New occurrences of trimerophytes from the Devonian of eastern Canada

1978 ◽  
Vol 56 (24) ◽  
pp. 3052-3068 ◽  
Author(s):  
Jeffrey B. Doran ◽  
Patricia G. Gensel ◽  
Henry N. Andrews
Keyword(s):  
Middle Devonian ◽  
Early Stage ◽  
Lateral Branch ◽  
Main Axis ◽  
Eastern Canada ◽  
Morphologic Variation ◽  
Lateral Branches ◽  
Branch Type ◽  
Established Species ◽  
New Occurrences

Pertica dalhousii n.sp. is described from the late Lower or early Middle Devonian of New Brunswick. The plant is known from a central axis with spirally arranged, mostly dichotomous lateral branches. Some lateral branches terminate in erect clusters of 32–128 fusiform sporangia. Spores are circular, trilete, with a detachable outer sculptured layer, and resemble the dispersed spore genus Apiculiretusispora Streel. A trimerophyte from Gaspé is described and provisionally designated as cf. Pertica sp.; the specimens are too incompletely preserved to be assigned to any established species, but they add further information about morphologic variation in the genus Pertica.With the addition of new plant types referable to the trimerophytes, distinctions between genera and species are becoming less readily apparent, supporting the suggestion that the trimerophytes are a group of closely related plants in which considerable evolution was occurring in late Lower and Middle Devonian times. Additionally, these plants appear to represent an early stage in the differentiation of a distinct main axis – lateral branch type of organizaiton that probably led to the later evolution of megaphyllous leaves.

Structure and development of shoots in Cytisus scoparius

1990 ◽  
Vol 68 (12) ◽  
pp. 2576-2582 ◽  
Author(s):  
Tian Su Zhou ◽  
Noboru Hara
Keyword(s):  
Growing Season ◽  
Lateral Branch ◽  
Main Axis ◽  
Leaf Primordia ◽  
Axillary Meristem ◽  
Cytisus Scoparius ◽  
Lateral Branches ◽  
Winter Buds ◽  
The Relationship ◽  
Characteristic Manner

The vegetative winter bud of Cytisus scoparius Link contains about nine leaf primordia. It grows into a main axis during the current growing season. At the end of the growing season, a shoot system consisting of a main axis and many lateral branches is formed. The lateral branch originates as a primordium when winter buds expand in spring, from the axil between the sixth and eighth leaves (numbered from the base of the bud), following which the succeeding primordia of branches appear sequentially. These lateral primordia continue to extend synchronously with the extension of the main axis during the growing season. By the end of the growing season, the lateral branches have reached various lengths and are arranged in a somewhat characteristic manner on the main axis; the relatively long branches are often located on the portions with ternately compound leaves and are associated with the vigorous elongation of the main axis. The relationship between the growth of the lateral branches and the main axis is discussed. Key words: axillary meristem, Cytisus, proleptic shoot, sylleptic shoot.

scholarly journals Growth, fructification and plastochron index of different branches in the crown of the husk tomato (Physalis ixocarpa Brot.)

2014 ◽  
Vol 54 (3) ◽  
pp. 195-206 ◽  
Author(s):  
Juan M. Brito ◽  
Leszek S. Jankiewicz ◽  
Victor M. Orduna ◽  
Francisco C. Escobar ◽  
Luis M. Covarrubias
Keyword(s):  
Lateral Branch ◽  
Main Axis ◽  
Flower Bud ◽  
Vegetative Period ◽  
Short Period ◽  
Plant Produce ◽  
Lateral Branches ◽  
Sympodial Growth ◽  
Plastochron Index ◽  
Husk Tomato

The husk tomato (<em>Physalis ixocarpa</em> Brot.) is commonly cultivated in Central Mexico for its fruits. The plants of cv. 'Rendidora' show sympodial growth after forming 3-5 internodes in the main axis. From there on, each internode is terminated with a node having one flower bud, one leaf and 2 branches (dichasium type of branching). With the exclusion of the first 3 bifurcations which initiate 4 equal apparent main branches of the plant, each subsequent bifurcation has unequal ramifications: a stronger one which prolongs the apparent main branch, and a weaker one which serves as the origin of an apparent lateral branch. The apparent lateral branches form smaller internodes but these internodes require more time for their growth which is the reason that the plastochron lasts longer in the apparent lateral branches. By forming a smaller number of internodes in the same period of time, the apparent lateral branches reach a lower value of the plastochron index. All apparent lateral branches of a plant produce a greater total number of fruits, but a large proportion of them abscise. Due to this, the harvested fruits come principally from the apparent main branches. The phenology of the husk tomato plant is described. Its short period of development makes possible its cultivation in regions with a limited vegetative period.

