Contributions to the pollen morphology and taxonomy of the Liliaceae

Pollen of 34 species from 7 genera of the Liliaceae were examined by LM and SEM with respect to the taxonomy of the family. Detailed pollen­morphological characteristics are given for all genera in the family on the basis of the results presented here together with data from the literature. The genera Tulipa and Lilium are heterogeneous in both aperture type and exine ornamentation. Pollen of Tulipa is monosulcate, 3-aperturate or inaperturate, with a microreticulate-striate, reticulate-implecto-striate, scabrate, perforate-rugulate, perforate-striate exine surface. Pollen of Lilium is monosulcate and 3-porate with a macroreticulate exine. The other genera are homogeneous in possessing of single longitudinal aperture (type monosulcate). The pattern of exine ornamentation and the structure of the aperture and its membrane are peculiar features for species and genera. Pollen of Erythronium and Tulipa are occasionally operculate, while in other representatives of the Liliaceae an operculum is lacking. Pollen morphological data support the division of the family into 3 tribes, namely Lloydieae, Lilieae, and Tulipeae.     

Can Triticum urartu (Poaceae) be identified by pollen analysis? Implications for detecting the ancestor of the extinct two‐grained einkorn‐like wheat

The domestication of the one‐grained einkorn (Triticum monococcum) in the Near East is relatively well known. However, an independent two‐grained einkorn‐like domestication has been archaeobotanically detected and scarce information is available. Triticum urartu, a wild wheat, was not fully described until the 1970s because the phenology does not allow it to be distinguished easily from wild einkorn (Triticum boeoticum subsp. thaoudar), although a genetic separation exists. Both species are mostly two grained and could potentially be the relatives of the extinct two‐grained form. Pollen grains of several genetically well‐identified wheat species, including T. urartu and T. boeoticum subsp. thaoudar, were studied by measuring the grain diameter and examining the exine sculpturing with phase‐contrast microscopy and scanning electron microscopy to gain an insight into differences enabling taxonomic identification. This work showed that, although T. urartu pollen is smaller on average, grain diameter is not sufficient because of the size overlap between the species, but T. urartu presents a different exine sculpturing (scabrate) from other Triticum spp. (aerolate). This outcome is useful for taxonomists and archaeobotanists. First, it will allow a simple re‐classification of herbarium materials. Second, further research could establish whether T. urartu was cultivated. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 278–289.     

Pollen morphology of Brazilian Fevillea (Cucurbitaceae)

Pollen morphology of the five Brazilian species of the genus Fevillea (F. bahiensis, F. cordifolia, F. passiflora, F. pedatifolia, and F. trilobata) was studied using light and scanning electron microscopy. Pollen in these species is generally stenopalynous, which is in agreement with observations in previous studies of other species. Pollen is shed in monads and characterised by being isopolar, radially symmetric, prolate, and striate. Pollen is of medium size, tricolporate, with long and narrow colpi, a circular endoaperture and a reduced polar area. The exine is up to 2 μm thick.     

Some evidence for infrageneric classification in Ziziphora L. (Lamiaceae:Mentheae)

The genus Ziziphora L. (Lamiaceae) consists of annual herbs, except Ziziphora clinopodioides, and is represented by six taxa in the flora of Turkey: Z. clinopodioides, Z. capitata, Z. persica, Z. tenuior, Z. taurica subsp. taurica and Z. taurica subsp. cleonioides. They are strong aromatic herbs and important medicinal plants. This study has been conducted to determine the palynological and karyological features of these taxa. The pollen morphology and exine structure of Ziziphora species were investigated by light microscope and scanning electron microscope. Pollen grains were determined as hexacolpate, medium in size and a circular or elliptic amb. The shape of pollen grains varies from oblate to prolate spheroidal. Ornamentation types of pollen grains are bireticulate, microreticulate or perforate. Somatic chromosome number has been determined and counted as 2n = 16, 18. Results indicate that the pollen characters and chromosome numbers of the genus are valuable for taxonomic applications and may be useful for infrageneric classification.     

