scholarly journals Taxonomic value of the leaf blade epidermal structure at the sectional level of Altai fescue (Festuca L.)

Author(s):  
E. A. Kriuchkova ◽  
M. V. Olonova ◽  
E. Z. Baiakhmetov ◽  
P. D. Gudkova

Here we present results of our study on the leaf blades epidermis using scanning electron microscopy for 16species of Festuca from Altai. The factor analysis of mixed data revealed markedly differentiated groups according to theirsectional devision. This result supports the previous phylogenetic findings in the genus, except the section Aulaxyper. Thestudy also demonstrates the importance of the abaxial side of leaves in taxonomic treatment of the species, specifically theshape of long cells and silicon bodies, as well as the location of the latter.

1995 ◽  
Vol 73 (12) ◽  
pp. 1947-1952 ◽  
Author(s):  
Raul Dodsworth Machado ◽  
Cláudia Franca Barros

The outer epidermal cell walls of the leaf blade of the licuri palm tree were studied by light microscopy, scanning electron microscopy, and transmission electron microscopy, with special attention to the epicuticular waxes. On the intensely green adaxial surface, the wax adheres in the form of a smooth, flexible, varnish-like layer. On the pruinose, dull, greenish or bluish abaxial side, the wax appears as a thin amorphous layer from which rodlets and columns protrude. Very curved rodlets, in compact rows, border each stoma, sometimes almost completely closing its aperture. Numerous pores, not resolvable with the light microscope, were detected in both cuticular membranes. Comments are presented concerning the possible functions of several configurations of epicuticular waxes. Key words: epicuticular waxes, wax micromorphology, Syagrus, licuri, epidermal wall.


1993 ◽  
Vol 71 (9) ◽  
pp. 1202-1211 ◽  
Author(s):  
M. Colson ◽  
R. Pupier ◽  
A. Perrin

The enumeration of peltate glands on Mentha ×piperata leaves was carried out with respect to the date of leaf initiation and the state of its development. For this purpose, observations were made using scanning electron microscopy associated with a mathematical method based on a precise description of gland dispersal on the leaf blade surface. The number of glands can thus be estimated by using only a few photographs of the foliar region located at 2/5 of the leaf length, measuring from the base. The analyses demonstrate a consistency in the number of peltate glands for a given foliar verticil, when the leaf height is equal to or greater than 10 mm. Furthermore, these analyses indicate that the number of peltate glands vary as a function of the level of the foliar verticil. This number increases progressively in verticils 1 to 10, stabilizes, and then decreases in the last verticils produced. This reduction may originate in the meristematic activity that is gradually oriented towards efflorescence. Key words: Mentha, glandular trichomes, enumeration, spatial distribution, leaves, scanning electron microscopy. [Journal translation]


Kew Bulletin ◽  
2019 ◽  
Vol 74 (4) ◽  
Author(s):  
Salwa Shahimi ◽  
Maria Conejero ◽  
Christina J. Prychid ◽  
Paula J. Rudall ◽  
Julie A. Hawkins ◽  
...  

SummaryThe rattan genus Korthalsia Blume (Arecaceae: Calamoideae: Calameae) is widespread in the Malesian region. Among the 28 accepted species are 10 species that form intimate associations with ants. The ants inhabit the conspicuous ocreas that are produced by these species, using them as domatia to care for their young and aphids. As a foundation for future work, we present here a taxonomic treatment of the myrmecophilous Korthalsia species, based on extensive research pursued both in the herbarium and the field. In addition, we conduct detailed morphological characterisation of the structure and development of ocrea using light and scanning electron microscopy. Descriptions, illustrations, keys and distribution maps are presented for all 10 species, along with microscopic images of ocrea morphology and development for selected species.


2020 ◽  
Vol 193 (4) ◽  
pp. 504-522
Author(s):  
Alex Batista Moreira Rios ◽  
Gisele Cristina de Oliveira Menino ◽  
Valdnéa Casagrande Dalvi

Abstract Leaf teeth are projections on the leaf blade margin. They are structurally variable, with characters that are important for taxonomy and phylogeny, but there is a paucity of information on the anatomy of these structures and little understanding of the features and their functions. Here we describe and compare the leaf tooth anatomy of 47 eudicot species. Toothed margin samples from leaves at different developmental stages were collected, fixed and studied under light and scanning electron microscopy. We identified eight leaf tooth morphotypes, six of which occurred with glands. Hydathodes were the most common glands, being found in 11 species; colleters were found in ten species and extrafloral nectaries were found in two species. Cunonioid teeth either devoid of glands or associated with hydathodes were found in Lamiales, Asterales and Apiales. Dillenioid teeth associated with hydathodes were found in Dilleniales. Spinose teeth associated with colleters were found in Aquifoliales. In rosids, we found begonioid, malvoid, theoid, urticoid and violoid teeth, which may be associated with either colleters or nectaries or lack an associated gland. For each family studied, there was only one type of association between gland and tooth, demonstrating the systematic potential of these glands in eudicots.


