scholarly journals Micromorphology of endemic Centaurea glaberrima subsp. divergens (Asteraceae)

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

Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 806-814 ◽  
Author(s):  
Kiriaki Nurit-Silva ◽  
Rafael Costa-Silva ◽  
Ionaldo J.L.D. Basílio ◽  
Maria de Fátima Agra

To evaluate their taxonomic significance, the yet unknown epidermal characters of the leaves of 10 species of Solanum section Torva Nees (Solanaceae) from Brazil were determined using light and scanning electron microscopy. Our results indicated that the leaf epidermis showed epidermal cells of straight to wavy outlines. The curved pattern of anticlinal cell walls was predominant on the adaxial surface, and the wave pattern was predominant on the abaxial surface. Leaves are amphistomatic in six species ( Solanum acutilobum Dunal, Solanum bonariense L., Solanum guaraniticum A. St.-Hil., Solanum metrobotryon Dunal, Solanum scuticum M. Nee, and Solanum torvum Sw.) and hypostomatic in four species ( Solanum adspersum Witasek, Solanum paniculatum L., Solanum subumbellatum Vell., and Solanum variabile Mart.). Four different types of stomata (anisocytic, anomocytic, paracytic, and diacytic) were recognized, with the anisocytic type predominant on adaxial and abaxial surfaces. The combination of some micro-morphological characters such as density, distribution and type of stellate trichomes, the anticlinal walls of epidermal cells, and also the type and distribution of stomata proved to be the most useful and distinctive characters for the separation of species. This set of characters also may help as additional support in quality control of species having medicinal importance.


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.


2004 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Do R. DUARTE ◽  
J. F. LOPES

Galinsoga parviflora Cav. e G. ciliata (Raf.) Blake são herbáceas medicinais, empregadas popularmente no tratamento de ulcerações cutâneas e distúrbios hepáticos. Este trabalho teve por objetivo caracterizar a epiderme foliar dessas espécies, por meio de análise fotônica e ultra-estrutural. Folhas adultas foram fixadas e submetidas a técnicas usuais de microscopia fotônica e de varredura. Ambas as espécies apresentam epiderme foliar uniestratificada e revestida por cutícula delgada e levemente estriada. Em vista frontal, as células epidérmicas revelam contorno sinuoso e estômatos anomocíticos ocorrem em ambas as superfícies. Tricomas tectores pluricelulares e unisseriados predominam na face adaxial. Esse anexo epidérmico é comparativamente mais numeroso em G. ciliata. OPTICAL AND ULTRASTRUCTURAL ANALYSIS OF THE LEAF EPIDERMIS OF Galinsoga parviflora CAV. AND G. ciliata (RAF.) BLAKE, ASTERACEAE Abstract Galinsoga parviflora Cav. and G. ciliata (Raf.) Blake are medicinal herbs, popularly employed for treating cutaneous ulcers and hepatic insufficiency. This work has aimed to characterize the leaf epidermis of these species, by means of optical and ultrastructural analysis. Mature leaves were fixed and undergone usual optical and scanning microtechniques. Both species have got uniseriate leaf epidermis, coated by thin and slightly striated cuticle. In face view, the epidermal cells show sinuous contour and anomocytic stomata are seen on both surfaces. Pluricellular and uniseriate non-glandular trichomes predominate on the upper side. This epidermal appendage is comparatively more frequent in G. ciliata.


2012 ◽  
Vol 62 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Mirosława Chwil ◽  
Elżbieta Weryszko-Chmielewska

The present study involved the measurement of size and the micromorphology of the floral elements of <i>Anchusa officinalis</i> L. which are attractants for insects. The structure of the epidermis on the surface of the calyx, petals, throat scales, pistil and nectary were analysed using light and scanning electron microscopy (SEM). For light microscopy observations, semi-permanent slides were prepared, which were treated with Lugol's iodine solution, Sudan III and fluoroglucine. The dark violet lobes of the corolla of <i>Anchusa officinalis</i>, with a velvety surface, and the throat scales, contrasting with them, belong to the most important optical attractants which lure insects from large distances. The dark pink colouring of the sepals additionally increases the attractiveness of the flowers. The epidermis covering the calyx formed different-sized non-glandular trichomes as well as glandular trichomes. The glandular trichomes were composed of a uni - or bicellular leg and a unicellular head. The colour of the corolla petals was determined by anthocyanins accumulated in the epidermal cells and in the more deeply situated parenchyma. The velvety surface was formed by the conical papillae, densely growing from the adaxial epidermis. The pink-violet throat scales with white hairs, covering the inlet to the tube of the corolla, were found at the inlet to the corolla throat. The longest trichomes on the surface of the scales were located in their lower and middle parts, whereas the shortest ones at their tips. The epidermis of the central part of the throat scales formed small papillae. The trichomes had thin cell walls, large vacuoles, numerous plastids and lipid droplets. The two-parted stigma of the pistil was covered by characteristic expanded outgrowths with wavy edges which performed the functions of structures facilitating the capture of pollen grains. As a result of the present study it was found that the structures affecting the attractiveness of the flowers, through various light effects within the corolla of <i>Anchusa officinalis</i>, include the papillae on the corolla surface, trichomes of the throat scales and the epidermal cells of the style. The trichomes of the scales can also be responsible for protecting pollen and nectar against rainfall.


