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Journal ArticleDOI

Anatomy of the Dicotyledons.

About: This article is published in American Midland Naturalist.The article was published on 1950-11-01. It has received 2511 citations till now.
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Journal ArticleDOI
21 Feb 2010-Biologia
TL;DR: The anatomical features of the root, the stem, the leaf and the petiole, as well as micromorphological characteristics of the pollen and the nutlet of this species have been investigated using Scanning Electron Microscopy (SEM).
Abstract: Salvia macrochlamys Boiss. & Kotschy, which belongs to sect. Salvia Hedge, is a perennial herb usually growing on rocky limestone slopes in eastern Anatolia. In this study, the anatomical features of the root, the stem, the leaf and the petiole, as well as micromorphological characteristics of the pollen and the nutlet of this species have been investigated using Scanning Electron Microscopy (SEM). Moreover, its emended and expanded description, phenology, current distribution and ecology are also given. Anatomical characters such as the number of ray lines in the root, the distance between vascular bundles in the stem, the structure of mesophyll in the leaf and the structure of vascular bundles in the petiole have been found to have taxonomic value. The pollen grains are hexacolpate, radially symmetrical, isopolar and oblate-spheroidal. Their exine sculpturing is bireticulate and perforate. The nutlets are rounded-trigonous in transverse sections, broadly ovate to rotund in shape, light brown, glabrous and slightly rough to protuberances. This species often grows in habitats in which the main soil type is sandy-clayish with low organic content (1.32 ± 1.06%) and slightly alkaline (pH 7.75 ± 0.25). The amount of CaCO3 is 0.94% to 34.91%. The contents of P and K are 8.68 ± 0.96 and 110.12 ± 4.86 ppm, respectively.

30 citations

Journal ArticleDOI
TL;DR: Micromorphological features of the leaf-blade, lemma, and palea were examined under scanning electron microscopy for 64 species of the genus Festuca L. occurring in the Iberian Peninsula to assess their taxonomic value and compare the variation with recent DNA sequence-based phylogenies.
Abstract: Micromorphological features of the leaf-blade, lemma, and palea were examined under scanning electron microscopy (SEM) for 64 species of the genus Festuca L. occurring in the Iberian Peninsula. The objective of the study was to survey these characters for the first time in the whole of the genus Festuca in this region, to assess their taxonomic value, and to compare the variation with recent DNA sequence-based phylogenies. The principal features include the frequency, shape, and distribution of silica bodies, short cells, crown cells, and prickles, and the morphology of long cells. The abaxial lemma surface shows the most important taxonomical and phylogenetic characters. The variation observed was consistent with the subgenera and sections identified in molecular studies.

30 citations

Journal ArticleDOI
31 Aug 2007-Flora
TL;DR: The observation of ant visits at these structures reinforces the assumption that EFNs mediate ant–plant interactions and play a protective role against herbivores throughout the life of a leaf.

30 citations

Journal Article
01 Jan 2007-Caldasia
TL;DR: A morphological study of 38 species of Baccharis used in traditional medicine was carried out to provide some epidermal characters that will contribute to the knowledge of the genus.
Abstract: A morphological study of 38 species of Baccharis used in traditional medicine was carried out to provide some epidermal characters that will contribute to the knowledge of the genus. The present study revealed: 1) seven different types of trichomes: conical, aseptate fl agellate, fi liform fl agellate, 1-armed, 2-4-armed, bulbiferous fl agellate, and glandular biseriate; 2) that 28 of the total of 38 species have trichomes in tufts; 3) six different types of stomata: anomocytic, anisocytic, cyclocytic, actinocytic, tetracytic, and staurocytic; 4) that some trichome types, such as 2-4-armed (B. dracunculifolia) and aseptate fl agellate branched (B. trinervis), show a high diagnostic value; 5) that the stomata types can be used to differentiate species with similar trichomes type (e.g. B. trimera and B. articulata). Illustrations of the studied characters are provided.

30 citations

Journal ArticleDOI
TL;DR: It is indicated that the genera GigantopterisGigantonoclea form the basis of the gigantopterid concept and current evidence suggests that Gigantpteris nicotianaefolia is restricted to the southern floral regions of Cathaysia, as typically are other species of this genus.
Abstract: Reinvestigation of the first described gigantopterid plant, Gigantopteris (Megalopteris) nicotianaefolia Schenk ex Potonie, 1902 from the Permian of China, has been conducted using the original specimens documented in 1883. The application of new techniques has permitted a comprehensive review of their morphology. This study represents the first photographic record of Schenk's specimens and provides a standardised terminology to describe them. This species of Palaeozoic leaf megaphyll is characterised by its pinnate venation, with tertiary veins that anastomose, and give rise to branches that may be of the same or higher order. These anastomosed branches form a reticulum of irregular polygonal meshes, within which higher order veins anastomose and again form meshes. On examination of Schenk's original specimens only one, MB.Pb.2002/989, can be assigned to Gigantopteris nicotianaefolia, and this is herein designated the lectotype. The remaining specimens described by Schenk are reassigned to cf. G. nicotianaefolia, cf. Gigantopteris sp., Gigantonoclea sp. or cf. Gigantonoclea sp. This re-analysis of Schenk's specimens has led to an emended diagnosis of both the genus Gigantopteris and the species G. nicotianaefolia. Current evidence suggests that Gigantopteris nicotianaefolia is restricted to the southern floral regions of Cathaysia, as typically are other species of this genus. Fertile specimens of Gigantopteris are unknown, and the status of these plants as a natural group relies upon a combination of their complex foliar physiognomy, stratigraphic range, and geographical distribution. This study indicates that the genera GigantopterisGigantonoclea form the basis of the gigantopterid concept. These two genera share characters of leaf morphology including megaphylls with eucamptodromous venation across which extends a continuous lamina, and higher order veins, third order or above, that arise from the secondary veins and anastomose to form complex meshes. These genera are distinguished in that the venation of Gigantopteris is far more complex than that of Gigantonoclea, with a greater number and complexity of vein orders, the penultimate and ultimate of which form meshes within meshes, and of these the finest may terminate in blind endings.

30 citations