A New Pollen Type in the Winteraceae

Pollen of Zygogynum balansae and Z. pomiferum is described with the aid of the scanning electron microscope. Other members of the primitive ranalean family Winteraceae hitherto investigated have pollen in permanent tetrads, but these two species have solitary grains. Sculpturing is similar on the distal and proximal faces of each grain, excluding the distal apertural zone. The exine pattern resembles that on distal faces of tetrads of other Zygogynum species investigated, including Z. bailloni, the pollen of which is illustrated. Although Zygogynum and Exospermum have rather similar pollen, with sculpturing differing from other Winteraceae in consisting of a less coarse reticulum, pollen of Exospermum stipitatum is clearly distinct from the Zygogynum species investigated, as seen in the scanning electron microscope. It is not clear whether or not the solitary pollen type has evolved from the tetrad form.     

Pollen morphology and its relation with meiotic irregularities in ten species of Campuloclinium (Eupatorieae,Asteraceae)

Pollen grains of ten species of Campuloclinium (Eupatorieae, Asteraceae) are described and illustrated using light and scanning electron microscopy. The species included in this study are C. burchelli, C. campuloclinioides, C. chlorolepis, C. hirsutum, C. irwinii, C. macrocephalum, C. megacephalum, C. parvulum, C. purpurascens and C. riedelli. Pollen grains of Campuloclinium are typically radially symmetric, echinate, tectate, oblate-spheroidal to prolate-spheroidal (P/E ratio: 0.94–1.10). Pollen is mostly triaperturate, but tetraaperturate or biaperturate pollen also occurs in some species. The pollen diameter was highly variable ranging from 10.54 µm to 36.18 μm. The significance of the variation in type and size of pollen is discussed in relation to diverse meiotic abnormalities and possible reproductive apomictic processes within the polyploid species.     

Pollen morphology of the genus Euphrasia L. (Orobanchaceae) from Pakistan and Kashmir and its taxonomic significance

Pollen morphology of 25 species of the genus Euphrasia L., belonging to the family Orobanchaceae from Pakistan has been examined by light and scanning electron microscope. It is a stenopalynous genus. Pollen grains are usually radially symmetrical, isopolar, tricolpate, sub-prolate to prolate-spheroidal rarely oblate-spheroidal. Sexine slightly thinner than nexine or as thick as nexine. Tectum coarse to fine retipilate or rugulate–retipilate. On the basis of exine ornamentation three distinct pollen types viz., Euphrasia foliosa, Euphrasia multiflora, and Euphrasia incisa are recognized. Pollen morphology is significantly helpful at specific level within the pollen type.     

Species distinction in the “Potentilla pollen type” (Rosaceae) of NW Europe

Pollen grains of eight different species from the genera Comarum, Fragaria, Potentilla and Sibbaldia, usually considered as one type, the “Potentilla type”, were examined and morphological features making distinction possible are described     

Pollen morphology of the Dimorphandra group (Leguminosae,Caesalpinioideae)

The Dimorphandra group, as traditionally circumscribed, is a rather diverse assemblage of genera in Leguminosae subfamily Caesalpinioideae that share certain morphological characteristics with the basally branching lineages of subfamily Mimosoideae. It currently comprises 51 species in seven genera: Burkea (1 species), Dimorphandra (26 species), Erythrophleum (10 species), Mora (6 species), Pachyelasma (1 species), Stachyothyrsus (2 species) and Sympetalandra (5 species). This study investigates the pollen morphology of 25 samples from 19 species of all seven genera. Pollen of the Dimorphandra group is small, isopolar, trizonocolporate and released in monads. Apertures are almost equal to polar length, with correspondingly small apocolpial areas. The shape of the aperture apices varies from acute to wide and rounded. Surface ornamentation is psilate, perforate, microreticulate, or perforate‐rugulate. The wall structure is usually columellate with a well developed foot layer. The pollen is small and unspecialised, agreeing with a previously noted pattern of more fixed and homogenous pollen structure in the more derived clades in subfamily Caesalpinioideae, compared with the great diversity of pollen types found in the basally branching lineages.     

