A monograph of Dolerotheca Halle, and related complex permineralised medullosan pollen organs

1986 ◽  
Vol 77 (1) ◽  
pp. 47-79 ◽  
Author(s):  
Gar W. Rothwell ◽  
Donald A. Eggert
Keyword(s):  
North America ◽  
Internal Structure ◽  
Vascular System ◽  
Vascular Bundles ◽  
Ground Tissue ◽  
Type Specimens ◽  
Histological Features ◽  
Folding Pattern ◽  
Distal Surface ◽  
Complex Forms

ABSTRACTNumerous permineralised, complex medullosan pollen organs are described from Middle and Upper Pennsylvanian sediments of North America. Together with a reinvestigation of type specimens for the previously described species, these provide the basis for fully characterising internal structure and external morphology, and for recognising structural homologies among all medullosan synangia. All medullosan pollen organs, simple and complex, can be interpreted as consisting of sporangial tubes that are embedded in parenchymatous and sclerenchymatous ground tissue, and that have vascular bundles within the parenchymatous tissue. The sporangial tubes are arranged in a single series, usually a ring, with parenchymatous ground tissues and vascular bundles to the outside of the ring and sclerenchymatous ground tissue to the inside of the ring. In the larger, complex forms the ring is plicately folded and there may be a centrally-placed hollow in the distal surface. Differences in morphology, in the folding pattern of the rings, in the structure (or absence) of a distal hollow, and in architecture of the major vascular system are employed to delimit genera. Size and shape of the organ, histological features, numbers of sporangia, and presence or absence of lacunae are used to delineate species. Currently recognised genera are Dolerotheca Halle, Sullitheca Stidd et al., Stewartiotheca Eggert and Rothwell, and Bernaultia gen. nov.

Early Paleozoic Hyolitha from North America: reexamination of Walcott's and Resser's type specimens

1988 ◽  
Vol 62 (2) ◽  
pp. 218-233 ◽  
Author(s):  
John Mark Malinky
Keyword(s):  
North America ◽  
Lower Cambrian ◽  
Type Species ◽  
New Genus ◽  
Early Paleozoic ◽  
Type Specimens ◽  
Middle Cambrian ◽  
Upper Cambrian ◽  
New Family ◽  
The Family

Concepts of the family Hyolithidae Nicholson fide Fisher and the genera Hyolithes Eichwald and Orthotheca Novak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated. Hyolithes encompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept of Orthotheca includes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.Eighteen species of Hyolithes and one species of Orthotheca from the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens of H. similis Walcott from the Lower Cambrian of Newfoundland, H. whitei Resser from the Lower Cambrian of Nevada, H. billingsi Walcott from the Lower Cambrian of Nevada, H. gallatinensis Resser from the Upper Cambrian of Wyoming, and H. partitus Resser from the Middle Cambrian of Alabama indicates that none of these species represents Hyolithes. Hyolithes similis is here included under the new genus Similotheca, in the new family Similothecidae. Hyolithes whitei is designated as the type species of the new genus Nevadotheca, to which H. billingsi may also belong. Hyolithes gallatinensis is referred to Burithes Missarzhevsky with question, and H. partitus may represent Joachimilites Marek. The type or types of H. attenuatus Walcott, H. cecrops Walcott, H. comptus Howell, H. cowanensis Resser, H. curticei Resser, H. idahoensis Resser, H. prolixus Resser, H. resseri Howell, H. shaleri Walcott, H. terranovicus Walcott, and H. wanneri Resser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types of H.? corrugatus Walcott and “Orthotheca” sola Resser does not support placement in the Hyolitha; the affinities of these species are uncertain.

Reassessing species boundaries in the Syagrus glaucescens complex (Arecaceae) using leaf anatomy

Botany ◽  
2021 ◽  
pp. 379-387
Author(s):  
D.H.T. Firmo ◽  
S.A. Santos ◽  
M.E.M.P. Perez ◽  
P. Soffiatti ◽  
B.F. Sant’Anna-Santos
Keyword(s):  
Species Identification ◽  
Leaf Anatomy ◽  
Vascular System ◽  
Identification Key ◽  
Species Boundaries ◽  
Vascular Bundles ◽  
Geographical Isolation ◽  
Species Occurrence ◽  
Species Diagnosis ◽  
High Degree