The Branchless Gene C lbl in Watermelon Encoding a Terminal Flower 1 Protein Regulate S the Number of Lateral Branch

2021 ◽  
Author(s):  
Junling Dou ◽  
Huihui Yang ◽  
Dongling Sun ◽  
Sen Yang ◽  
Shouru Sun ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Recessive Gene ◽  
Crop Productivity ◽  
Lateral Branch ◽  
Coding Region ◽  
Terminal Flower ◽  
Apical Bud ◽  
Terminal Flower 1 ◽  
Branch Development ◽  
Lateral Branches

Abstract Lateral branching is one of the most important traits, which directly determines plant 27 architecture and crop productivity. Commercial watermelon has the characteristics of multiple 28 lateral branches, and it is time-consuming and labor costing to manually remove the lateral 29 branches in traditional watermelon cultivation. In our present study, a lateral branchless trait was 30 identified in watermelon material W CZ, and genetic analysis revealed that it was controlled by a 31 single recessive gene, which named as Clbl . A bulked segregant sequencing (BSA seq) and 32 linkage analysis was conducted to primarily mapping of Clbl on watermelon chromosome 4 33 Next-generation sequencing aided marker discovery and a large mapping population consisting of 34 1406 F 2 plants was used to further mapped the Clbl locus into a 9011 bp candidate region which 35 harbored only one candidate gene Cla018392 encoding a TERMINAL FLOWER 1 gene. Sequence 36 comparison of Cla018392 between two parental lines revealed that there was a SNP detected from 37 C to A in the coding region in the branchless inbred line WCZ , which resulted in a mutation of 38 Alanine (GCA) to Glutamate (GAA) at the fourth exon A dCAPS marker was developed from the 39 SNP locus, which was co-segregated with the branchless phenotype in both BC 1 and F 2 population, 40 and it was also further validated in 152 natural watermelon accessions. qRT PCR and in situ 41 hybridization showed that the expression levels of Cla0 18392 was significantly reduced in the 42 axillary bud and apical bud in the branchless line WCZ Ectopic expression of ClTFL1 in 43 Arabidopsis showed an increased number of lateral branches. The results of this study will be 44 useful for better understanding the molecular mechanism of lateral branch development in 45 watermelon and for the development of marker-assisted selection (MAS) for new branchless 46 watermelon cultivars.

Lateral branch blocks

2021 ◽  
pp. 75-82
Author(s):  
Benjamin K. Homra ◽  
Yashar Eshraghi ◽  
Maged Guirguis
Keyword(s):  
Radiofrequency Ablation ◽  
Local Anesthetic ◽  
Sacroiliac Joint ◽  
Joint Pain ◽  
Lateral Branch ◽  
Ultrasound Technique ◽  
Posterior Aspect ◽  
Sacroiliac Joint Pain ◽  
Lateral Branches

The posterior sacral network is a complex meshwork of lateral branches of the dorsal sacral rami that innervate the posterior aspect of the sacroiliac joint. Pain arising from this joint can be diagnostically targeted using either a fluoroscopic or ultrasound technique to determine if the patient would benefit from radiofrequency ablation of the lateral branches. Injecting local anesthetic near the dorsal foramina using these techniques will temporarily block the transmission of pain by the lateral branches from the sacroiliac joint. This chapter covers the anatomy of the posterior sacral network, discusses the details of the two techniques for lateral branch blocks and evidence for their utility, provides information about the risks and contraindications associated with the techniques, and concludes by discussing the implications of the procedure.

