Results 211 to 220 of about 23,420 (258)

Evolution of Pollen Morphology

Science, 1991
Over evolutionary time, the morphology of angiosperm pollen has evolved toward an increasing number of apertures, among other things. From a neo-Darwinian point of view, this means that (i) some polymorphism for aperture number must exist and (ii) there must be some fitness increase associated with increasing the aperture number.
I, Dajoz, I, Till-Bottraud, P H, Gouyon
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Pollen morphology in the trimeniaceae

Grana, 1984
Abstract Piptocalyx macrurus Gilg & Schlechter, P. moorei Oliver and Trimenia neocaledonica Baker f. have disulculate, globose-elliptic or globose-spherical to globose-elliptic grains, with finely reticulate or rugulose (T. neocaledonica) structure. T. papuana Ridley has dimorphic pollen, with only one type on an individual plant, consisting of either ...
F. B. Sampson, P. K. Endress
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Pollen morphology ofLactoridaceae

Plant Systematics and Evolution, 1986
The pollen wall ultrastructure of the primitive AngiospermLactoris fernandezianaPhil. (Lactoridaceae) is described. The monosulcate aperture, granular wall structure and sacci (all primitive features) suggest placement of this family in theMagnoliales.
Michael S. Zavada, Thomas N. Taylor
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Pollen Morphology as an Index to Plant Relationship. I. Morphology of Pollen

Botanical Gazette, 1925
The paper reports a study of pollen morphology in numerous genera of about eighty families represented in the flora of Colorado, together with a small number of familiar exotic forms. A discussion is given of the general interest of pollen, with methods of study and preservation. Pollen shapes are described, as well as markings, size, color, stickiness,
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Trends in pollen morphology: 6th bibliographic index to pollen morphology of angiosperms

Grana, 1991
Abstract The sixth volume in the series of bibliographic indices to the pollen morphology of the angiosperms initiated by G. Thanikaimoni in 1972 is analysed with respect to the three main instruments used for the description of the pollen grains, viz, light microscopy, scanning electron microscopy and transmission electron microscopy.
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The Pollen Morphology of Moringaceae

Kew Bulletin, 1985
The pollen morphology of 13 species of the genus Moringa has been studied. The pollen exine is rather distinctive and uniform in structure throughout the family. It is spheroidal, tricolporate with costate colpi, the ornamentation is psilate with sparse puncta, the endexine is very thick at the apertures but almost absent from the mesocolpial and polar
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Pollen morphology of the Onagraceae

Review of Palaeobotany and Palynology, 1967
Abstract This incomplete but comprehensive survey based upon the pollen of 21 genera and over 100 species of the Onagraceae shows the following pollen types: 1. ( 1 ) Pollen in tetrads and disarticulated tetrads. The single grains usually have a thicker ring at the base of the somewhat aspidote pore. This condition occurs in Epilobium (in part),
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Pollen morphology of Ulmaceae

Grana, 1983
Abstract Thirty-two species from 17 genera were examined by scanning electron microscopy and representatives from each subfamily were examined by transmission electron microscopy. The treatment of Ulmaceae based on pollen grains is consistent with the treatment of the family presented by I. A. Grudzinskaya.
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Comparative pollen morphology and ultrastructure of the Callitrichaceae

American Journal of Botany, 2000
The Callitrichaceae are an aquatic family of dicots that include the single, geographically cosmopolitan genus Callitriche. Callitriche contains 40–50 terrestrial, amphibious, and obligately submersed species, and it is the only known genus in the plant kingdom with co‐occurring aerial and hydrophilous pollination syndromes.
R L, Cooper, J M, Osborn, C T, Philbrick
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3. POLLEN MORPHOLOGY

TAXON, 1980
SummaryPollen morphology ofAralidiumshows no close resemblance to that of the Araliaceae, Cornaceae (sens, lat.), or Griseliniaceae.
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