be tricolporate, isopolar, radially symmetrical, oblate spheroidal, prolate spheroidal, subprolate, tectum perforate and scabrate. Based on the exine ornamentation observed under scanning electron microscopy, we identified two types of pollen grains, designated type I (dense acute spinules) and type II (sparse spinules). All of the taxa evaluated resemble Wagenitz's Jacea type. We present micrographs of pollen grains, together with descriptions of the characteristics of their structure. We found that the pollen characters (shape, exine structure, sculpturing) were useful for classification.

The paper presents pollen micromorphology by scanning electron microscopy of seven Anabasis L. species namely, A. haussknechtii Bge., A. aphylla L., A. calcarea (Charif & Allen) Bokhari & Wendelbo, A. eugeniae Iljin, A. eriopoda (Shrernk) Volkens, A. annua Bge. and A. setifera Moq. from Iran. Pollen grains in all studied species are peripolyporate, spherical and are of two basic types based on pores diameter inner of holes. The study showed that the sculpturing of exine provides valuable characters in species delimitation, sometimes even for closely related ones. An artificial key based on pollen characters for seven species is provided. [ABSTRACT FROM AUTHOR]

The wall of pollen grains exhibits morphological variation in many features including apertures, ornamentation and thickness, but the function of these characters remains to be clarified. It has been suggested that they are involved in the accommodation of volume changes (harmomegathy). To investigate this further, we developed a protocol that induces a controlled hydration of the pollen without affecting its metabolism and we applied it to six species differing in their pollen wall morphology. The entry of water caused pollen swelling and volume increase leading to breakage of the wall and/or of the plasma membrane, such that the per cent of intact grains was negatively correlated with the level of hydration. Qualitative and quantitative differences were observed between the species. Breakage of the exine was observed only in pollen lacking apertures and with thin exine. Variation in the exine ornamentation and thickness could explain the interspecific differences observed for the rates of breakage of the plasma membrane. Our results suggest that pollen wall morphology matters for survival and maintenance of pollen integrity further to volume increase due to hydration. We propose a rationale for future studies that should allow disentangling the contribution of different pollen morphological and physiological features to harmomegathy. [ABSTRACT FROM AUTHOR]

The purpose of this study conducted to know variety of : long of axis polar, equatorial plane diameters, and P/E index of ten Kembang Sepatu (Hibiscus rosa-sinensis L.) with differnt colour flowers. Acetolysis method and 1 % Safranin staining used to make pollens slides, micrometri were used to measured long of polar axis and diameter of pollens. The result of this research showed : pollen structure have: 90,10 ± 3,02 ^im to 117,42 ± 1,37 l^m axis polar long, 89,66 ± 3,13 |^m to 112,92 ± 0,94 (xm equatorial plane diameter, and 0,99 to 1,04 P/E index. Based on these data is indicated that the type of the pollen are prolat sferoidal (except bud type red corolla, and white flower) polypantoporat type appertura and periporat ornamentation exine .

The pollen grains of several gymnosperm groups consist of a main body and one to three air-filled bladders, or sacci. Although sacci may serve a buoyancy function to orient the grain on the ovular pollination droplet in some taxa, sacci have also been shown to increase pollen volume while adding minimal mass, thus decreasing density and thereby increasing the aerodynamic efficiency of wind pollination. However, no published studies have quantitatively addressed the effects of grain geometry or surface ornamentation at the low Reynolds numbers that pollen grains demonstrate. The objectives of this study were to empirically investigate the effects of varying geometries and surface ornamentation on the aerodynamic properties of saccate pollen grains through the experimental determination of drag coefficients and shape factors. Structurally different grains of two extant conifers (Pinus and Falcatifolium) were studied, and using electron microscopy, mathematical modeling, and solid modeling, we created scaled-up physical models of the pollen types. Models were produced with and without sacci, as well as with and without surface texture on the main body. Sacci increased the shape factor, or resistance coefficient, in all pollen types studied, compared to the same types that had been modeled without sacci. The presence of surface ornamentation also decreased the drag coefficients for saccate pollen grains of Pinus. This study is the first to experimentally demonstrate the effect of surface texture on drag for any biological or nonbiological particle at low Reynolds numbers. This study also provides additional empirical evidence for the aerodynamic role of sacci, supporting their adaptive significance for anemophily. [ABSTRACT FROM AUTHOR]