Arachnoxylon from the Middle Devonian of southwestern Virginia

1983 ◽  
Vol 61 (4) ◽  
pp. 1283-1299 ◽  
Author(s):  
William E. Stein Jr. ◽  
David C. Wight ◽  
Charles B. Beck
Keyword(s):  
Middle Devonian ◽  
Main Axis ◽  
Supplementary Information ◽  
Monotypic Genus ◽  
Primary Xylem ◽  
New Material ◽  
Shale Formation ◽  
Definition Of ◽  
A Minor ◽  
First Time

Eight specimens from the Middle Devonian Purcell Member of the Millboro Shale Formation in southwestern Virginia conform to a recent definition of the previously monotypic genus Arachnoxylon. The new material provides supplementary information on several tissue regions of the main axis, including evidence on variability in the structure of the protoxylem, and on departure of the large, or "major" traces. In addition, evidence is provided here for the first time on a discrete region, immediately adjacent to the primary xylem, containing probable conducting elements of the primary phloem, on the structure of the epidermis, and on the presence of multicellular superficial emergences. Although clearly assignable to Arachnoxylon, all but one of our specimens vary significantly from previous specimens in the genus in several features which may be interpreted as relating directly or indirectly to size. It is possible that all specimens in Arachnoxylon represent portions of a single kind of plant. However, organic connection between the large and small forms has not been demonstrated. We elect, therefore, to establish A. minor sp. n. for the smaller specimens.

A large arthropod trackway from the Gaspé Sandstone Group (Middle Devonian) of eastern Canada

1998 ◽  
Vol 35 (10) ◽  
pp. 1116-1122 ◽  
Author(s):  
Simon J Braddy ◽  
Andrew RC Milner
Keyword(s):  
Shallow Water ◽  
Middle Devonian ◽  
Eastern Canada

A large arthropod trackway from the Cap-aux-Os Member of the Battery Point Formation (Gaspé Sandstone Group, Middle Devonian), from the Baie de Gaspé, eastern Canada, is described and assigned to the ichnotaxon Palmichnium (= Paleohelcura) antarcticum (Gevers et al., 1971). A large stylonurid eurypterid or scorpion is considered the most likely producer. A shallow-water marginal fluvial environment is inferred as the setting, the animal making a transition from walking to swimming along the course of the trackway.

Cone initiation and development before dormancy in yellow cedar (Chamaecyparis nootkatensis)

1974 ◽  
Vol 52 (9) ◽  
pp. 2075-2084 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder
Keyword(s):  
Mitotic Activity ◽  
Lateral Branch ◽  
Leaf Primordia ◽  
Day Length ◽  
Chamaecyparis Nootkatensis ◽  
Seed Cone ◽  
Cone Development ◽  
Cone Apex ◽  
Lateral Branches ◽  
Pollen Cone

Vegetative shoots initiate leaves and lateral branches continuously from mid-April until the end of September. No buds with bud scales are formed and the vegetative apex is enclosed by leaf primordia at various stages of development. Pollen cones are initiated on proximal vegetative shoots during a 3-week period from mid-June to early in July. Transition to a pollen-cone apex is marked by an increase in mitotic activity in the apex and by the formation of a lateral branch in the axil of one of the last-formed leaf primordia, causing the apex to appear to branch dichotomously. The lateral branch remains at the base of the pollen cone and may resume growth the next year after the pollen cone is shed. Pollen-cone development continues until the end of September. Meiosis occurs during the last 2 weeks of August, and pollen develops during September. Seed cones are initiated on newly formed, distal axillary vegetative shoots during a 3-week period from late June to mid-July. Transition to a seed-cone apex is marked by an increase in mitotic activity followed by bract-scale initiation. Usually three ovules are initiated in the axil of each bract scale. Seed-cone development is complete by early September and the seed cones become dormant. The pattern of reproduction in yellow cedar is compared to other conifers and the possible relationships are discussed between time of cone initiation, sexuality of cones, and day length.

Anatomical study of superior cluneal nerve entrapment

2013 ◽  
Vol 19 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Hiroshi Kuniya ◽  
Yoichi Aota ◽  
Tomoyuki Saito ◽  
Yoshinori Kamiya ◽  
Kengo Funakoshi ◽  
...  
Keyword(s):  
Iliac Crest ◽  
Anatomical Study ◽  
Anatomical Variations ◽  
Lateral Branch ◽  
Medial Branch ◽  
Low Back ◽  
Thoracolumbar Fascia ◽  
Recent Clinical Study ◽  
Lateral Branches ◽  
The Right

