Clausospicula, a new Australian genus of grasses (Poaceae, Andropogoneae)

1991 ◽  
Vol 4 (2) ◽  
pp. 391
Author(s):  
M Lazarides ◽  
J Lenz ◽  
L Watson
Keyword(s):  
Cell Walls ◽  
Transverse Section ◽  
Northern Territory ◽  
Vascular Bundles ◽  
Monotypic Genus ◽  
Prominent Feature ◽  
Abaxial Epidermis ◽  
Diagnostic Characters ◽  
Adaxial Epidermis

Clausospicula, a new monotypic genus from the Darwin and Gulf District, Northern Territory, Australia, is described and illustrated. Its diagnostic characters include cleistogamous spikelets, reduced panicles, racemes and spikelets, and pedicelled spikelets which are poorly developed and deciduous, or suppressed. Also, the glumes of the bisexual spikelet are awned and slightly keeled or without keels. A prominent feature is the extension of the peduncle into an appendage to which the callus of the bisexual spikelet is attached. The epidermis is notable for its distinct costal and intercostal zones, rectangular intercostal long-cells with tessellated, pitted cell walls, stomata inserted beneath the overlapping interstomatals and arranged in definite rows bordering the costal zones, the presence of macrohairs, narrow microhairs 39–46.5 µm long, silica-celllcork-cell pairs with dumbbell-shaped silica bodies costally and butterfly-shaped silica bodies intercostally. The transverse section shows a distinct midrib with the vascular bundles arranged in a conventional arc abaxially and colourless tissue adaxially, and a symmetrically ordered lamina. The primary vascular bundles are accompanied by sclerenchyma as girders abaxially and adaxially; the adaxial epidermis is extensively bulliform and the abaxial epidermis is of bulliform-like cells.

scholarly journals Comparative Foliar Epidermal Studies in Coix lacryma-jobi L. andCoix aquatica Roxb. (Poaceae)

2009 ◽  
Vol 1 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Rinku Jitendrakumar DESAI ◽  
Vinay Madhukar RAOLE ◽  
Arun Omprakash ARYA
Keyword(s):  
Light Microscopy ◽  
Species Identification ◽  
Foliar Analysis ◽  
Abaxial Epidermis ◽  
Diagnostic Characters ◽  
Pointed Apex ◽  
Adaxial Epidermis ◽  
The Cross ◽  
Micromorphological Characters ◽  
Diagnostic Importance

As micromorphological knowledge was not available for Coix aquatica Roxb., the foliar epidermal studies were carried out for Coix lacryma-jobi L. and Coix aquatica Roxb. with the aim of determining the patterns of variation in their epidermal characteristics and assessing their value in species identification. Comparative foliar analysis was carried out by using light microscopy, after following routine scraping method. The characters of diagnostic importance in the identification of C. aquatica are the sparsely distributed prickle hairs with long pointed apex in the abaxial epidermis and dumbbell shaped silica cells in both the epidermises. The diagnostic characters for C. lacryma-jobi are the cross shaped silica cells and dumbbell shaped on the abaxial and adaxial epidermis respectively. The observed differences in certain micromorphological characters helps in identification of presently studied two species of Coix.

Morphology and epidermal characters of Ginkgo pilifera Samyl. leaves and distribution of this species in the Late Cretaceous of Northern Asia

Palaeobotany ◽  
2016 ◽  
Vol 7 ◽  
pp. 5-37
Author(s):  
L. B. Golovneva
Keyword(s):  
River Basin ◽  
Cell Walls ◽  
Western Siberia ◽  
Leaf Shape ◽  
Northeastern Russia ◽  
Abaxial Epidermis ◽  
Adaxial Epidermis ◽  
Subsidiary Cells ◽  
Periclinal Walls ◽  
Kolyma River

