scholarly journals Pollen of the Spermacoce (Rubiaceae) species from the Northern Territory of Australia: morphology and taxonomic significance

2005 ◽  
Vol 18 (4) ◽  
pp. 367 ◽  
Author(s):  
S. Dessein ◽  
R. Harwood ◽  
E. Smets ◽  
E. Robbrecht
Keyword(s):  
Light Microscopy ◽  
Morphological Variation ◽  
Pollen Morphology ◽  
Northern Territory ◽  
Taxonomic Significance ◽  
Equatorial Diameter ◽  
Pollen Characters ◽  
Pollen Types ◽  
Electron And Light Microscopy ◽  
Scanning Electron

Complementary to the revision of the genus Spermacoce in the Northern Territory of Australia, pollen morphology of 48 of the 53 native Spermacoce species from the Northern Territory has been investigated by scanning electron and light microscopy. There is considerable variation for most diagnostic pollen characters. The average equatorial diameter (E) ranges from 10.5 to 41.7 µm. Grains are invariably colporate with the apertures situated at the equator (being zonocolporate). The number of apertures varies from 3 to 17. The endoaperture is generally an endocingulum, often with a secondary thinning at the ectocolpus; one species has endocolpi. The sexine is usually perforate, but psilate, foveolate, and (micro)reticulate patterns were also found. Supratectal elements are present as granules or microspines scattered over the whole surface or confined to a region around the ectoapertures. The inner nexine surface is granular, often with irregular grooves (endocracks). The pollen morphological variation observed allows the distinction of four pollen types. Three of these types are not yet recorded in other palynological studies of Spermacoce. Pollen characters are often useful to delimit species and groups of related species.

scholarly journals THE HEDYOTIS–OLDENLANDIA–KOHAUTIA COMPLEX (RUBIACEAE) IN NEPAL: A STUDY OF FRUIT, SEED AND POLLEN CHARACTERS AND THEIR TAXONOMIC SIGNIFICANCE

2009 ◽  
Vol 66 (3) ◽  
pp. 371-390 ◽  
Author(s):  
S. Neupane ◽  
S. Dessein ◽  
T. J. Motley
Keyword(s):  
Pollen Grains ◽  
Seed Morphology ◽  
Marked Variation ◽  
Taxonomic Significance ◽  
Pollen Characters ◽  
Electron And Light Microscopy ◽  
Seed Characters ◽  
Fruit Dehiscence ◽  
Natural Groups ◽  
Scanning Electron

Pollen and seed characters of 12 Nepalese representatives of the Hedyotis–Oldenlandia–Kohautia complex (Spermacoceae s.l.; Rubiaceae) were investigated morphologically using scanning electron and light microscopy. The members of the complex were found to show remarkable variation in fruit, seed and pollen features. Pollen grains were all colporate with the aperture number varying from 3–4 to occasionally 5. The ectoaperture was a colpus, and the endoaperture was an endocingulum, a lalongate endocolpus or an endocolpus combined with an annulus around the mesoporus. Sexine ornamentation was variable, being perforate, reticulate or microreticulate. Three species were found to have a double reticulum. Supratectal elements were generally absent, but sometimes muri were beset with granules. Seeds were numerous per capsule, small and non-crateriform. Three types of seed were distinguished based on shape: (1) lenticular with a narrow wing-like margin, (2) trigonous, and (3) globose/subglobose. Trigonous seeds exhibited marked variation in colour, size and shape. On the basis of the pollen and seed characters, used in combination with the type of fruit dehiscence, five natural groups are identified for Nepalese taxa. The generic status of Hedyotis, Oldenlandia and Kohautia is maintained but some species are transferred from Hedyotis to Oldenlandia. Pollen and seed morphology, together with the type of fruit dehiscence, proved to be helpful in delimiting supra- and infrageneric groups within the Hedyotis–Oldenlandia–Kohautia complex.

Pollen morphology of Pacific Northwestern Polemonium species in relation to paleoecology and taxonomy

1979 ◽  
Vol 57 (21) ◽  
pp. 2428-2442 ◽  
Author(s):  
Rolf W. Mathewes
Keyword(s):  
Light Microscopy ◽  
Electron Micrographs ◽  
Pollen Analysis ◽  
Pollen Morphology ◽  
Scanning Electron Micrographs ◽  
Taxonomic Treatment ◽  
Close Affinity ◽  
Pollen Types ◽  
Quaternary Paleoecology ◽  
Scanning Electron

Six morphological types of Polemonium pollen are described, including P. micranthum which is the only taxon considered to be consistently identifiable to species. A key to the pollen types as seen in light microscopy is presented along with light and scanning electron micrographs of each type. The palynological evidence supports the taxonomic treatment of P. uciitiflorum and P. occidentale as subspecies of P. caeruleum, and supports a close affinity between P. pectinatum and P. foliosissimum. Brief summaries of the present-day ecology and distribution of Pacific Northwestern Polemonium species are presented. The application of indicator pollen analysis in Quaternary paleoecology is discussed, with special references to examples of paleoenvironmen-tal inference using Polemonium pollen types.