Bothalia ◽  
2000 ◽  
Vol 30 (1) ◽  
pp. 69-86 ◽  
Author(s):  
C. L. Bredenkamp ◽  
A. E. Van Wyk

Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.


Phytotaxa ◽  
2019 ◽  
Vol 391 (3) ◽  
pp. 167 ◽  
Author(s):  
MIN-JUNG KONG ◽  
SUK-PYO HONG

A comparative study of the leaf microstructures of 19 taxa belonging to the Persicaria sect. Cephalophilon and related four Koenigia taxa was performed by LM and SEM to evaluate their systematic significance. Both amphistomatic and hypostomatic leaves were observed in the taxa studied. The stomatal size ranged from 17.04–41.96 × 13.41–37.30 μm, and stomata on the adaxial side were larger than those on the abaxial side in general. Anomocytic stomata occurred most commonly, but more than one type of stomata was observed on the same surface. Paracytic stomata was found in both Persicaria palmata and P. criopolitana. The epidermal cells usually have straight to sinuate anticlinal cell walls (ACW), and the ACW on the abaxial side of most taxa is much more undulated than that on the adaxial side. Cuticular striation was observed in most of the studied taxa, which was restricted to only the adaxial side. Two types of crystals were observed: druse and prismatic, and seven types of trichome were recognized: five types of non-glandular trichomes (stellate with smooth surface, multiseriate with either smooth or striated surface, and uniseriate with either smooth or papillose surface), and two types of glandular trichomes (peltate and long-stalked pilate). The leaf micromorphology in this study was categorized into five types based on the stomata, epidermis, crystal and trichome, as further systematic significance of the leaf epidermal characters within the P. sect. Cephalophilon are discussed. In addition, we propose a new taxonomic combination in the P. sect. Cephalophilon.


2001 ◽  
Vol 14 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew C. Rozefelds ◽  
Richard W. Barnes ◽  
Belinda Pellow

The vegetative and reproductive morphology of Vesselowskya Pampanini, southern marara, is described and illustrated in detail. The variation within V. rubifolia (F.Muell.) Pampanini sens. lat. is shown to be greater than has previously been recognised, with the differences identified supporting the recognition of a new segregate species, V. venusta Rozefelds, R.W.Barnes and Pellow sp. nov. Vesselowskya venusta occurs in the Barrington Tops Plateau of New South Wales and differs from V. rubifolia in possessing hairs on the abaxial surface of the sepals and lacking both a prominent distal connective protrusion on the anthers and colleters at the base of the stipules. The two Vesselowskya species are dioecious with a vestigial ovary in staminate flowers and reduced stamens in pistillate flowers. Dioecy is more pronounced in Vesselowskya, than in some Weinmannia species, and in both genera is expressed through reduction in the size of the ovaries in staminate flowers, and stamens in pistillate flowers. Vesselowskya shares with the other genera in the tribe Cunonieae (Pancheria, Weinmannia and Cunonia), a central column in the fruits, and Cunonia-type stipules, but differs from these genera in having valvate aestivation, digitate leaves, craspedodromous secondary venation with secondary veins terminating at a tooth, tuft domatia along the midrib, adaxial epidermal cells with strongly sinuous cell walls and the absence of hydathodes.