In the result of investigation of new findings, the variability of leaf shape and epidermal characters of Ginkgo pilifera Samyl. were studied. Geographical and stratigraphic ranges of this species were analyzed on the base of new material and earlier published data. This species was described by Samylina (1967) from the upper part of the Timmerdyakh Formation exposed in the Lena-Vilyui depression in Eastern Siberia. After that many new occurrences of this species were reported. G. pilifera was widely distributed from late Albian to Maastrichtian in Asian part of the Siberian-Canadian paleogeographical region. The earliest occurrence was documented from the late Albian-lower Turonian deposits of the Krivorechenskaya Formation, Grebenka River basin, Northeastern Russia. Approximately in the same time (in the Cenomanian) remains of G. pilifera appeared in the lower part of the Timmerdyakh Formation in the Lena-Vilyui depression. In Western Siberia in the late Albian and Cenomanian other species of Ginkgo were found: G. sertensis N. Nosova et Golovn. and G. chlonoviae N. Nosova et Golovn. were described from the Kiya Formation and G. ragosinii N. Nosova et Golovn. and G. tjukansis Kiritch. were described from the Simonovo Formation. In the Turonian and Coniacian G. pilifera was discovered in the upper part of the Timmerdyakh Formation, in the Valizhgen Formation of Yelistratov peninsula in Penzhina Bay area, in volcanogenic deposits of the Kolyma River basin and in the Derevyannye Gory Formation of New Siberia Island. In the Santonian-Campanian this species was reported from the Arkagala Formation of the Kolyma River basin and from two localities in the Amur River basin: from upper part of the Kundur Formation in Russia and from the Taipinglinchang Formation in China. The last occurrence is the most southern finding of this species. In Maastrichtian G. pilifera penetrated in Western Siberia, that significantly increased its area in western direction. The most variable character in G. pilifera morphology is the leaf shape. Leaves change from entire to deep-dissected into several wide lobes with rounded or truncate apices. Dissected forms occured from late Albian to Coniacian and predominated in the Krivorechenskaya (late Albian-lower Turonian) and the Valizhgen (Turonian-Coniacian) Formations Northeastern Russia.During Santonian-Maastrichtian only entire forms were distributed. The variability of epidermal characters is insignificant. The most variable characters are degree of undulation of the anticlinal cell walls, degree of development of cuticular thickenings and number of stomata on adaxial epidermises and number of trichomes on of abaxial and adaxial epidermises. The specific diagnosis of this species was emended. Remains of G. pilifera occur in allochtonous taphocenosis together with other plants characteristic to riparian habitats. Probably, this species was confined to river valleys and was not connected with swamp environments.Paleoecological implication of great number of papillae and trichomes is steel unclear. Emended diagnosis. Leaves broadly fan-shaped, entire with undulate upper margin with several shallow incisions, or, more rarely, dissected into several wide lobes with rounded or truncate apices. Leaves amphistomatic. Anticlinal cell walls of adaxial epidermis sinuous with amplitude up to 2–3 μm; in costal zones sometimes slightly sinuous or straight. Periclinal walls with cuticular dome-shaped thickenings and rare trichomes. Number and development of cuticular thickenings vary in different areas of leaf lamina and in different leaves. Weak development of thickenings usually correlates with increased number of trichomes. Stomata at abaxial epidermis rare; the papillae of subsidiary cells do not cover the stoma completely. Anticlinal cell walls of abaxial epidermis slightly sinuous or straight. Periclinal walls usually with papillae (12-20 μm long), more rarely, smooth. Trichomes (up to 60–100 μm long) occur rather often. Big trichomes usually consist of 2-3 cells. Stomata at adaxial epidermis orientated irregularly, without formation of regular rows, surrounded by five to seven subsidiary cells. Each subsidiary cell bears a proximal papilla up to 15–25 μm long. These papillae completely cover the stoma.