Pollen morphology in Asiatic species ofTrillium

Pollen grains of five species and two interspecific hybrids ofTrillium from eastern Asia have been examined with scanning electron and transmission electron microscopy. All species from eastern Asia, excludingT. govanianum, are characterized by inaperturate pollen and an unstratified and granulated exine structure. Pollen of the Himalayan species,T. govanianum, is, however, monocolpate and intectate. The palynological evidence suggests that the Asiatic species, excludingT. govanianum, are closely related to each other and toT. erectum in North America, andT. govanianum is independent of the other species in the genus.     

POLLEN MORPHOLOGY OF THE CHLORAEINAE (ORCHIDACEAE: DIURIDEAE) AND RELATED SUBTRIBES

Pollen organization and morphology of the South American Chloraeinae (Orchidaceae) was examined by scanning electron microscopy and compared with that of the remainder of the otherwise Australasian Diurideae. All five genera of the Chloraeinae, Bipinnula, Chloraea, Codonorchis, Gavilea, and Geoblasta, and at least one genus from each of the other subtribes were sampled. The Australasian Diurideae are diverse in pollen organization and morphology. The two genera of the Acianthinae, Corybas and Acianthus, have very different pollen and their classification is questioned. Monad pollen organization of Pterostylis (Pterostylidinae) is reinterpreted as primitive and not secondarily derived. Pollen of the Chloraeinae is uniform in exine morphology and organization. Most species sampled have reticulate pollen which tends to be foveolate distally. The basic pollen unit of all Chloraeinae is the tetrad, except Codonorchis which possesses monads. Pollen morphology and organization of the Chloraeinae is most similar to the Caladeniinae, which supports the contention that the Chloraeinae including Codonorchis should be retained in the Diurideae.     

Ultrastructural Study of Cytoplasmic Inclusions in Plants Infected with Potyviruses

The ultrastructure of cell inclusions of different ornamental plants infected with several filamentous viruses of the potyviruses was studied at the transmission electron microscope. The plants examined were: Crocus sativus, Hyacinthus sp., Gladiolus sp., rhizomatous Iris, Muscari sp., Nerine bowdenii and Sparaxis sp. Differences in morphology of cylindrical inclusions have been used to separte the potyviruses in several subdivisions.     

Studies on pollen morphology of selected species of Annonaceae from Thailand

The pollen morphology of 49 species and one variety, representing 18 genera of the family Annonaceae from Thailand, is described and illustrated based on observations using scanning electron microscopy (SEM). The pollen grains of Anaxagorea show double-spheres as a result of the intine extrusion. The palynological evidence confirms the close relationship of Dasymaschalon, Desmos and Asian Friesodielsia. Decussate tetrads in Goniothalamus and coexisting tetragonal, rhomboidal, T-shaped, tetrahedral and decussate tetrads in Mitrephora are reported. Pollen morphology is consistent within Huberantha, Marsypopetalum and Monoon, but is more diverse in Polyalthia sensu stricto Pollen unit, shape, size, ornamentation and aperture number reaffirm the great diversity among and within genera in Annonaceae.     

POLLEN MORPHOLOGY OF THE EUCHARIDEAE (AMARYLLIDACEAE)

Eucharis, Caliphruria, and Urceolina form a monophyletic group of petiolate-leaved, Neotropical Amaryllidaceae ecologically specialized to the understory of primary tropical rain forest below 2,000 m elevation. Pollen morphology of the three genera is surveyed. Pollen grains of all species of Eucharis, Caliphruria, and Urceolina are boat-shaped elliptic, monosulcate, heteropolar, and bilateral in symmetry. Exine sculpturing is semitectate-columellate and reticulate in all species examined. A transformation series in reticulum coarseness and pollen grain size is described. The large pollen grain with coarse reticulum of most Eucharis species is considered ancestral. The fine reticulation of Caliphruria is considered derived and the exine morphology of Urceolina is intermediate. Both of these genera have medium-sized pollen grains. Exine dimorphism common to all Urceolina, but rare in Eucharis and Caliphruria, may be symplesiomorphous among those taxa exhibiting this morphology. The three genera are largely uniform in pollen grain ultrastructure, with completely ektexinous exines. Pollen grain size in Eucharis is not closely correlated with style length. Several wide-ranging species show considerable intraspecific variation in pollen size. Parallelisms in pollen grain evolution among related tribes of Neotropical Amaryllidaceae are discussed.     