2014 ◽  
Vol 62 (8) ◽  
pp. 647 ◽  
Author(s):  
Ana Paula Lorenzen Voytena ◽  
Bruno Degaspari Minardi ◽  
José Bonomi Barufi ◽  
Marisa Santos ◽  
Áurea Maria Randi

While many ferns have been described as desiccation tolerant (DT), few studies have reported on the mechanisms they use to survive cell desiccation. Among the species belonging to the genus Pleopeltis, P. pleopeltifolia (Raddi) Alston (Polypodiopsida, Polypodiaceae) is a DT species endemic to Brazil. So as to better characterise the mechanisms of desiccation tolerance in ferns, the present study aimed to analyse frond anatomy and physiological changes associated with desiccation and rehydration of P. pleopeltifolia. Fronds are dorsiventral, with uniseriate epidermis. The epidermal cells have various shapes, tending to stretch in the longitudinal direction of the frond. Anticlinal cell walls are sinuous, and periclinal cell walls are convex. Anomocytic stomata are restricted to the abaxial surface. Trichome-type scales are found on both sides of the frond and may play a relevant role in rehydration of this plant when water is available. The mesophyll of the frond consists of palisade parenchyma, tending to a bistratified adaxial surface and spongy parenchyma on abaxial surface. The cuticle on the adaxial surface is conspicuous, ensuring better control of internal water balance. For physiological analyses, sporophytes were subjected to desiccation for 0, 5, 10 and 15 days and rehydration for 1 day. Sporophytes showed a sharp decline in water content when kept without irrigation, reaching 9.6% after 15 days, in addition to wilting and frond rolling. A significant increase in sugar content in fronds was noticeable during desiccation, which may favour a possible osmotic adjustment and vitrification. A notable increase in proline content during rehydration was observed in fronds. During the five initial days of desiccation, the chlorophyll and carotenoid contents decreased abruptly, but after 1 day of rehydration, they had partly recovered. The photosynthetic parameters analysed by fluorescence of chlorophyll a ceased completely after 15 days of desiccation but they had recovered near to pre-desiccation levels after 1 day of rehydration.


2012 ◽  
Vol 64 (4) ◽  
pp. 35-46 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil

In the climatic conditions of Lublin, <i>Crocus vernus</i> blooms from the third decade of March until the third decade of April. The flowers live for 3-4 days. Micromorphological investigations of the tepals and perianth tube as well as of the stamens and pistil were carried out using scanning electron microscopy. The anatomical features of the perianth segments and flower stem were examined with the use of light and fluorescence microscopy. Pollen grains were observed under a light microscope. It was found that the adaxial and abaxial epidermal cells formed papillae in the middle and lower part of the tepals. Much smaller papillae are formed in the upper region of the perianth tube. Elongated non-glandular and glandular trichomes, with spherical protrusions at the tip, are found at the base of the filaments. The filaments are distinguished by epidermal cells with a longitudinally striated cuticle and by the presence of papillae of varying number and size. The cylindrical papillae on the stigma of the pistil are covered by a wrinkled cuticle. The style is surrounded by the perianth tube along a significant length. A narrow space is formed between these organs, and it is filled by the nectar. Stylar channels are found in the style. We observed calcium oxalate crystals and numerous plastids in the parenchymal cells surrounding these channels. Inaperturate, spherical pollen grains are covered by numerous tryphine (or pollenkitt) droplets. This paper also discusses the functions of the papillae found in the epidermis of the perianth and filaments.


2012 ◽  
Vol 61 (2) ◽  
pp. 25-34 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil

The micromorphology of selected elements of <i>Echium vulgare</i> L. flowers was investigated, with special attention to the structure of the nectaries and the stigma of the pistil as well as types of trichomes occurring on the surface of the calyx. The nectary had the shape of an uneven disc located around the lower region of the four-parted ovary of the pistil. The glandular cells formed a tier with a height of 330 μm and a radial width of 144 μm. Nectar was secreted onto the nectary surface through anomocytic stomata located at the level of other epidermal cells. Most of the stomata were open, with a different dimension of the pore. Their largest number was observed at the base of the nectary, and 462 stomata were noted on the whole surface of the nectary. The cuticle on the surface of the guard cells formed fine, circular striae. The subsidiary cells formed striated cuticular ornamentation, with the striae arranged radially in the direction of the stoma, whereas on the surface of other epidermal cells the striae formed an arrangement with different directions. The epidermis on the surface of the stigma formed regularly arranged papillae with a fan-shaped, expanded upper part which had corrugated outer walls, whereas the base of the cell formed a widened small column. The epidermis of the abaxial part of the calyx was covered by numerous non-glandular trichomes of different length which were made up of one or several cells. The glandular trichomes in the epidermis of the calyx grew with smaller density compared to the protective trichomes, and they were composed of a 1-2-celled stalk and a glandular head.


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