Molecular and morphological data support the transfer of the monotypic Iranian genus Alococarpum to Prangos (Apiaceae)

Phytotaxa ◽  
2017 ◽  
Vol 299 (2) ◽  
pp. 223 ◽  
Author(s):  
DMITRY F. LYSKOV ◽  
TAHIR H. SAMIGULLIN ◽  
MICHAEL G. PIMENOV
Keyword(s):  
Molecular Analysis ◽  
Morphological Data ◽  
Morphological Evidence ◽  
Vascular Bundles ◽  
Monotypic Genus ◽  
Diagnostic Characters ◽  
Data Support

Based on molecular and morphological evidence, the monotypic genus Alococarpum endemic to Iran has been transferred to the genus Prangos (as P. eriantha (DC.) Lyskov & Pimenov comb. nov.). The main diagnostic characters of fruits (shape of endosperm, division of mesocarp, presence of cyclic vittae and diffuse vascular bundles) are the same both in Prangos and Alococarpum. Our molecular analysis of nrITS/ETS markers also supported the monophyly of Prangos including Alococarpum.

scholarly journals The comparative analysis of anatomical traits of four largefruited hazelnut cultivars showing different susceptibility to filbert aphid (Myzocallis coryli Goetze) feeding

2012 ◽  
Vol 59 (2) ◽  
pp. 69-83
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Magdalena Gantner ◽  
Jadwiga Kostrzewska-Kuczumow
Keyword(s):  
Cross Sections ◽  
Cell Walls ◽  
Leaf Blade ◽  
Susceptible Cultivar ◽  
Abaxial Epidermis ◽  
Adaxial Epidermis ◽  
Aphid Feeding ◽  
Main Vein ◽  
Scanning Electron ◽  
Made In

Investigations related to morphological and anatomical traits of leaves of four largefruited hazelnut (<i>Corylus</i> L.) cultivars characterised by different susceptibility to filbert aphid (<i>Myzocallis coryli</i> Goetze) feeding. The following parameters were measured: the thickness of leaf blade, the number of stomata, the length of secretory and mechanical hairs and their density on the leaf, the thickness of adaxial and abaxial epidermis and the thickness of their external cell walls. Observations of cross sections of the leaves were made in a light microscope and the surface of the adaxial epidermis was analysed in a scanning electron microscope. It was shown that leaves of the cultivars susceptible to <i>M. coryli</i> feeding had the thinnest leaf blade, especially in the main vein, and many more stomata. Besides, the cultivar most resistant to filbert aphid feeding, White Filbert, was marked by the largest height of the adaxial epidermis cells and the strongest striation of the cuticle in abaxial epidermis. On leaves of this cultivar, the number of mechanical hairs was the highest, while the lowest number of them was noted on Wonder from Bollwiller, the most susceptible cultivar.

Non-cellulosic structural polysaccharides in algal cell walls I. Xylan in siphoneous green algae

1964 ◽  
Vol 160 (980) ◽  
pp. 293-313 ◽  
Keyword(s):  
Relative Humidity ◽  
Cell Walls ◽  
Marine Algae ◽  
Transverse Section ◽  
Algal Cell ◽  
Repeat Distance ◽  
X Ray ◽  
Face View ◽  
Half Turn ◽  
Parallel Arrays

The cell walls of a number of marine algae, namely species of Bryopsis, Caulerpa, Udotea, Halimeda and Penicillus and of one freshwater alga, Dichotomosiphon , are examined using both chemical and physical techniques. It is shown that, with the possible exception of Bryopsis , cellulose is completely absent and that the walls contain instead β -l,3-linked xylan as the structural polysaccharide. Bryopsis contains, in addition, a glucan which is most abundant in the outer layers of the wall and which stains like cellulose. The xylan is microfibrillar but the microfibrils are more strongly adherent than they are in cellulose, and in some species appear in the electron microscope to be joined by short crossed rod-like bodies. The orientation of the microfibrils is found to vary, ranging from a net tendency to transverse orientation through complete randomness to almost perfect longitudinal alinement. The microfibrils are negatively birefringent, so that all walls seen in optical section, and all parallel arrays of microfibrils whether in face view or in section (except strictly transverse section) are negatively birefringent. With Bryopsis , the negative birefringence in face view is overcompensated by the positive birefringence of the incrusting glucan so that the true birefringence of the crystalline polysaccharide is observed only after the glucan is removed. The X-ray diagram of parallel arrays of microfibrils as found, for instance, in Penicillus dumetosus shows that the xylan chains are helically coiled, in harmony with the negative birefringence. It is deduced that the microfibrils consist of hexagonally packed, double-stranded helices. The diameter of the helices increases with increasing relative humidity, as water is taken into the lattice, from 13.7 Å in material dried over phosphorus pentoxide to a maximum of 1.54 Å at 65 % relative humidity when the xylan contains 30 % of its weight as water. The repeat distance along the helix axis ranges from 5.85 Å (dry) to 6.06 Å (wet), the length of a half turn of each helix containing three xylose residues. The incrusting substances in these walls often include a glucan which is said also to be 1,3-linked. The significance of the extensive differences between this xylan and cellulose are examined both as regards some of the physical properties of the respective cell walls and in relation to the taxonomic position of these plants.