POLLEN MORPHOLOGY IN THE GENUS ERYTHRONIUM (LILIACEAE) AND ITS SYSTEMATIC IMPLICATIONS

Pollen morphology was examined in 40 samples from 19 species in the genus Erythronium (Liliaceae) using scanning (SEM) and transmission electron microscopy (TEM). Pollen grains are monosulcate monads, except for a plant of E. oregonum which has dyad grains. North American and European species are characterized by reticulate exine sculpture composed of various degrees of wavy muri and variably-sized lumina. The most distinctive feature of exine sculpture in the genus is exhibited by the Asian species E. japonicum, which has a unique reticulate pattern composed of striate muri and a distinctive exine structure without columellae. The distinctness of E. japonicum pollen suggests that it has specialized in isolation from species in North America and Europe.     

Canrightiopsis,a new Early Cretaceous fossil with Clavatipollenites-type pollen bridge the gap between extinct Canrightia and extant Chloranthaceae

Canrightiopsis with three species (C. intermedia, C. crassitesta, C. dinisii) is described from the Early Cretaceous of Portugal based on small, one-seeded berries. The fruits are derived from bisexual flowers with three stamens borne on one side of the ovary. There are no traces of a perianth. Pollen is of the Clavatipollenites-type, monocolpate, semitectate, reticulate-columellate with heterobrochate reticulum and muri with beaded supratectal ornamentation. The ovary is unilocular with a single pendant, orthotropous and bitegmic ovule. The seed is endotestal. The endotesta consists of one layer of palisade-shaped crystal cells with fibrous infillings. The fruit wall has resin bodies or cavities from presumed ethereal oil cells sometimes seen as stomata-like structures on the fruit surface. A phylogenetic analysis resolves Canrightiopsis as a close relative of extant Chloranthaceae, particularly close to extant Chloranthus and Sarcandra. All three taxa share the one-sided position of the stamens on the ovary. An evolutionary sequence from fossil Canrightia to fossil Canrightiopsis and extant Chloranthus and Sarcandra is suggested by loss of perianth, reduction in number of ovules and stamens and displacement of stamens to one side of the ovary. Canrightiopsis also shares several critical features with extant Ascarina including monoaperturate pollen and beaded supratectal ornamentation of the pollen wall.     

Chrysophyceae from freshwater localities near Nijmegen,The Netherlands

Scale-bearing Chrysophytes from nine freshwater bodies in the surroundings of Nijmegen, The Netherlands, have been studied using both scanning and transmission electron microscope.A comparison has been made with a previous study in the northern part of The Netherlands by Wujek & van der Veer (1976).This paper deals with three species of Mallomonopsis, twenty-one species and one variety of Mallomonas, four species and three formae of Synura, one species of Chrysosphaerella, two species of Spiniferomonas and three species and one form of Paraphysomonas. One species of Mallomonopsis, twelve species of Mallomonas, one form of Synura, Chrysosphaerella brevispina and one species and one form of Paraphysomonas are for the first time recorded from The Netherlands. One species of Mallomonopsis and one species of Spiniferomonas could not be identified.Some physical and chemical data of the sampling localities are given.     

Pollen morphology and systematics of Atripliceae (Chenopodiaceae)