The Syagrus glaucescens complex comprises three species: Syagrus glaucescens Glaz. ex Becc., Syagrus duartei Glassman, and Syagrus evansiana Noblick. Recently, a new population of S. evansiana that possesses a high degree of endemism was reported in the Serra do Cabral mountain. Here we intend to study the leaf anatomy of the S. glaucescens complex and confirm whether this newly found population (from now on called Syagrus aff. evansiana) belongs to S. evansiana or not. Specimens were collected to investigate their leaf anatomy, which showed distinct differences between S. aff. evansiana and S. evansiana. The midrib anatomy revealed novelties for the S. glauscecens complex, proving useful for species diagnosis. Features such as accessory vascular bundles around the vascular system of the midrib and the number of collateral bundles are diagnostic for species identification. In addition, morphological and anatomical analyses indicated a correlation with the species occurrence. We found greater similarity between S. glaucescens and S. duartei, while S. evansiana and S. aff. evansiana are more alike. Here, we propose a new identification key based only on the leaf anatomy. Despite their morphological similarities, S. aff. evansiana and S. evansiana presented differences in leaf anatomy, which — when associated with their geographical isolation — suggests a fourth taxon in the complex.

scholarly journals Morphology and anatomy of leaf mine in Richterago riparia Roque (Asteraceae) in the campos rupestres of Serra do Cipó, Brazil

2002 ◽  
Vol 62 (1) ◽  
pp. 179-185 ◽  
Author(s):  
G. F. A. MELO DE PINNA ◽  
J. E. KRAUS ◽  
N. L. de MENEZES
Keyword(s):  
Host Plant ◽  
Vascular System ◽  
Glandular Trichomes ◽  
Protective Layer ◽  
Vascular Bundles ◽  
Campos Rupestres ◽  
Structural Alterations ◽  
Serra Do Cipó ◽  
Phenolic Substances

The leaf mine in Richterago riparia is caused by a lepidopteran larva (lepidopteronome). The leaves of R. riparia show campdodrome venation; the epidermis is unistratified, with stomata and glandular trichomes in adaxial and abaxial surfaces. The mesophyll is bilateral and the vascular system is collateral. During the formation of the mine, the larva consumes the chlorenchyma of the mesophyll and the smaller vascular bundles (veins of third and fourth orders). Structural alterations in the tissues of the host plant were not observed, except for the formation of a wound meristem and the presence of cells with phenolic substances next to the mine. Three cephalic exuviae of the miner were found in the mesophyll. This lepidopteronome is parenchymatic and the epidermis remains intact, but forms a protective layer for the mining insect.

scholarly journals Presence of Xylella fastidiosa in Sweet Orange Fruit and Seeds and Its Transmission to Seedlings

2003 ◽  
Vol 93 (8) ◽  
pp. 953-958 ◽  
Author(s):  
W.-B. Li ◽  
W. D. Pria ◽  
P. M. Lacava ◽  
X. Qin ◽  
J. S. Hartung
Keyword(s):  
Vascular System ◽  
Sweet Orange ◽  
Xylella Fastidiosa ◽  
Germination Rate ◽  
Citrus Fruit ◽  
Vascular Bundles ◽  
Specific Amplification ◽  
Root Grafts ◽  
Citrus Seeds

Xylella fastidiosa, a xylem-limited bacterium, causes several economically important diseases in North, Central, and South America. These diseases are transmitted by sharpshooter insects, contaminated budwood, and natural root-grafts. X. fastidiosa extensively colonizes the xylem vessels of susceptible plants. Citrus fruit have a well-developed vascular system, which is continuous with the vascular system of the plant. Citrus seeds develop very prominent vascular bundles, which are attached through ovular and seed bundles to the xylem system of the fruit. Sweet orange (Citrus sinensis) fruit of cvs. Pera, Natal, and Valencia with characteristic symptoms of citrus variegated chlorosis disease were collected for analysis. X. fastidiosa was detected by polymerase chain reaction (PCR) in all main fruit vascular bundles, as well as in the seed and in dissected seed parts. No visual abnormalities were observed in seeds infected with the bacterium. However, the embryos of the infected seeds weighed 25% less than those of healthy seeds, and their germination rate was lower than uninfected seeds. There were about 2,500 cells of X. fastidiosa per infected seed of sweet orange, as quantified using real-time PCR techniques. The identification of X. fastidiosa in the infected seeds was confirmed by cloning and sequencing the specific amplification product, obtained by standard PCR with specific primers. X. fastidiosa was also detected in and recovered from seedlings by isolation in vitro. Our results show that X. fastidiosa can infect and colonize fruit tissues including the seed. We also have shown that X. fastidiosa can be transmitted from seeds to seedlings of sweet orange. To our knowledge, this is the first report of the presence of X. fastidiosa in seeds and its transmission to seedlings.