scholarly journals Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger and Brasilicereus Backeberg

2007 ◽  
Vol 21 (4) ◽  
pp. 813-822 ◽  
Author(s):  
Patricia Soffiatti ◽  
Veronica Angyalossy
Keyword(s):  
Secondary Xylem ◽  
Sieve Tube ◽  
Vascular Bundles ◽  
Campos Rupestres ◽  
Espinhaço Range ◽  
Diagnostic Characters ◽  
Bordered Pits ◽  
Companion Cells ◽  
Southern Bahia ◽  
Perforation Plates

(Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger wâBrasilicereus Backeberg). Arrojadoa, Stephanocereus and Brasilicereus are endemic Brazilian Cereeae, occurring along the Espinhaço Range, in the campos rupestres, cerrados and caatingas, from northern Minas Gerais to southern Bahia. The genera are columnar, erect to semi-erect cacti, except for one species, A bahiensis, which is globose. This study describes the anatomy of dermal, fundamental and vascular systems, aiming to find diagnostic characters for the genera and species. Basal portions of stems were sectioned transversely and longitudinally, and stained with Astrablue and Safranin. The species share a uniseriate epidermis, with thick cuticle; well developed collenchymatic hypodermis, containing prismatic crystals; cortex with numerous mucilage cells, druses and vascular bundles; outside cortex as a palisade parenchyma; periderm composed of lignified cork cells alternating with suberized cells; pheloderm consisting of a few layers of thin-walled cells; phloem composed of solitary or multiple of two to three sieve tube elements, companion cells, axial and radial parenchyma; secondary xylem with solitary to multiple vessels, with simple perforation plates and alternate bordered to semi-bordered pits; axial parenchyma scanty vasicentric to incomplete; libriform septate fibres; large rays. Unlignified parenchyma is seen in the secondary xylem, varying from a few cells to bands among axial and radial elements. The following are considered diagnostic characters: the shape of lignified phellem cells, cubic to radially elongate, which individualizes S. leucostele; an underdeveloped hypodermis and the occurrence of sclereids in the cortex are exclusive to Brasilicereus markgrqfii.

scholarly journals Epidermis structure in Mesembryanthemaceae

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 937-937
Author(s):  
H. -D. Ihlenfeldt
Keyword(s):  
Cell Walls ◽  
Climatic Conditions ◽  
Radiation Balance ◽  
Outer Cell ◽  
Extreme Conditions ◽  
Prominent Feature ◽  
Oxalate Crystals ◽  
Different Types ◽  
Bladder Cells ◽  
Epidermis Structure

The Mesembryanthemaceae, which inhabit the deserts and semi-deserts of Southern Africa, exhibit two very different types of epidermis. The first is characterized by thick outer cell walls encrusted by oxalate crystals, a thick cuticle and thick wax layers. In the second type, the epidermal cells exhibit only very thin outer cell walls, not encrusted by oxalate crystals, a very thin cuticle, and wax layers are poorly developed; the most prominent feature of this type is the occurrence of huge idioblasts often protruding as ‘bladder cells’. With regard to the climatic conditions in the native habitats this type of epidermis must be called ‘abnormal’. Both types of epidermis may form sculptures of three distinct size classes, which are not necessarily homologous. The function of these sculptures is still poorly understood. There is evidence that the sculptures influence the optical properties of the surfaces and thereby the radiation balance (and heat stress) of the leaves.From recent research, it has become evident that the two different types of epidermis are the anatomical expression of two different strategies for survival under extreme conditions. Species with the idioblast type of epidermis exhibit a strategy that might be called ‘opportunistic’. These species have developed a mechanism of gaining water from the atmosphere during the night under favourable conditions. There are indications that the idioblasts are involved in this mechanism.

