Some dicotyledonous pollen types from Cainozoic deposits in the Australian region

1954 ◽  
Vol 2 (2) ◽  
pp. 197
Author(s):  
IC Cookson ◽  
KM Pike
Keyword(s):  
Pollen Grains ◽  
Australian Region ◽  
Pollen Types ◽  
Living Species

Pollen types referable to the families Casuarinaceae, Haloragaceae,Myrtaceae, Olacaceae, Proteaceae, Santaiaceae, and Sapindaceae have been described from Cainozoic deposits in the Australian region; their relationship to living species has been discussed wherever possible. The characters and distribution of three sporomorphs of uncertain affinity have been considered. Details concerning the pollen grains of some of the living species of Anacolosa, Cathedra, Casuarina, the tribe Cupanieae (Sapindaceae), Haloragis, Myriophyllurn, and Santalurn have been recorded.

A contribution to the tertiary occurrence of the genus Dacrydium in the Australian region

1953 ◽  
Vol 1 (3) ◽  
pp. 474 ◽  
Author(s):  
IC Cookson ◽  
KM Pike
Keyword(s):  
Pollen Grains ◽  
New Guinea ◽  
Fossil Pollen ◽  
Australian Region ◽  
Living Species

Foliage shoots and seeds of a new Tertiary species, Dacydium rhomboideum, are described; the affinity of D. rhomboideum is discussed.A new sporomorph, Dacrydiumites florinii, is proposed for fossil pollen grains, similar to those of certain species of Dacrydium, isolated from Tertiary deposits in Australia, Tasmania, and New Guinea. Descriptions of the pollen grains of the living species Dacrydium araucurioides and Dacrydium balansae are included.

Pollen Taphonomy in a Canyon Stream

1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall
Keyword(s):  
Surface Soil ◽  
Pollen Grains ◽  
Close Correlation ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Arid Steppe ◽  
Turbulent Water

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

The Use of Ecological Tolerances for the Reconstruction of Tertiary Palaeoclimates

1997 ◽  
Vol 45 (3) ◽  
pp. 475 ◽  
Author(s):  
Helene A. Martin
Keyword(s):  
Vegetation Types ◽  
Climatic Parameters ◽  
Salt Tolerant ◽  
Pollen Assemblage ◽  
Pollen Types ◽  
Living Species ◽  
Marine Influence ◽  
Lagarostrobos Franklinii ◽  
Single Living ◽  
Very High

The major vegetation types may be recognised from the pollen assemblage being deposited beneath them, hence the palaeovegetation may be reconstructed from fossil pollen assemblages. The climatic parameters of the vegetation may then be used to reconstruct palaeoclimates. The result, however, is very general. Most pollen types can only be affiliated with a family, a genus or a group of species and the ecological tolerances within these groups may not be uniform. There are, however, some distinctive pollen types that can be identified with a single living species and this paper examines the potential of these types in the reconstruction of palaeoclimates. Lagarostrobos franklinii (J.D.Hook) Quinn, Huon pine, has a long history and the fossil occurrences of it are compatible with the hypothesis that its ecological tolerances have not changed and it has always required very high humidity. Two sclerophyllous taxa,Eucalyptus spathulata Hook. and Dodonaea triquetra Wendl., however, coexisted with rainforest and then other vegetation types as the climate became drier, adapting to the prevailing conditions. The evidence suggests that the salt-tolerant E. spathulata may have evolved in small patches of coastal scrub, subjected to marine influence, within the dominant rainforest vegetation.

scholarly journals Airborne pollen observations using a multi-wavelength Raman polarization lidar in Finland: characterization of pure pollen types

2020 ◽  
Author(s):  
Xiaoxia Shang ◽  
Elina Giannakaki ◽  
Stephanie Bohlmann ◽  
Maria Filioglou ◽  
Annika Saarto ◽  
...  
Keyword(s):  
Optical Properties ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
Wavelength Dependence ◽  
Depolarization Ratio ◽  
Mean Values ◽  
Pollen Types ◽  
Pine Pollen ◽  
Significant Wavelength ◽  
532 Nm