Pollen morphology of 58 species from 17 putative genera of the tribe Atripliceae (Chenopodiaceae) was investigated using light (LM) and scanning electron microscopy (SEM). Morphological variation was analyzed based on a dense sampling of the subtribes Atriplicinae and Eurotiinae, including many of the species in the two largest genera: Atriplex and Obione. The pantoporate pollen grains of Atripliceae are characterized by their spheroidal or subspheroidal shape, flat or moderately vaulted mesoporia with 21–120 pores, tectum with 1–8 spinules and 5–28(?38) puncta per?µm², and 1–13 ectexinous bodies bearing 1–7 spinules each. Taxonomic relevance of the most important pollen morphological characters is discussed (pollen diameter, pore number, pore diameter, interporal distance, spinule and puncta density and ratio, number of ectexinous bodies, and their spinules). Pollen morphological data support the exclusion of Suckleya from the tribe and the recognition of subtribe Eurotiinae, but suggest that it needs to be reviewed. Pollen does not support generic recognition of Atriplex, Neopreissia and Obione and infrageneric subdivisions as currently recognized, and suggests the need to review them. Smaller or monotypic genera, such as Axyris, Ceratocarpus, Endolepis, Krascheninnikovia, Microgynoecium, Proatriplex and Spinacia have distinctive pollen morphological characters that support their generic status. Grayia needs to be reevaluated; although its two species are distinct from all the other species in the study, there are notable differences between each of them, and this suggests they may not form a natural group. Multivariate techniques were employed to investigate if there are discrete patterns of variation within Atripliceae. Principal Component Analyses (PCA) weakly differentiates four groups based on variation in pore number, puncta density per?µm², and ratio between spinule and puncta density per?µm²; species of Ceratocarpus, Haloxanthium, Krascheninnikovia, Manochlamys, Microgynoecium, Spinacia, and some species of Atriplex and Obione are isolated. Preliminary results indicate that pollen data are potentially useful in the classification of the tribe, and further studies will be of taxonomic value.     

Palynological analysis of Brazilian geopropolis sediments

The sediments of 10 samples of geopropolis collected from 3 species of Meliponinae in the states of Espírito Santo, Minas Gerais and São Paulo, Brazil, and obtained after chemical treatment, were analysed. Pollen grains, hyphae and spores of fungi, organic material and burned plant fragments were observed in the majority of samples. Sandy or earth materials was present in all geopropolis sediments. Pollen analysis identified the dominant, accessory and isolated plant taxa occurring in the areas of geopropolis sample recovery. The most important pollen types found were Eucalyptus (Myrtaceae) in samples from the state of São Paulo only, Schinus (Anacardiaceae) mainly in samples from the state of Minas Gerais and Myrcia (Myrtaceae) in every state. Two samples were devoid of pollen grains. Only one sample contained plant trichomes and was considered a propolis sample of Apis bees. Compared to propolis samples examined previously, the geopropolis pollen spectra reflect the characteristic regional vegetation and also a higher variability of plant species visited by the Meliponinae. It is established that geopropolis samples can be distinguished from propolis samples by light microscope analysis of sediments. Mineral and soil constituents, as well as the lack of trichomes, are characteristic only of geopropolis.     

Lessingianthus (Vernonieae–Asteraceae): generic and infrageneric relationships based on pollen morphology

Pollen morphology of 31 species of Lessingianthus was investigated in order to evaluate the generic and infrageneric relationships of Lessingianthus and related genera. Acetolyzed pollen grains were measured, described and illustrated using light microscopy. Non‐acetolyzed pollen grains were investigated using scanning electron microscopy. Pollen grains of Lessingianthus are isopolar monads, suboblate, oblate spheroidal or prolate spheroidal, lophate (30, 29 and 27 lacunae), with small or large polar area, tricolporate. Pollen grains with 30 lacunae occur in the majority of the species examined, and show three apertural, six abapertural, twelve parapertural, six interapertural and three equatorial lacunae. Pollen grains with 29 lacunae occur in L. desertorum, L. simplex and L. virgulatus and are characterized by three apertural, six abapertural, twelve parapertural, six interapertural and two polar lacunae, and by absence of equatorial lacunae. Pollen grains with 27 lacunae occur in L. adenophyllus and L. durus and are characterized by three apertural, six abapertural, twelve parapertural and six interapertural lacunae, but lack polar and equatorial lacunae. Species of Lessingianthus subgen. Lessingianthus, with few exceptions, have pollen grains with type B lophate pattern, which differs mostly in shape. Pollen grains of Lessingianthus subgenus Oligocephalus share a very similar pattern of 29 lacunae with those of Chrysolaena, supporting recently proposed taxonomic changes. Pollen grains with 27 regular lacunae occur in Lessingianthus durus and L. adenophyllus, but the first differ from the latter by having cross muri enclosing the apertural lacuna (type G pollen).