Pollen morphology of the Myrtaceae. Part 4: tribes Kanieae, Myrteae and Tristanieae

2012 ◽  
Vol 60 (3) ◽  
pp. 260 ◽  
Author(s):  
Andrew H. Thornhill ◽  
Geoff S. Hope ◽  
Lyn A. Craven ◽  
Michael D. Crisp
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
The Other ◽  
Pollen Types ◽  
Scanning Electron

Pollen morphology of 44 genera and 101 species from the Myrtaceae tribes Kanieae, Myrteae and Tristanieae was surveyed using scanning electron microscopy (SEM) and light microscopy (LM). Most Myrteae pollen were brevicolpate and granulate, which is unique within Myrtaceae, and these are most likely ancestral characters for this tribe. Two main pollen types were observed in tribe Kanieae, one form being with syncolpate colpi and a distinctive granulate exine, and the other with parasyncolpate colpi and a less ornamented exine. Genera Tristania and Thaleropia of tribe Tristanieae produce the smallest pollen in Myrtaceae, whereas Octamyrtus of tribe Myrteae produces the largest pollen observed in Myrtaceae.

scholarly journals Pollen morphology of the Myrtaceae. Part 2: tribes Backhousieae, Melaleuceae, Metrosidereae, Osbornieae and Syzygieae

2012 ◽  
Vol 60 (3) ◽  
pp. 200 ◽  
Author(s):  
Andrew H. Thornhill ◽  
Geoff S. Hope ◽  
Lyn A. Craven ◽  
Michael D. Crisp
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Size Variation ◽  
Pollen Grains ◽  
Pollen Type ◽  
Diagnostic Characters ◽  
Pollen Types ◽  
Scanning Electron

Pollen morphology of 16 genera and 101 species from the Myrtaceae tribes Backhousieae, Melaleuceae, Metrosidereae, Osbornieae and Syzygieae was surveyed using scanning electron microscopy (SEM) and light microscopy (LM). The most common pollen type observed in these tribes was parasyncolpate with arcuate or angular colpi, and a rugulate exine pattern. There was little size variation in observed pollen, except for larger pollen in tribe Melaleuceae. All Metrosideros pollen grains had apocolpial islands, as well as all Callistemon species viewed by LM. Choricarpia of tribe Backhousieae had pollen with a distinctive exine pattern. Dicolporate pollen were observed in two tribes, Metrosidereae (Tepualia) and Syzygieae (Acmena), and may be of systematic value. The dicolporate grains of these two genera were also easily distinguishable from each other by using size and pollen side shape as diagnostic characters. Two pollen types were observed within the genus Melaleuca, and a number of pollen types were observed within the species-rich genus Syzygium.

scholarly journals Pollen morphology of Iranian Dracocephalum L. (Lamiaceae) and its taxonomic significance

2015 ◽  
Vol 22 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Maryam Naderifar ◽  
Ali Sonboli ◽  
Abbas Gholipour
Keyword(s):  
Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Polar View ◽  
Taxonomic Significance ◽  
Infrageneric Classification ◽  
Exine Ornamentation ◽  
Plant Taxon ◽  
Scanning Electron

Pollen morphology of 11 Iranian Dracocephalum L. species was investigated using light and scanning electron microscopy to evaluate their taxonomic significance for the infrageneric classification of the genus. Pollen grains of all examined taxa were isopolar, hexacolpate, circular in polar view and spheroidal to prolate in equatorial view (P/E = 1.0?2.0). The smallest pollen grains were observed in D. aucheri (P = 29.7 ?m, E = 22.6 ?m), while the largest pollen was found in D. lindbergii (P = 45.1 ?m, E = 33.7 ?m). The highest and lowest apocolpium index (AI) were measured in D. aucheri (AI = 0.27) and D. surmandinum (AI = 0.08), respectively. Colpus membrane was egranulate in all examined species except for D. multicaule and D. ghahremanii. The main exine ornamentation type was characterized as bireticulate including five different subtypes. The results revealed that the exine ornamentation is a diagnostic character useful for the classification of Dracocephalum.Bangladesh J. Plant Taxon. 22(2): 99-110, 2015 (December)