Abstract. We present a novel algorithm for characterizing the optical properties of pure pollen particles, based on the depolarization values obtained in lidar measurements. The algorithm was first tested and validated through a simulator, and then applied to the lidar observations during a four-month pollen campaign from May to August 2016 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio (62°44′ N, 27°33′ E), in Eastern Finland. Twenty types of pollen were observed and identified from concurrent measurements with Burkard sampler; Birch (Betula), pine (Pinus), spruce (Picea) and nettle (Urtica) pollen were most abundant, contributing more than 90 % of total pollen load, regarding number concentrations. Mean values of lidar-derived optical properties in the pollen layer were retrieved for four intense pollination periods (IPPs). Lidar ratios at both 355 and 532 nm ranged from 55 to 70 sr for all pollen types, without significant wavelength-dependence. Enhanced depolarization ratio was found when there were pollen grains in the atmosphere, and even higher depolarization ratio (with mean values of 25 % or 14 %) was observed with presence of the more non-spherical spruce or pine pollen. The depolarization ratio at 532 nm of pure pollen particles was assessed, resulting to 24 ± 3 % and 36 ± 5 % for birch and pine pollen, respectively. Pollen optical properties at 1064 nm and 355 nm were also estimated. The backscatter-related Ångström exponent between 532 and 1064 nm was assessed as ~ 0.8 (~ 0.5) for pure birch (pine) pollen, thus the longer wavelength would be better choice to trace pollen in the air. The pollen depolarization ratio at 355 nm of 17 % and 30 % were found for birch and pine pollen, respectively. The depolarization values show a wavelength dependence for pollen. This can be the key parameter for pollen detection and characterization.

A study on the pollen morphology of the genus Combretum Loefl. and its taxonomic significance

2016 ◽  
Vol 6 (4) ◽  
pp. 131-142
Author(s):  
Gamal E. B. E.B. El Ghazali
Keyword(s):  
Pollen Grains ◽  
Polar View ◽  
Taxonomic Revision ◽  
Molecular Classification ◽  
Ecological Indicator ◽  
Wide Range ◽  
Pollen Types ◽  
Specific Variation ◽  
Palynological Study

Pollen grains of 92 species (from 99 collections) belonging to the genus Com-bretum (Combretaceae) were examined by Light Microscope (LM) and Scan-ning Electron Microscope (SEM). These species are representatives of vari-ous taxa outlined in the latest taxonomic revision of the genus. The genus belongs to a tropical or subtropical family, frequently encountered in various Quaternary deposits and acts as ecological indicator in various habitats. Pol-len grains of all members of the genus Combretum examined are hetero-colpate (with three simple apertures alternating with three composite ones) and exhibited wide range of inter-specific variation with respect to polar axes (P), Equatorial diameters (E), P/E ratios, shape classes, shape in polar view, costae pori, vestibula, protrusion of endoapertures and exine sculptur-ings. Species delimitation in these nine characters is tabulated. Four shape classes, eight exine sculpturings and seven pollen types were recognized. A key for identification to these pollen types is presented and the species in-cluded in each of these types are also outlined. Previous macro-morphological and molecular classification of the genus were discussed in the light of the present palynological study.

Sporoderm morphogenesis in Euphorbia obesa and Croton gratissimus

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 849-856 ◽  
Author(s):  
M. L. Frean
Keyword(s):  
Pollen Morphology ◽  
Pollen Grains ◽  
Physiological Adaptation ◽  
Structure Characteristic ◽  
Pollen Type ◽  
Electron Microscope Level ◽  
Pollen Characters ◽  
Pollen Types ◽  
Unisexual Flowers ◽  
Taxonomic Grouping

