scholarly journals A preliminary leaf epidermal and pollen morphology of some West African species of Desplatsia Bocq

Author(s):  
Emmanuel O. Shokefun ◽  
Abiodun E. Ayodele ◽  
Emuobosa A. Orijemie

Desplatsia is a genus made up of about four to eight species which are mostly trees native to tropical Africa. The leaf and pollen characters of three West African species of Desplatsia were investigated using light microscopy. The study was aimed at investigating the leaf epidermis and pollen morphology of the species to further enhance the understanding of the taxonomic relationships in the genus. The epidermal cells were isodiametric, polygonal to irregular with straight, curved to wavy anticlinal cell walls. The species were hypostomatic with anisocytic and staurocytic stomata types. The adaxial and abaxial walls of Desplatsia chrysochlamywere characterised by three-celled head multicellular glandular trichomes with highest number of cells and stomata and striated adaxial surface. The four-armed branched and stellate trichomes with the largest stomata size of 19.5 µm × 15.6 µm distinguished D. dewevrei from D. subericarpa in which the largest cells, lowest number of stomata and size were recorded. The pollen grains were medium in size 26.5 µm–47.5 µm, tricolporate with long colpi. However, the subprolate, baculate exine surface, small ora and lumen width separated D. chrysochlamy from D. dewevrei and D. subericarpa in which prolate, perforated exine surface and colpi margo were recorded. A key is provided for the identification of the species. Therefore, the ora size, lumen width, number of epidermal cell and stomata are additional taxonomic characters that can be used for species delimitation in the genus.

2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Milan Gavrilović ◽  
Pedja Janaćković

In this study, the micromorphology of the vegetative and reproductive structures of the endemic Centaurea glaberrima Tausch subsp. divergens (Vis.) Hayek (Asteraceae), using scanning electron microscope (SEM), is presented for the first time. Uniseriate whip-like non-glandular and biseriate glandular trichomes are found on the surface of all aboveground parts (stem, leaves, peduncles, involucral bract). On the adaxial leaf epidermis ribbed thickenings (striation pattern) of outer periclinal cell walls, slightly curved anticlinal cell walls and anomocytic stomata are noticed. Rugose abaxial surface with thorny protuberances of the involucral bract is documented. Corolla is glabrous with longitudinally parallel epidermal cells with distinct straight outline. Isopolar, radially symmetric and tricolporate microechinate pollen grains are seen. Short stylar hairs, without cuticular striations, are present along the outer sides of the style, while the inner sides (abaxial surface) constitute the papillate stigmatic surface. Microcharacters found in cypsela are as follows: slightly ribbed body; rotund base; lateral and concave insertion; short, unicellular curly acute trichomes; smooth epidermis; fine-sulcate ornamentation; rod shaped epidermal cells with short, obtuse end walls and straight anticlinal walls; poorly developed minutely dentate pericarp rim; and dimorphic pappus with bristles of different length and morphology, with pinnules restricted to the margins of the bristles. The results obtained contribute to knowledge about the micromorphology of the studied endemic species and provide features for its better identification. The taxonomic significance of the analyzed characters is discussed. Some well defined microcharacters of the studied species might have taxonomic value


2017 ◽  
Vol 24 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Ebadi-Nahari Mostafa ◽  
Nikzat-Siahkolaee Sedigheh ◽  
Eftekharian Rosa

Pollen morphology of nine species representing four genera: Cephalaria Schrad, Dipsacus L., Pterocephalus Vaill. and Scabiosa L. of the family Dipsacaceae in Iran has been investigated by means of scanning electron microscopy (SEM). The results showed that pollen grains were triporate and tricolpate. The pollen type of Scabiosa rotata Bieb. (tri- and tetraporate) is the first report in the world. The sizes of pollen grains fall into the classification group magna (pollen grain diameter 50–100 μm). Pollen shapes vary from preoblate to prolate and their polar views were triangulate and lobate. The exine ornamentation varies from gemmate in S. rotata to spinulate in the rest studied species. Species of Scabiosa have been dispersed in UPGMA tree that this confirmed the previous studies about taxonomic problems and species complexity in this genus. These results show the transfer of the some Scabisoa species to Lomelosia Raf. based on palynological characters. Pollen morphology of the family is helpful at the generic and specific level.Bangladesh J. Plant Taxon. 24(2): 129–136, 2017 (December)


Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 849-856 ◽  
Author(s):  
M. L. Frean

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.