Object Entrapment of the superior cluneal nerve (SCN) in an osteofibrous tunnel in the space surrounded by the iliac crest and the thoracolumbar fascia is a cause of low-back pain (LBP). Several anatomical and surgical reports describe SCN entrapment as a cause of LBP, and a recent clinical study reported that patients with suspected SCN disorder constitute approximately 10% of the patients suffering from LBP and/or leg symptoms. However, a detailed anatomical study of SCN entrapment is rare. The purpose of this study was to investigate the courses of SCN branches and to ascertain the frequency of SCN entrapment. Methods Branches of the SCN were dissected in 109 usable specimens (54 on the right side and 55 on the left side) obtained in 59 formalin-preserved cadavers (average age at death 84.8 years old). All branches were exposed at the points where they perforated the thoracolumbar fascia. The presence or absence of an osteofibrous tunnel was ascertained and, if present, the entrapment of the branches in the tunnel was determined. Results Of 109 specimens, 61 (56%) had at least 1 branch running through an osteofibrous tunnel. Forty-two medial (39%), 30 intermediate (28%), and 14 lateral (13%) SCN branches passed through such a tunnel. Of these, only 2 medial branches had obvious entrapment in an osteofibrous tunnel. There were several patterns for the SCN course through the tunnel: medial branch only (n = 25), intermediate branch only (n = 11), lateral branch only (n = 4), medial and intermediate branches (n = 11), medial and lateral branches (n = 2), intermediate and lateral branches (n = 4), and all branches (n = 4). Conclusions Several anatomical variations of the running patterns of SCN branches were detected. Entrapment was seen only in the medial branches. Although obvious entrapment of the SCN is rare, it may cause LBP.

Mechanical and photosynthetic constraints on the evolution of plant shape

Paleobiology ◽  
1984 ◽  
Vol 10 (1) ◽  
pp. 79-101 ◽  
Author(s):  
Karl J. Niklas ◽  
Vincent Kerchner
Keyword(s):  
Photosynthetic Efficiency ◽  
Growth Habit ◽  
Three Dimensional ◽  
Main Axis ◽  
Moment Arm ◽  
Total Moment ◽  
Moment Arms ◽  
Branching Patterns ◽  
Upper Silurian ◽  
Lateral Branches

A computer model is presented which is capable of calculating both the photosynthetic efficiency (I) of any specified plant shape and the stress related to the total moment arm (M) imposed on vertical branching patterns. Computer simulations indicate that a flattened plant thallus and an erect branching growth habit are two plant shapes capable of optimizing photosynthetic efficiency during indeterminate growth. These two morphologies have geometric analogues in the dorsiventral thalli of some bryophytes and in the vertical axes of mosses and tracheophytes, respectively.Extension of the model to complex, three-dimensional branching patterns indicates that I and I/M are maximized when branching is overtopped (treelike, with lateral branches on a main axis) and when lateral branching systems are planated (frondlike). Geometric alterations of branching patterns that result in optimization of I and I/M can be simulated by computer and are shown to be similar to morphologic alterations attending the early evolution of vascular land plants. It is suggested that a number of major evolutionary trends seen in Upper Silurian to Upper Devonian times can be expressed in terms of optimizing the display of photosynthetic tissues (I) or the balance between photosynthetic efficiency and incurred moment arms (I/M).

A silicified semiaquatic dicotyledon from the Eocene Allenby Formation of British Columbia

1973 ◽  
Vol 51 (7) ◽  
pp. 1373-1377 ◽  
Author(s):  
Coleman R. Robison ◽  
Christopher P. Person
Keyword(s):  
British Columbia ◽  
Adventitious Roots ◽  
Single Layer ◽  
Salient Feature ◽  
Anatomical Structure ◽  
Main Axis ◽  
Epidermal Cells ◽  
Coal Basin ◽  
Lateral Branches ◽  
Air Cavities

A silicified dicotyledon rhizome is described from the Eocene Allenby Formation of the Princeton Coal Basin, British Columbia. The primary and secondary vascular tissues of the rhizome form a narrow cylinder around a broad, parenchymatous pith. The rhizome's salient feature is a wide cortex in which there are numerous air cavities. In most specimens the cortex is surrounded by a single layer of epidermal cells but in some there is evidence of periderm initiation. Small lateral branches are borne on the main axis, and both the main and lateral axes bear broad, clasping leaf bases and adventitious roots. The affinities of this rhizome are presently unknown, but its anatomical structure is indicative of a semiaquatic plant.

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