Pollen grains of the Euphorbiaceae show a number of pollen types which can be clearly distinguished. Generally different genera are characterized by a specific pollen type.  Euphorbia obesa Hook. f. and Croton gratissimus Burch, subsp.  subgratissimus (Prain) Burtt Davy, represent two genera within the Crotonoideae with different morphology, each type characteristic for the respective genus. Taxonomically, the genus Euphorbia with apetalous flowers consisting of a naked pistil surrounded by several staminate flowers within a cyathium, is considered more advanced than the genus  Croton. In  Croton the inflorescence is a raceme with unisexual flowers. The floral whorls of the male show numerous anthers and both calyx and a showy corolla are present. Both genera are insect pollinated. In both  Euphorbia obesa and  Croton gratissimus the pollen wall in section shows columellae, a structure characteristic of angiosperms. However the present ontogenetic studies show that the formation of the columellae differs entirely in the two pollen types. The final stratification of the wall as well as the morphology of the grains differ and evaluation of the exine structure indicates that phylogenetically Croton pollen shows more advanced characters than  Euphorbia — contradicting the floral phylogeny. This study conducted at light and electron microscope level compares the two pollen types morphologically and ontogenetically, concentrating mainly on the formation of the exine which is tectate-perforate in the prolate tricolpate grain of Euphorbia obesa and semi-tectate in the anaperturate, spheroidal grain of Croton gratissimus. The aim of the study was to evaluate the significance of pollen characters in taxonomic and phylogenetic relationships within the Euphorbiaceae. The differing pollen morphology which is related to the taxonomic grouping of tribes within the subfamily (Crotonoideae) emphasizes diversity, which may result from physiological adaptation. The study shows that the same functional end may well be achieved in different ways and this may be a factor underlying the diversity in the heterogeneous family Euphorbiaceae.

scholarly journals Precise Pollen Grain Detection in Bright Field Microscopy Using Deep Learning Techniques

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3583 ◽  
Author(s):  
Ramón Gallardo-Caballero ◽  
Carlos J. García-Orellana ◽  
Antonio García-Manso ◽  
Horacio M. González-Velasco ◽  
Rafael Tormo-Molina ◽  
...  
Keyword(s):  
Network Architecture ◽  
Detection System ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Average Value ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Pollen Counting ◽  
Estimation System ◽  
3D Information

The determination of daily concentrations of atmospheric pollen is important in the medical and biological fields. Obtaining pollen concentrations is a complex and time-consuming task for specialized personnel. The automatic location of pollen grains is a handicap due to the high complexity of the images to be processed, with polymorphic and clumped pollen grains, dust, or debris. The purpose of this study is to analyze the feasibility of implementing a reliable pollen grain detection system based on a convolutional neural network architecture, which will be used later as a critical part of an automated pollen concentration estimation system. We used a training set of 251 videos to train our system. As the videos record the process of focusing the samples, this system makes use of the 3D information presented by several focal planes. Besides, a separate set of 135 videos (containing 1234 pollen grains of 11 pollen types) was used to evaluate detection performance. The results are promising in detection (98.54% of recall and 99.75% of precision) and location accuracy (0.89 IoU as the average value). These results suggest that this technique can provide a reliable basis for the development of an automated pollen counting system.

scholarly journals Pollen spectrum of Finnish honey 

1982 ◽  
Vol 54 (5) ◽  
pp. 403-420
Author(s):  
Anna-Liisa Varis ◽  
Juha Helenius ◽  
Kari Koivulehto
Keyword(s):  
Agricultural Practices ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Pollen Spectrum ◽  
Dominant Type ◽  
Oilseed Crops ◽  
Pollen Types ◽  
Average Proportion ◽  
Total Pollen ◽  
Salix Spp