Further Studies of Lung Parasites (Nematoda) From Australian Marsupials.

1984 ◽  
Vol 32 (2) ◽  
pp. 283 ◽  
Author(s):  
DM Spratt
Keyword(s):  
New South ◽  
Single Species ◽  
Northern Territory ◽  
Trichosurus Vulpecula ◽  
Monotypic Genus ◽  
New Host ◽  
Phascolarctos Cinereus ◽  
Histological Sections ◽  
South Wales ◽  
Host Parasite

Seven new taxa in two families of metastrongyloid nematodes are described from the lungs of five host species belonging to the Dasyuridae, Phalangeridae and Macropodidae. Filaroides (Filaroides) athertonensis, sp. nov., (Filaroididae) is described from Thylogale stigmatica Gould in north Queensland. The following species of Marsupostrongylus Mackerras & Sandars, 1953, (Angiostrongylidae) are described as new: M. parallelus, sp. nov., from Satanellus hallucatus (Could) in the Northern Territory; M. pseudominesi, sp. nov., from Trichosurus vulpecula johnstonii (Ramsay) in north Queensland; M. vandiemeni, sp. nov., from macro pus rufogriseus rufogriseus (Desmarest) in Tasmania; and M. wallabiae, sp. nov., from Wallabia bicolor (Desmarest) and Macropus rufogriseus banksianus (Quoy & Gaimard) in New South Wales. To the formerly monotypic genus Filostrongylus Mackenas, 1955, (Angiostrongylidae) is added F. tridendriticus, sp. nov., described from Trichosurus vulpecula (Kerr) in Tasmania. The genus Cosmostrongylus (Angiostrongylidae) is described as new, with a single species C. conspectus, sp. nov., from Thylogale stigmatica Gould in north Queensland. Durikainema sp. (Muspiceoidea: Robertdollfusidae) is diagnosed in histological sections of the lungs of Phascolarctos cinereus (Goldfuss), Macropus agilis (Could) and M. giganteus Shaw. Keys to the genera of lung parasites and to all species of Filaroides, Marsupostrongylus and Filostrongylus known from Australian marsupials, new host and new geographic records of known taxa, and a host-parasite list of lung parasites of Australian marsupials, including those known only from histological sections of lung tissue, are provided.

Leaf anatomy of the South African Danthonieae (Poaceae). III. Merxmuellera stricta

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 191-198 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
Environmental Factors ◽  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Variable Species ◽  
Morphological Differences

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera stricta (Schrad.) Conert is described and illustrated. In this variable species four distinct anatomical “forms” are recognized viz. the typical  M. stricta form, the Cathedral Peak form, the Drakensberg form and the alpine form. The alpine and Cathedral Peak forms have recently been described as M. guillarmodiae Conert (1975). The degree of anatomical differentiation of these “forms” resembles the situation described in M. disticha (Nees) Conert (Ellis, 1980). Populations of both M. stricta and M. disticha from the Drakensberg mountains display extensive anatomical diversification which appears to be correlated with environmental factors. In addition, morphological differences are exhibited as well and the anatomical “forms” of M. stricta probably warrant taxonomic recognition.

Leaf anatomy of the South African Danthonieae (Poaceae). II. Merxmuellera disticha

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 185-189 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Taxonomic Status ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Environmental Requirements

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera disticha (Nees) Conert is described and illustrated. Three distinct anatomical “forms” are recognized viz. typical M. disticha, the Drakensberg form and the alpine bog form. These three anatomical groups also appear to have differing environmental requirements and probably warrant taxonomic status.

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