1956 ◽  
Vol 4 (1) ◽  
pp. 13 ◽  
Author(s):  
KM Pike

The pollen grains of 300 species of 71 genera of the family Myrtaceae have been examined and their characteristic features summarized in tabular form. The investigation has been mainly concerned with those species that occur in the south-west, Pacific area, particularly Australia. For comparative purposes, the pollen morphology of a limited number of South American and two South African species has been included. The significance of pollen characters for distinguishing genera and species within the family is discussed. In some instances pollen morphology has provided additional evidence for the classification of certain species as suggested by taxonomists. A provisional key to pollen grains of the genera examined has been included.


2019 ◽  
Vol 26 (2) ◽  
pp. 131-148
Author(s):  
Burcu Yilmaz Çitak ◽  
Hüseyin Dural ◽  
Tuna Uysal ◽  
Nur Münevver Pinar

In this paper, the palynomorphology of 17 taxa of section Cheirolepis in Turkey, were investigated by light (LM) and scanning electron microscope (SEM). Detailed descriptions of the pollen grains were given for each taxon and a well-resolved dendrogram was generated through numerical analysis of palynological diagnostic features. The pollen grains were found to be radially symmetric, isopolar, and generally 3-zonocolporate, with the exception of C. derderiifolia, C. kotschyi var. floccosa, and C. saligna, which were also 4-zonocolporate. The shape of the pollen grains were prolatespheroidal, with the polar axes of 32.76–46.26 μm and equatorial axes of 31.86–45.82 μm. The sculpturing of the pollen grains was generally scabrate-perforate or rarely microechinate-perforate. The spines were conical with a changing base length. The length and the width of the spines varied between 0.48 and 2.28 μm and 0.4 and 3.39 μm, respectively. The number of perforations at the base of the spines ranged in two or morerows and they varied between 5 and 30. The number of spines was 16–70 in 10 μm2. The results of this study showed that the polar axes, equatorial axes, aperture type, pollen shape, spine length, perforation number, and number of spines in 10 μm2 are essential for distinguishing the studied taxa. The taxa were grouped by clustering analysis of selected pollen characters using the UPGMA method.


2019 ◽  
Vol 42 (3) ◽  
pp. 209-211
Author(s):  
Saurabh Sachan ◽  
◽  
S.B. Padal ◽  

Genus Cassytha (Lauraceae) is characterized by unigue Pollen morphology. We Prepared strains of C. filiformis following acetolysis method (Ikuse, 1956) for observation under Light Microscope and Scanning Electron Microscope. The present study revealed that the lamellar and scbrate nature of exine are entirely different and attributing to different morphology of pollen grains, especially the shape. This communication provides a comparison of pollen morphology between Indian and South African species filiformis discriminates the morphological variations found among the Indian specimens of C. filiformis from that of South African region.


