Results 81 to 90 of about 31,308 (299)
Palynological study of some species in Grumorsae group of the genus Ranunculus in Iran
تاکسونومی و بیوسیستماتیک, 2014 In this research, pollen grains of some species of Grumorsae group of Ranunculus were studied. In doing so, pollen grains of 13 species were studied by light microscope and the surface of nine pollen grains has studied by Scanning Electron Microscope ...
Maneezheh Pakravan +2 more
doaj
Acta Botânica Brasílica, 2018 Heteranthery, the presence of different types of stamens in a flower, may reduce the conflict between pollinators and plants by ensuring the resource for the pollinator without drastically affecting the availability of viable male gametes for ...
Bruna Karen Pinheiro-Costa +3 more
doaj +1 more source
Journal of Quaternary Science, EarlyView.ABSTRACT The northern European distal cryptotephra framework is constantly developing both in terms of identification of new tephra horizons and improved age constraints for the already well‐established tephra marker horizons. However, many prehistoric tephra layers have only been dated by the radiocarbon method, with its inherent problems.
Maarit Kalliokoski +2 more
wiley +1 more source
Botanical StudiesThe pollen dispersal unit of the epidendroid species, Cephalanthera longifolia, is a soft pollinium consisting of loosely connected tetrads that are agglutinated by elastoviscin.
Carola Purgina +2 more
doaj +1 more source
Environmental Research Letters, 2013 Pollen taxon in sediment samples can be identified by analyzing pollen morphology. Identification of related species based on pollen morphology is difficult and is limited primarily to genus or family.
Fumio Nakazawa +8 more
doaj +1 more source
Anais da Academia Brasileira de Ciências, 2013 The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen ...
Saulo M. Sousa +4 more
doaj +1 more source
Journal of Quaternary Science, EarlyView.ABSTRACT Victoria Cave, north Yorkshire, England, contains a long sequence of Pleistocene clastic sediments and calcite flowstones. Earlier work, using U–Th dating, established that the flowstone units formed in interglacial stages corresponding to Marine Isotope Stages (MIS) 13, 11, 9, 7 and 5.
Tom C. Lord +7 more
wiley +1 more source
Morphology and contents of mature pollen grains.
, 2014 Mature pollen grains are suboblate to spheroidal, isopolar, radially symmetrical and 3-porate. A prominant globular protruding oncus projects from each aperture. For most of their development, the pollen grains do not contain starch grains.
Abraham E. van Wyk (154306) +2 more
core +1 more source
Pollen morphology of Curroria, Mondia, Socotranthus and Stomatostemma (Periplocaceae)
Bothalia: African Biodiversity & Conservation, 1993 The pollen morphology of I Planch., O Skeels, Socotranthus Kuntze and Stomatostemma N.E. Br. was studied.All the genera are characterized by pollen grains arranged in tetrads. The arrangement of the grains may be rhomboidal, tetrahedral or decussate. The
R. L. Verhoeven, H. J. T. Venter
doaj +1 more source