A review of the ecology and distribution of Protoribates (Oribatida, Oripodoidea, Haplozetidae) in Alberta, Canada, with the description of a new species

Zootaxa ◽  
2013 ◽  
Vol 3620 (3) ◽  
pp. 483-499 ◽  
Author(s):  
DAVID EVANS WALTER ◽  
SARAH LATONAS
Keyword(s):  
New Species ◽  
North America ◽  
Oribatid Mite ◽  
Gut Contents ◽  
Plant Cell Walls ◽  
Type Specimens ◽  
Peat Soils ◽  
The North ◽  
Opportunistic Predator ◽  
A New Species

The oribatid mite genus Protoribates Berlese (Haplozetidae) is reviewed for North America and the genus diagnosis is revised to account for the North American species, Protoribates robustior (Jacot, 1937) is redescribed and newly reported from western North America and a new species from Alberta is described. Protoribates haughlandae sp. n. is bisexual, heterotridactylous, and lives primarily in the peat soils of fens and bogs. Protoribates robustior is all-female, monodactylous, and occurs primarily in dry forests or in dry, treeless sites dominated by grasses, sedges, and shrubs. Both species feed on fungal hyphae and spores, but P. haughlandae also is an opportunistic predator and/or necrophage of small arthropods and P. robustior gut contents often include material that resembles plant cell walls. Examination of type specimens confirms that Protoribates prionotus (Woolley, 1968) is a junior synonym of the widespread Protoribates lophotrichus (Berlese, 1904). A key to differentiate Lagenobates from Protoribates and to identify the 7 species of the latter that are known or reported from North America is provided.

Comparative chemotaxonomic investigations on amaranthus hybridus l. and Amaranthus spinosus L.

2021 ◽  
Vol 20 (1) ◽  
pp. 91-100
Author(s):  
C. Wahua ◽  
J. Nwikiri
Keyword(s):  
Niger Delta ◽  
Vascular System ◽  
Vascular Bundles ◽  
Stomatal Index ◽  
Amaranthus Hybridus ◽  
Anatomical Studies ◽  
Amaranthus Spinosus ◽  
The Family ◽  
Phytochemical Studies ◽  
Key Words Morphology

The present study is set to investigate the comparative chemotaxonomic investigations on Amaranthus hybridus L. and Amaranthus spinosus L. which belong to the family Amaranthaceae. They are dicots pre-dominantly found in the Niger Delta Tropics, Nigeria. The species are annual erect herbs with flower inflorescences as elongated spikes which are mostly paniculate occurring at ends of branches in globose fashion in axils of leaves.The nodes often have pair of axillary spines. Flowers are small, greenish with male ones at the top while the female ones below the clusters and stem is greenish but often reddish with one-seeded capsule as fruit in Amaranthus spinosus which attains up to 80 ± 20cm in height whereas A. hybridus differ in absence of a pair of axillary spines, the stems are greenish or slightly pinkish which grows up to 100 ± 10cm in height. A. hybridus is more of a vegetable and has alternate phyllotaxi and narrow cuneate base. Fruits from both species are circumscissile capsules and their inflorescences are terminal racemes positioned at their axils with female perianth segments of five. Epidermal studies revealed amphistomatic stomata which is anisocytic  type for both species. The stomatal index for A. spinosus adaxial foliar epidermis is 20% and the abaxial 20% whereas for A. hybridus adaxial is 20% and abaxial foliar stomatal index of 20%. Anatomical studies revealed open vascular system, collenchyma dominating the hypodermis while parenchyma occupied the general cortex and pith regions. A. hybridus has more vascular bundles and trichomes, and wider pith than A. spinosus. Phytochemical studies showed the presence of tannins, saponins, alkaloids, and flavonoids are present in A. spinosus while alkaloids were absent only in A. hybridus. This may be the reason why A. spinosus is used more in tradomedicine than A.hybridus which served more as vegetable. Key Words: Morphology, Anatomy, Phytochemistry, Amaranthus, Amaranthaceae

Vascular System of the Stem of the Wheat Plant. I. Mature State

1972 ◽  
Vol 20 (1) ◽  
pp. 49 ◽  
Author(s):  
JW Patrick
Keyword(s):  
Triticum Aestivum ◽  
Vascular System ◽  
Wheat Plant ◽  
Triticum Aestivum L ◽  
Vascular Bundles ◽  
Vascular Connections ◽  
Main Tiller

The courses of the various vascular bundles in the nodes of the main tiller of Triticum aestivum L. have been reconstructed from anatomical observations of con- secutive serial transverse sections. Of the bundles entering a node (n) from its attached leaf, the first-formed and largest, the median, passes directly through the node to the second node below (n-2), where it bifurcates and fuses with other strands. These continue to node n- 3 before fusing completely with the nodal plexus. The next six bundles to form (laterals) establish some links with bundles from higher leaves in the node of entry, much more extensive connections in node n- 1, and fuse completely with the nodal plexus in node n-2. The next four lateral bundles to differentiate are more extensively linked in node n and fuse completely with the nodal plexus in node n - I . The remaining 16-20 bundles from the leaf (intermediates) follow much the same course but develop more extensive connections with other bundles. The extensive plexus which develops in each node ensures vascular connections between most bundles. The significance of these in transport is briefly discussed.