2004 ◽  
Vol 52 (3) ◽  
pp. 285 ◽  
Author(s):  
G. Prenner

The floral development of Daviesia cordata Smith is studied by the use of scanning electron microscopy. This is the first study of a member of Mirbelieae. Although organ initiation in Papilionoideae is said to be almost uniformly unidirectional from the abaxial to the adaxial side, the presented floral development shows striking differences from this mode. Sepals, petals and the antepetalous stamens are initiated in simultaneous whorls, which is seen as a consequence of harmonisation of the plastochrons within the whorls. The antesepalous stamens are initiated unidirectional from the adaxial to the abaxial side, which is the reversed direction of the common mode of Papilionoideae. This is the first record of reversed unidirectionality in Papilionoideae, which can be linked with isolated findings in Caesalpinioideae and Mimosoideae. Concerning developmental aspects, the results seem to link the papilionoid flower closer to those of Caesalpinioideae and Mimosoideae. Further developmental studies are necessary to broaden the data matrix for a detailed phylogenetic analysis.


1978 ◽  
Vol 56 (16) ◽  
pp. 1982-1991 ◽  
Author(s):  
Judith G. Croxdale

A study of floating and submerged Salvinia leaves using light and scanning electron microscopy shows unique features in the arrangement of leaves and their growth. Leaves are produced in phyllotactic units of six; within each phyllotactic unit are two sets or groups of three leaves each. The genetic spiral of leaf initiation is not unidirectional but alternates from clockwise to counterclockwise with the production of each group of three leaves. Within each group of leaves, the sequence of primordial expansion is the reverse of their inception. Observations of floating leaf apical cells show that during development they undergo configurational changes from rectangular to hemisperical to lenticular to tetrahedral. Floating and submerged leaves diverge structurally when they are 70–90μm in length. The general course of leaf development appears to differ from previously described ferns and angiosperms in that each floating leaf blade panel is generated from the abaxial primordial surface.


2012 ◽  
Vol 64 (1) ◽  
pp. 27-34
Author(s):  
Mirosława Chwil ◽  
Elżbieta Weryszko-Chmielewska

The investigations were carried out using light and scanning electron microscopy. The flowers of <i>Elaeagnus commutata</i> grow in clusters of 1-4 in the leaf axils. They are actinomorphic, four-lobed, with a single perianth that is yellow from the adaxial side, while the abaxial side is silvery-white. Peltate hairs of different structure are found on both surfaces of the sepals. The conical epidermal cells of the lobes are covered with a thick striated cuticle. Cylindrical hairs were observed on the edges of the lobes. Peltate hairs also grew on the style. The dish-shaped nectary gland is located at the base of the style. Nectar is secreted through numerous, evenly distributed stomata located above or at the level of other epidermal cells. Different stages of stomatal development are evidence of the asynchronous functioning of the stomata. The nectary consists of small epidermal cells and 5-6 layers of secretory parenchyma. The deeper layers of the gland are composed of larger cells of subglandular parenchyma in which vascular bundles supplying the nectary run. Honey bees were the main pollinators of silverberry. Ten silverberry flowers produced an average of 12 g of nectar with a sugar concentration in the 29.5-34.5% range. The weight of pollen produced by 10 flowers was 3.33 mg.


2009 ◽  
Vol 57 (1) ◽  
pp. 65 ◽  
Author(s):  
Maria Cecília de Chiara Moço ◽  
Jorge Ernesto de Araujo Mariath

Floral organogenesis of six Brazilian species of Adesmia DC. was studied by scanning electron microscopy. Considering the number of species, this is the most comprehensive organogenetic study of a genus conducted. A unidirectional sepal formation from the adaxial towards the abaxial side of the floral meristem is shown for the first time in the subfamily Papilionoideae. This pattern was found in all studied taxa except for A. latifolia in which the five sepal primordia are formed simultaneously. The present study suggests that the ontogenetic floral differences among Adesmia species may be useful in a re-evaluation of infrageneric categories and for future systematic analyses.


Phytotaxa ◽  
2015 ◽  
Vol 226 (3) ◽  
pp. 217 ◽  
Author(s):  
Victor Martins Gonçalez ◽  
Gerleni Lopes Esteves

Melochia occurs in the Southeast Region of Brazil, comprising ten species and two varieties, which corresponds to about 50% of the Brazilian species. The genus is mainly distributed in the Cerrado. This study provides a taxonomic treatment including an identification key, illustrations, comments on morphology, habitat, geographical data and conservation status. Some species cited for the region, but not found in the present research are referenced with additional notes. Also, a new status (Melochia regnellii), a lectotypification, five new records for the Southeast Region, and a Scanning Electron Microscopy study (unpublished for the genus) are here presented.


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