The epidermis in Passerina/ (Thymelaeaceae): structure, function and taxonomic significance

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.

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.


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


2012 ◽  
Vol 19 (1) ◽  
pp. 25-31 ◽  
Author(s):  
C.S. Ogundare ◽  
S.A. Saheed

Studies on the leaf epidermal characters and petiole anatomy of four species of Citrus L. viz., C. limon (L.) Burm., C. paradisi Macf., C. reticulata Blanco and C. sinensis (L.) Osbeck were carried out to establish and document their foliar anatomical characters with the aim of separating them from the modified varieties been cultivated globally. Leaf epidermal features that revealed close relationship among these taxa include hypostomatic condition, stomata shape and type, presence of secretory cavity on the adaxial surface, and polygonal shape of epidermal cells. The absence of secretory cavity on the abaxial surface separates C. limon and C. sinensis from others. Petiole anatomy revealed that the outline is flat without ribs in C. sinensis, convex with short ribs in C. reticulata, convex with long ribs in C. paradisi while in C. limon it is circular without ribs. Presence of trichomes and crystals distinguishes C. paradisi from the rest.DOI: http://dx.doi.org/10.3329/bjpt.v19i1.10938Bangladesh J. Plant Taxon. 19(1): 25-31, 2012 (June)


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.


2020 ◽  
Vol 23 ◽  
pp. 63-68
Author(s):  
M.B. Olaniyi ◽  
I.O. Lawal ◽  
M.I. Adeniyi

The leaves of Crescentia cujete Linn belonging to Bignoniaceae family have been reported to exhibit some important medicinal properties such as antioxidant, antimicrobial, anti-tumour and anti-inflammatory activities. This study therefore evaluated the chemoscopic, macro-morphological andmicromorphological attributes of powdered, fresh and anatomical sections of Crescentia cujete Linn leaves using standard methods. The result ofchemoscopic study confirmed presence of calcium oxalate crystals, fat deposits and traces of lignin in numbers on epidermal surfaces. Macro-morphological study revealed that C. cujete leaves are deep green in colour with faint odour, sour taste and smooth-feel with non-granular  surfaces. Micromorphological examinations indicated that epidermal cells are irregular, rectangular to polygonal in shape on the abaxial surface but epidermal cells on the adaxial surface were straight, slightly undulating with thick anticlinal cell walls. Paracytic stomata arrangement was found only on the abaxial surfaces. Quantitative leaf microscopy confirmed that epidermal cells had average sizes of 37.52 ± 4.62 – 39.23 ± 4.73 μm in  length while cell width was 25.51± 0.86 – 27.76 ± 4.21μm. The stomata length was 15.66 ± 2.04 and 6.29 ±0.93 in width. Organoleptic and other  parameters evaluated on C. cujete shows that it has optimum potential for herbal drug development and a baseline for species identification.


Phytotaxa ◽  
2017 ◽  
Vol 299 (1) ◽  
pp. 36
Author(s):  
MOJGANSADAT MOHTASHAMIAN ◽  
FARIDEH ATTAR ◽  
KAVEH KAVOUSI ◽  
ALI MASOUDI-NEJAD

As the largest genus of broad leaved deciduous trees, Acer L. contains about 126 species distributed in the temperate regions of the Northern Hemisphere. With eight native species in Iran, maples are among the most important tree species in the country. Micromorphological traits of 39 populations of Iranian native species indicated the value of leaf epidermal characteristics in identification and classification of maples. A number of epidermal morphological features of the abaxial surface were investigated using LM and SEM images. The occurrence of stomata in clusters is reported for the first time in Acer. The shape of the epidermal cells, anticlinal cell wall patterns, type of indumentum, and epicuticular waxes were the most significant variables in this study. The ability of quantitative and qualitative variables in segregating the studied taxa was evaluated by statistical methods, including PCA, MCA and Non-parametric analyses.


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.


1990 ◽  
Vol 68 (3) ◽  
pp. 630-639 ◽  
Author(s):  
Marcia J. Waterway

The structures of the achene epidermal cells and their included silica deposits are illustrated and described for 28 species that have been referred to Carex section Hymenochlaenae. On the basis of these epidermal features, there are anomalous species in nearly all of the subsections and sections that have been circumscribed by Kükenthal, Mackenzie, Ohwi, and Koyama. Furthermore, some species with nearly indistinguishable achene surface features have quite different overall morphologies and have traditionally been placed in different sections. Similarities in the structure of the silica deposits in the achene epidermal cells may result from the retention of the primitive character state in several different lineages or from parallel development of modified silica bodies or wall structures in different lineages. Levels of homoplasy appear to be too high to make these characters reliable indicators of evolutionary relationships in Carex section Hymenochlaenae.


1978 ◽  
Vol 56 (17) ◽  
pp. 2097-2108 ◽  
Author(s):  
Verna J. Higgins ◽  
G. L. Lazarovits

As part of a continuing study of non-host resistance, red clover leaves inoculated with the clover pathogen Stemphylium sarcinaeforme, or the closely related alfalfa pathogen S. botryosum, were examined by light and electron microscopy to compare the events occurring in the initial stages of infection. Stemphylium botryosum penetrated leaves primarily via the stomata with resultant death of the guard cells and with varying effects on adjacent epidermal cells. Appressoria were frequently formed, and although they rarely resulted in successful penetrations, the contacted epidermal cells were often markedly affected as judged by toluidine blue staining. Growth of hyphae was intercellular but very limited in its extent. At some infection sites, one to several mesophyll cells underwent extensive plasmolysis and cytoplasmic disruption. Less severely affected mesophyll cells contained large lipid bodies, abundant rough endoplasmic reticulum, and Golgi vesicles and had wall appositions at points of contact with necrotic cells or with hyphae. Stemphylium sarcinaeforme generally penetrated between or directly through the epidermal cells, causing death of the contacted cells. Hyphae grew intercellularly or intracellularly in the palisade tissue and hyphal elongation was considerably more rapid than that of S. botryosum. Palisade cells adjacent to, or containing, the hyphae underwent several different types of cytoplasmic deterioration. Mesophyll cells surrounding these areas showed the same features as comparable cells in tissue infected by S. botryosum. In tissue infected by either fungus, the exterior of host cell walls was coated with a layer of extracellular material.


2014 ◽  
Vol 38 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Diego Ismael Rocha ◽  
Luzimar Campos da Silva ◽  
Eduardo Gusmão Pereira ◽  
Bruno Francisco Sant'Anna-Santos ◽  
Elisa Rodrigues Gontijo ◽  
...  

This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.


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