In this study, pollen morphology of 11 taxa of Hosta in China , three Chinese species, five introduced species, and three cultivars, was observed by scanning electron microscopy (SEM) and compared with that of related genera ( Hemerocallis, Agave, and Yucca). Pollen grains of Hosta were long-ellipsoidal or ellipsoidal, 20-65 × 52.5-142.5 μm in size, bilaterally symmetrical, and monosulcate on the distal face. Reticulate and rugulate exine ornamentation was observed in different taxa, and the rugulate type can be further divided into rugulate, rugulate-baculate, and rugulate-granulate subtypes. The exine ornamentation may have evolved in the order: reticulate → rugulate → rugulate-baculate → rugulate-granulate. Furthermore, the rugulate exine ornamentation was the predominant ornamental type in Hosta except for one species with the reticulate type; this is markedly different from that of Hemerocallis, Agave and Yucca. Thus, our data support the proposal by Dahlgren and Clifford (The Monocotyledons: a comparative study. Academic Press, London, ) that these Hosta species constitute an independent family-Hostaceae. [ABSTRACT FROM AUTHOR]

Abstract: Pollen grains of 30 taxa of the genus Salvia, belonging to sections Salvia, Horminum, Drymosphace, Plethiosphace and Hemisphace from Turkey were examined by light (LM) and scanning electron microscopy (SEM). Detailed pollen morphological characteristics are provided for these taxa. Among the studied taxa, S. verticillata subsp. verticillata from sect. Hemisphace has the smallest pollen grains, and S. pachystachys from sect. Salvia possesses the largest ones. The basic shape of the pollen grains in most taxa is suboblate, oblate–spheroidal or prolate–spheroidal. However subprolate pollen grains are recorded for S. macrochlamys from sect. Salvia. The grains are hexacolpate in all taxa, but in S. recognita from sect. Salvia also octacolpate pollen was found. Three distinct exine sculpturing types exist, reticulate–perforate (the common type), reticulate–granulate and bireticulate. The reticulate–perforate and bireticulate sculpturing patterns can be divided into subtypes based on the number of perforations and the number of secondary lumina in each primary lumen. Pollen morphological characteristics of the taxa studied are compared and discussed on the basis of taxonomical concepts. In some cases, these characters are useful in distinguishing the sections. For instance, the presence of 1–2 large central secondary lumina per primary lumen is a significant character of sect. Horminum separating it from the other sections. As well, the presence of holes on colpus membrane ornamentation can be used as a diagnostic taxonomic character for sectional division between sect. Hemisphace and others. S. ballsiana from sect. Salvia is clearly distinct from the other taxa examined by its unique pollen morphology. Further, for several macromorphologically similar taxa pollen structures provide additional evidence to delimite them from each other. [Copyright &y& Elsevier]

A morphometrical study of pollen grains using scanning electron microscopy was performed in seven genera belonging to subtribe Artemisiinae (Anthemideae). Forty-six populations representing 40 species were considered, mainly from the genus Ajania (31 populations studied of 25 species). This work also includes observations on the genera Brachanthemum, Cancrinia, Crossostephium, Dendranthema, Elachanthemum, Hippolytia, Kaschgaria, Poljakovia and Stilpnolepis. Most data presented here constitute the first pollen observation for some species and genera ( Cancrinia and Poljakovia). Two different pollen exine ornamentations are confirmed for the tribe, Anthemis-type (echinate) and Artemisia-type (microechinate), a result consistent with previous studies. The Artemisia-type is exclusive to the subtribe, whereas the Anthemis-type is found present outside Artemisiinae, suggesting that it may represent the ancestral character state for the group. These pollen types appear to be clearly differentiated on the basis of their size and exine ornamentation. Their phylogenetic distribution in Artemisiinae also generally segregates them: the Anthemis-type is found in Dendranthema and allied genera, whereas the Artemisia-type occurs in Artemisia and closely related genera. However, we found some very rare exceptions to this trend (e.g. Ajania junnanica, Elachanthemum and Stilpnolepis), the possible origins of which are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 171–189. [ABSTRACT FROM AUTHOR]