Chrysophycean stomatocysts from the postglacial sediments of a High Arctic lake

1988 ◽  
Vol 66 (6) ◽  
pp. 1117-1128 ◽  
Author(s):  
Katharine E. Duff ◽  
John P. Smol
Keyword(s):  
Species Composition ◽  
Light Microscopy ◽  
High Arctic ◽  
Ellesmere Island ◽  
Arctic Lakes ◽  
Ecological Research ◽  
Stratigraphic Analysis ◽  
Morphological Detail ◽  
Electron And Light Microscopy ◽  
Scanning Electron

Twenty-six chrysophycean stomatocyst morphotypes were described from the postglacial sediments of a small, rock basin lake near Baird Inlet, Ellesmere Island. Scanning electron and light microscopy were used to classify the stomatocysts, following the guidelines of the International Statospore Working Group. None of the stomatocysts could be related with certainty to the chrysophyte species that produced them, but sufficient morphological detail is present in most of the stomatocysts to allow for taxonomic differentiation. A stratigraphic analysis of the dominant stomatocyst morphotypes revealed that chrysophyte species composition changed most markedly during the lake's early development but then remained relatively constant. This study demonstrated that chrysophycean stomatocysts provide useful paleoecological information in High Arctic lakes, but further taxonomic and ecological research is required to fully exploit these microfossils.

Taxonomic implications and evolutionary trends in pollen of Canadian Ericales

1986 ◽  
Vol 64 (12) ◽  
pp. 3113-3126 ◽  
Author(s):  
Barry G. Warner ◽  
C. C. Chinnappa
Keyword(s):  
Pollen Morphology ◽  
Evolutionary Relationships ◽  
Evolutionary Trends ◽  
Fungal Symbiont ◽  
Pollen Types ◽  
Taxonomic Implications ◽  
The Individual ◽  
Individual Grains ◽  
Evolutionary Progression ◽  
Scanning Electron

The pollen of 61 of about 80 taxa of Ericales that occur in Canada are described through the use of light and scanning electron microscopy. Five main pollen types are recognized: (I) compact tetrads in which the individual grains are not clearly delimited when rolled and viewed in all positions, and possessing costae endopori or costae endocolpi, (II) tetrads in which the individual grains are clearly and consistently delimited, occasionally possessing costae endopori or costae endocolpi, (III) a category in which grains within the tetrad are not consistently delimited, and lack costae endopori or costae endocolpi, (IV) loose tetrads in which individual grains are poorly fused, and (V) monads. A key identifies general morphological distinctions among the pollen groups or species. This survey of the pollen morphology of the Ericales supports conventional taxonomic treatments. We favour treatment of Monotropaceae and Pyrolaceae as separate families and suggest the elevation of Orthila secunda to its own monotypic family. The Clethraceae and Orthila secunda may be better treated outside the Ericales. We propose that the tetrad pollen of most Ericales is a derived condition from the more primitive trizonocolporate monad of the Cyrillaceae, Clethraceae, and Orthila secunda. Subfamily Vaccinioideae (Ericaceae) and Empetraceae, through subfamily Rhododendroideae (Ericaceae), to Pyrola and Moneses (Pyrolaceae), and finally to Chimaphila (Pyrolaceae) represent the evolutionary progression based on a trend from compact tetrads to loose individual grains within the tetrad. Finally the most advanced group is represented by the zonoaperturate monads of the Monotropaceae. This evolutionary progression based on pollen morphology is in accord with general principles of tetrad formation during microsporogenesis and with evolutionary relationships suggested by the macromorphology, phytochemistry, embryology, and degree of dependence on a fungal symbiont.

scholarly journals Pollen morphology of the Balkan-Carpathian endemic Campanula lingulata Waldst. & Kit. (Campanulaceae)

2016 ◽  
pp. 75-82
Author(s):  
Marina Macukanovic-Jocic ◽  
Snezana Jaric
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Endemic Species ◽  
Pollen Morphology ◽  
Average Length ◽  
Pollen Grains ◽  
Polar Axis ◽  
First Time ◽  
Scanning Electron

Palynomorphological characteristics of Campanula lingulata, the Balkan-Carpathian endemic species growing in Serbia, have been investigated using light microscopy and scanning electron microscopy for the first time, in order to provide some information helpful for a better understanding of the taxonomic position of this species within the genus, as well as to contribute to the pollen atlas of Serbian apiflora. The pollen grains are radially symmetrical, isopolar, 3-zonoporate and medium-sized monads oblate-sphaeroidal in shape. Mean of the polar axis (P) is 27.6?1.9 ?m, while the average length of the equatorial axis (E) is 28.8?1.6 ?m. The apertures are operculate. The sculpturing pattern of the exine is microre?ticulate-microechinatae. The exine surface is covered with evenly distributed supratectal spinules of variable length and sparse granules. The longest supratectal spinules are 0.64?0.05 ?m in length and the smallest sculptural elements are less than 0.2 ?m high. The microechinae density per sample area of 5 ?m x 5 ?m averages 17.4?2.4.

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