Kochiella Poulsen, 1927, and Hadrocephalites new genus (Trilobita: Ptychopariida) from the early Middle Cambrian of western North America

2002 ◽  
Vol 76 (1) ◽  
pp. 76-94 ◽  
Author(s):  
Frederick A. Sundberg ◽  
Linda B. McCollum
Keyword(s):  
New Species ◽  
North America ◽  
New Genus ◽  
Western North America ◽  
Type Specimens ◽  
Middle Cambrian ◽  
Informal Group ◽  
Nomen Dubium

Kochaspids are an informal group of ptychopariid trilobites that were both abundant and widespread in the early Middle Cambrian of North America. Based on the reassociation of pygidia and cranidia of some kochaspids, Kochiella Poulsen, 1927, is redefined and Hadrocephalites n. gen. is proposed. Hadrocephalites includes taxa previously assigned by Rasetti and Palmer to Schistometopus Resser, 1938a. Schistometopus is considered nomen dubium. Representatives of Kochiella and Hadrocephalites from the Pioche Shale and Carrara Formation of Nevada are described, including the new species Kochiella rasettii, K. brevaspis, Hadrocephalites lyndonensis, and H. rhytidodes. Other kochaspids previously assigned to Kochaspis Resser, 1935; Eiffelaspis Chang, 1963; Schistometopus; and Kochiella are discussed and some are reassigned. The type specimens of Kochiella augusta (Walcott, 1886); K. crito (Walcott, 1917b); K. chares (Walcott, 1917a); K. mansfieldi Resser, 1939; K. arenosa Resser, 1939; Hadrocephalites carina (Walcott, 1917b), and H. cecinna (Walcott, 1917b) are re-illustrated.

DEVELOPMENTAL STUDIES OF THE APPLE FRUIT IN THE VARIETIES McINTOSH RED AND WAGENER: II. AN ANALYSIS OF DEVELOPMENT

1941 ◽  
Vol 19c (10) ◽  
pp. 371-382 ◽  
Author(s):  
Mary MacArthur ◽  
R. H. Wetmore
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Fruit Size ◽  
Apple Fruit ◽  
Vascular Bundles ◽  
Developmental Studies ◽  
Cell Enlargement ◽  
Ground Tissue ◽  
Fundamental Pattern

Growth in the various tissues of the fruit of a McIntosh Red and a Wagener tree, both self-pollinated, is compared. For several days succeeding pollination no increase in fruit size is apparent. Fertilization is followed by general cell division and cell enlargement. The period of cell division varies with the tissue and with the variety. Final cell size is reached first by the cells of those tissues near the centre of the apple. Impressed upon the fundamental pattern of growth is the localized activity of the primary vascular bundles, the cambia of which add cells to the ground tissue. Angulation in the Wagener is accentuated by this activity. With the exception of cells of the epidermis, final cell size is approximately equal in comparable regions of the two varieties. Differences in regional extent are due to differences in numbers of cells in that region.

Salt-induced changes in the vegetative anatomy of Prosopis strombulifera (Leguminosae)

2004 ◽  
Vol 82 (5) ◽  
pp. 618-628 ◽  
Author(s):  
Herminda Reinoso ◽  
Laura Sosa ◽  
Lucía Ramírez ◽  
Virginia Luna
Keyword(s):  
Vascular System ◽  
Vascular Bundles ◽  
Anatomical Changes ◽  
Metabolic Adaptations ◽  
Tolerant Plants ◽  
Ion Exclusion ◽  
Size Groups ◽  
Induced Changes ◽  
Endodermal Cells ◽  
Early Activity

Seedlings of Prosopis strombulifera (Lam.) Benth. were grown hydroponically in Hoagland's solution with addition of 25 mmol/L NaCl every 48 h until final salt concentrations of 250, 500, and 700 mmol/L were reached. Control plants were grown without salt. Salinity induced anatomical changes in roots (young and mature zones), hypocotyls, young stems, and leaflets. The diameters of the young zone of roots of plants grown in increasing salt concentrations were smaller than those of controls, with reduced number of cortex layers and reduced size of the vascular system. The roots from tolerant plants showed precocious suberization and (or) lignification of the endodermal cells and early activity of the pericycle. Hypocotyl diameter was reduced along with a reduction in secondary phloem. Roots and hypocotyls showed abundant phellem formation. The stem diameter of young tolerant plants was notably diminished and less tissue lignification occurred. In stems and leaflets of treated plants, NaCl stimulated the production of tannins. In the leaflets, vascular bundles were similar in size. Groups of elongated parenchyma cells with many chloro plasts surrounded the bundles. These results suggest that in the absence of secretory organs, the anatomical modifications in this species are related to metabolic adaptations, such as an early development of the endodermal barrier for ion exclusion, to allow survival in high salinity.Key words: Prosopis strombulifera, anatomical changes, hydroponics, NaCl.

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