2000 ◽  
Vol 78 (2) ◽  
pp. 208-220
Author(s):  
Charles L Argue

The pollen of all six species of Lyperia (Scrophulariaceae, tribe Manuleae) was investigated by light microscopy and scanning electron microscopy of whole and fractured grains. Pollen grains in Lyperia antirrhinoides (L.f.) Hilliard, Lyperia formosa Hilliard, Lyperia tenuiflora Benth., and Lyperia violacea (Jarosz) Benth. differed from those in Lyperia tristis (L.f.) Benth. and Lyperia lychnidea (L.) Druce in number and length of colpi, sculpturing of the colpus margin, reduction of apocolpial lumina size, reduction of exine thickness toward the colpi, ornamentation of the outer nexine surface, arrangement of columellae beneath the muri, direction of cross-sectional compression in elliptical muri, and relative dimensions of the muri and columellae. Pollen grains from 50 representative species of the putatively related genera Sutera and Jamesbrittenia were also examined. Correlations among quantitative pollen characters of tribe Manuleae and the Sutera complex were investigated by principal components analysis. Morphological similarities in the pollen of Lyperia, genera of the Sutera complex, and other Manuleae were summarized by ordination of the principal components data and (or) cluster analysis. The pollen grains of L. lychnidea and L. tristis differed from those of other Lyperia and stood apart from those of Jamesbrittenia, Sutera, and all other Manuleae. Pollen morphology in Sutera and Jamesbrittenia intergrades with that in tricolporate species of Lyperia.Key words: pollen morphology, Scrophulariaceae, Lyperia, Jamesbrittenia, Sutera.


Phytotaxa ◽  
2020 ◽  
Vol 428 (3) ◽  
pp. 228-240
Author(s):  
HÜLYA ÖZLER ◽  
AHMET KAHRAMAN ◽  
SEVİL PEHLİVAN ◽  
MUSA DOĞAN ◽  
BİROL BAŞER ◽  
...  

The pollen grains of 19 Turkish Salvia species in Aethiopis, Drymosphace, Hemisphace, Hymenosphace and Salvia sections, 13 of which are endemic to Turkey, were investigated, documented and illustrated through Light Microscopy (LM) and Scanning Electron Microscopy (SEM). This study provides pollen data of 14 species for the first time. The pollen grains of the species examined are monads, isopolar, radially symmetrical and hexacolpate, mostly medium in size, slightly elliptic to more or less circular in polar view and mainly oblate-spheroidal in equatorial view. Two different ornamentation types are recognized on exine sculpturing; reticulate-perforate and bireticulate. The present results do not generally support the traditional infrageneric classification of Salvia, but provide useful pollen characters for species delimitation.


2012 ◽  
Vol 81 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Parisa Panahi ◽  
Mohammad R. Pourmajidian ◽  
Asghar Fallah ◽  
Mehdi Pourhashemi

For the first time, pollen morphology of 9 (4 spp. and 5 subspp.) taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for <em>Quercus</em> section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within <em>Quercus</em> section in Iran.


PhytoKeys ◽  
2019 ◽  
Vol 128 ◽  
pp. 121-140 ◽  
Author(s):  
Catalina Ruiz-Domínguez ◽  
Andrew P. Vovides ◽  
Victoria Sosa

Hylocereeae is one of the nine tribes in the subfamily Cactoideae (Cactaceae), for which the limits and recognition of genera have been controversial. Essentially, this group comprises epiphytic and hemiepiphytic genera with stems modified as climbing structures. The aim of this paper is to examine pollen attributes in representative species of genera of Hylocereeae, focusing on Selenicereus whose current circumscription comprises Hylocereus and three Weberocereus species, to find whether significant potentially apomorphic and/or autapomorphic systematic characters can be discovered. Utilizing SEM and light microscopy, 25 pollen characters were observed and measured. Tribe Hylocereeae is stenopalynous, with pollen grains isopolar and radially symmetrical monads, mostly tricolpate, except in Kimnachia, Pseudoripsalis and Weberocereus, whose pollen grains are pantocolpate. Seven attributes (five qualitative and two continuous) exhibited useful variation and were coded. The character of brevicolpate pollen grains was shared by Kimnachia ramulosa and Pseudorhipsalis amazonica. Convex quadrangular outline in the polar view was shared by Weberocereus tunilla and S. glaber. The absence of spinules on the exine was shared by S. minutiflorus and S. stenopterus. The largest pollen grain, found in Selenicereus megalanthus, might be correlated with polyploidy. Selenicereus is the taxon with the highest variation in pollen attributes, including species with an exine with or without spinules and variable polar area index and shape (subprolate or oblate-spheroidal).


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