Pollen spectra were analysed on 160 honey samples representing the whole beekeeping area of Finland in the years 1977 and 1978. A semi-quantitative method of pollen analysis based online counts was developed. It was found efficient for determining the relative numbers of pollen grains in the honey samples. On average, ca. 16 pollen types were identified per sample. The number of honeydew elements was low in all samples. Brassicaceae pollen was the dominant type. The other most frequent and abundant types were pollen grains of Trifolium repens + T. hybridum, Salix spp., "the Rosaceae group” (Prunus, Malus, Sorbus spp.), Apiaceae, and Filipendula ulmaria. These pollen types constituted 90.8 % (1977) and 90.3 % (1978) of all the pollen examined. Between 1960—1963 and 1977—1978 the average proportion of Brassicaceae pollen has risen, while the proportion of T. repens + T. hybridum pollen has decreased, evidently due to the changes in agricultural practices. The seasonal variation in the pollen spectrum was explained by the weather conditions. Regionally characteristic pollen spectra were not found, although Brassicaceae pollen was typical of the honeys of agricultural zones I and II, due to cultivation of Brassica oilseed crops in those regions. The positive correlation of the proportion of Brassicaceae pollen with the total pollen count is discussed in connection with the problem of determining the botanical origin.

scholarly journals Palynological analysis of genus Geranium (Geraniaceae) and its systematic implications using scanning electron microscopy

Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 31-43
Author(s):  
Jun Wang ◽  
Qiang Ye ◽  
Tong Zhang ◽  
Xusheng Shi ◽  
Majid Khayatnezhad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Grains ◽  
Prolate Spheroid ◽  
Multivariate Statistical ◽  
Pollen Characters ◽  
Pollen Types ◽  
Ward Clustering ◽  
The Relationship ◽  
Scanning Electron

Pollen morphology of 23 species belonging to Geranium have been studied in details, which represent eight sections of two subgenera i.e., G. sect. Dissecta, Geranium, and Tuberosa of subgen. Geranium, Divaricata, Lucida, Ruberta and Trilopha of subgen. Robertium. These plant species were collected from different phytogeographical regions of Iran. The palynological investigation was done using scanning electron microscopy (SEM) techniques. Different palyno-morphological features have been observed, and the closely related species were distinguished. We used different multivariate statistical methods to reveal the species relationships. Ward clustering analyses have been done to check out the relationship among the species. The shapes of pollen grains were monad, radially symmetric, isopolar, apertures were tricolporate, and of spheroid, prolate-spheroid or sub-prolate classes. Three pollen types were recognized on the basis of differences in exine sculpturing pattern: reticulate-clavate, striate-rugulate, reticulum cristatum with clavae. Observed differences were not of diagnostic importance in subgenera and sections level. The main objective of this study is to find distinguish pollen characters in the species of the genus Geranium and to elucidate their systematics importance.

scholarly journals Palynological characterization of honey samples from Kwara State, Nigeria

2017 ◽  
Vol 52 (1) ◽  
pp. 7-14
Author(s):  
SD Oyeyemi ◽  
J Kayode
Keyword(s):  
Pollen Grains ◽  
Species Level ◽  
Palynological Analysis ◽  
Genus Level ◽  
Pollen Types ◽  
Family Level

Palynological analysis of honey samples from different localities in Kwara State, Nigeria was carried out to isolate and identified pollen types in the honey samples. Out of forty two pollen types belonging to twenty two botanical families recovered, twenty five were identified to species level, eight to genus level and eight to family level. A total of 849,978 pollen grains were counted with 46,355 in Shao, 101,356 in Ganmo, 22,000 in Idofian, 28,337 in Omupo, 200,090 in Iludun Oro, 298,079 in Ijagbo, 22,100 in Offa I and 131,142 in Afon. The major pollen occurrences in the honey samples include those of Sarcocephaluslatifolius, Parkiabiglobosa, Phyllantusdiscoideus, Tridaxprocubens, Combretaceae/Melastomataceae, Spondiasmombins and Hymenocardiaacida. Other important honey plants identified are Elaeisguineensis, Lanneasp, Parinarisp, Celtissp and Entadaabssynica. All these are characteristic plant taxa of the Forest-Savanna ecotype of the studied area. The presence of relatively high quantity of pollen shows their richness in pollen composition and also a clear evidence that the honey are from botanical sourceand also multifloral.Bangladesh J. Sci. Ind. Res. 52(1), 7-14, 2017

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