The pollen morphology of subtribe Menthinae sensu Harley et al. [In: The families and genera of vascular plants VII. Flowering plants·dicotyledons: Lamiales (except Acanthaceae including Avicenniaceae). Springer, Berlin, pp 167–275, ] and two genera of uncertain subtribal affinities ( Heterolamium and Melissa) are documented in order to complete our palynological overview of the tribe Mentheae. Menthinae pollen is small to medium in size (13–43 μm), oblate to prolate in shape and mostly hexacolpate (sometimes pentacolpate). Perforate, microreticulate or bireticulate exine ornamentation types were observed. The exine ornamentation of Menthinae is systematically highly informative particularly at generic level. The exine stratification in all taxa studied is characterized by unbranched columellae. Orbicules are consistently absent in Menthinae. Our palynological data are interpreted in a phylogenetic context at tribal level in order to assess the systematic value of pollen characters and to evaluate the existing molecular phylogenies for this group. Pollen morphology suggests Heterolamium as a close relative of subtribe Nepetinae and supports the molecular affinity of Melissa to subtribe Salviinae. [ABSTRACT FROM AUTHOR]

Along with a significant variety of the apertural types of pollen grains, the family Solanaceae is allocated also with the variety of types of the exine ornamentation. Pollen grains of 55 species from 42 genera of the family Solanaceae have been examined with the help of a scanning electronic microscope (SEM). Eight simple types of the sculpture have been established: scabrate, granulate, tuberculate, plicate, echinate, striate, reticulate and the sculpture with the excrescences. Three other sculptural types - verrucate, perforate-tectate and foveate have been resulted from the references. The comparative analysis of simple sculptural types within the limits of the separate subfamilies of the family Solanaceae has been carried out. [ABSTRACT FROM AUTHOR]

Pollen morphology in ten plants of F 2 progeny of an interspecific tree hybrid, Chorisia insignis H. B.& K.× C. speciosa St. Hil (Bombacoideae, Malvaceae) has been studied with a view to have an insight in to the effect of hybridization on the pollen morphological features in F 2 generation. The study is a sequel to an earlier study on the pollen morphology of Chorisia species and their F 1 hybrid, in which case the hybrid pollen uniformly exhibited the apertural features of the male parent and exine features of the female parent. In the F 2 progeny the pollen grains display the apertural feature of the male parent in all the plants. However, with regard to exine ornamentation, variability has been observed. Of the ten plants, two plants exhibit the exine features of the male parent showing empty lumina (without bacula), five plants have their pollen exactly like that of the F 1 plant (showing prominent columellar heads in the lumina of the apocolpium region) and the remaining three plants showing columellae in lumina of both apocolpium and mesocolpium region being different from the above types. It has been inferred that the variability in the exine pattern in F 2 pollen indicates that the pollen exine pattern in hybrids, perhaps, is not unequivocally controlled by sporophytic or gametophytic genomes. [ABSTRACT FROM AUTHOR]

This study assesses to what extent bat pollination has acted as a selective force on pollen morphology. Earlier pollen studies have suggested convergent evolution of verrucate exine ornamentation. Furthermore pollen of bat pollinated plants has been reported to be bigger than that of plants pollinated by other means. The generality of these ideas is tested using a sample of 130 species of both bat pollinated plants and relatives with another mode of pollination. An analysis of pollen size, shape, aperture number and type, and ornamentation type of 35 plant groups in which a transition towards bat pollination occurred was performed and showed a significant effect for pollen size only. Bat pollinated plants have bigger pollen than their relatives. Pollen size was shown to correlate with style length. Pollen shape, aperture system and exine ornamentation are in general not very different in bat pollinated plants in comparison with their relatives. There is no consistent trend for rougher exines to be associated with bat pollination. [ABSTRACT FROM AUTHOR]