PRUNUS IN EASTERN CANADA

1940 ◽  
Vol 18c (7) ◽  
pp. 318-346 ◽  
Author(s):  
Herbert Groh ◽  
Harold A. Senn

The distribution of Prunus species in Eastern Canada is of definite economic significance since these species serve as secondary hosts for leaf hoppers and aphids, which are vectors of important virus diseases.A key is presented for the determination of the following native and naturalized species: Prunus spinosa, insititia, domestica, americana, nigra, Persica, pumila, avium, Cerasus, mahaleb, pennsylvanica, serotina, Padus, and virginiana. The detailed distribution of these species is outlined through the citation of herbarium specimens and Canadian Weed Survey records, the ranges of the more important species being mapped.Cultivated and naturalized species are considered to be of little significance in disease transmittal. In potato-growing regions the choke cherry (P. virginiana) which frequents fence-rows is probably the most important species, although the bird cherry (P. pennsylvanica) may also be important on light sandy soils.

1996 ◽  
Vol 74 (2) ◽  
pp. 238-242 ◽  
Author(s):  
B. M. H. Larson ◽  
P. M. Catling

Eleocharis obtusa and Eleocharis ovata are recognized as distinct species or combined in recent taxonomic literature. To assess their morphological relationship and to evaluate all morphological characters potentially useful for their separation, 11 floral and achene characters were measured on 130 eastern Canadian herbarium specimens. Tubercle width was bimodally distributed and completely separated groups established on the basis of stamen number: plants referable to E. ovata had tubercles less than 0.5 mm wide and two stamens, whereas plants referable to E. obtusa had tubercles greater than 0.5 mm wide and three stamens. Since determination of stamen number requires dissection under a microscope and tubercle width requires accurate measurement, the most readily utilized character was found to be the ratio of tubercle width to achene width, which can be measured or estimated. The tubercle was less than 2/3 the width of the achene in E. ovata and more than 2/3 in E. obtusa. Differences in these characters were associated with significant but less dramatic differences in other characters, suggesting that the two taxa should be treated as distinct species. Keywords: Eleocharis obtusa, Eleocharis ovata, Cyperaceae, taxonomy, classification, Canada.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 499
Author(s):  
Vítězslav Plášek ◽  
Zuzana Komínková ◽  
Ryszard Ochyra ◽  
Lucie Fialová ◽  
Shuiliang Guo ◽  
...  

A total of 46 species and two varieties of the traditionally interpreted genus Orthotrichum are currently known to occur in China. They represent five genera, including Orthotrichum (29 species), Lewinskya (14 species and two varieties), and Nyholmiella and Leratia that are represented by a single species each. The fifth genus Florschuetziella, also consisting of only one species, F. scaberrima, is an entirely neglected representative of the China’s moss flora. A list of all accepted taxa is presented and for each taxon all literature records and herbarium specimens are enumerated for provinces in which they have been recorded, and their distribution is mapped. A key to determination of Chinese orthotrichalean mosses is presented. A chronological list of 63 species and varieties and two designations, O. catagonioides and O. microsporum which have never been validly published, reported from China in the years 1892–2020 is presented. Four species, Orthotrichum brasii, O. hooglandii, O. elegans and O. gymnostomum are excluded from the bryoflora of China and Lewinskya affinis var. bohemica and Orthotrichum schimperi are recorded for the first time from this country. Phytogeography of the Chinese taxa of the orthotrichalean mosses is considered and they are grouped into eight phytogeographical elements and five sub-elements.


2021 ◽  
Author(s):  
Sepideh Shafaei ◽  
Elyas Hosseinzadeh ◽  
Gulsah Saydan Kanberoglu ◽  
Balal Khalilzadeh ◽  
Rahim Mohammad-Rezaei

Abstract In this study, cerium oxide and multi-walled carbon nanotubes nanocomposite was incorporated into the carbon ceramic electrode (CeO2-MWCNTs/CCE) as a renewable electrode for the electrocatalytic purposes. To demonstrate capability of the fabricated electrode, determination of Tamoxifen as an important anticancer drug with differential pulse voltammetry technique was evaluated. Linear range, limit of detection and sensitivity of the developed sensor were found to be 0.2-40 nM, 0.132 nM and 1.478 µA nM-1 cm-2, respectively. Ease of production, low cost and high electron transfer rate of CeO2-MWCNTs/CCE promise it as a novel electro-analytical tool for determination of important species in real samples.


2021 ◽  
Vol 106 ◽  
pp. 392-423
Author(s):  
Ana Verónica Ortiz ◽  
Pablo Moroni ◽  
Fabiana Mirra ◽  
Rosa María Villanueva Espinoza ◽  
Nataly O'Leary

Morphological boundaries between South American species of Euphrasia L. are controversial, rendering determination of specimens an arduous task. In this context, a comprehensive taxonomic revision of Euphrasia in South America is here provided for the first time. This study, based upon a classical morphological study of ca. 400 herbarium specimens, supports the recognition of eight species and one subspecies distributed in the Andean regions of Argentina, Bolivia, and Chile. From among native species, six belong to section Trifidae Benth. and one to the monotypic section Paradoxae Pugsley, endemic to Juan Fernández Islands; one adventive species, E. officinalis L., belongs to the section Euphrasia. The previously misunderstood presence of E. cockayniana Petrie is here untangled, and, consequently, the species is excluded from South America. A key to all Euphrasia taxa in South America, plus morphological descriptions, nomenclature items, geographical distribution and maps, habitat notes, illustrations, photographs, and discussion notes are included for the nine taxa. Eleven names are here synonymized, and lectotypes are designated for E. andicola Benth., E. debilis Wettst., E. flavicans Phil., E. intricata Phil., and E. philippii Wettst. Euphrasia andicola is reported for the first time for Argentina. This collaborative effort will represent a baseline for further investigations on Euphrasia in South America.


1957 ◽  
Vol 33 (1) ◽  
pp. 25-30 ◽  
Author(s):  
D. R. Redmond

Yellow birch was once the most important species of hardwood in Eastern Canada. During the last 20 to 25 years, "birch dieback" has caused losses in the three Maritime Provinces estimated at 2,400 million cu. ft. A considerable number of species of insects feed normally on birch foliage, but none was found responsible for the disease. The bronze birch borer played a very important role in that its presence may have determined whether a tree succumbed to or recovered from decline. No fungi or bacteria found on twigs, leaves or roots were virulent enough to be considered the cause. No permanent or temporary stoppages were found in water-conducting tissues and occurrence of dieback has not been related to drought. Slight increases in soil temperature caused mortality of rootlets, which resulted in bare twigs, and small, slightly curled and chlorotic foliage. Several symptoms characteristic of virus diseases are being investigated. It is predicted that birch will form a substantial component of future forest stands, but high-grade products will be obtained only through application of intensive silviculture. Some recommended treatments are given.


Author(s):  
PK Deb ◽  
MA Rahman

The inventory and assessment of species diversity in the mono-generic family Begoniaceae C. A. Agardh of Bangladesh were made through long term field investigations, collections, identification, survey and examination of preserved herbarium specimens and review of relevant taxonomic and floristic literature. The family is recognized to be represented in the flora of Bangladesh by 19 species under the genus Begonia L. Of these, 11 species were known to be previously recorded from the area of Bangladesh, hence additional 8 species of the present account are being reported here for the first time as new records from Bangladesh, these are: Begonia grandis Dryand. ssp. holostylla Irmsch. , B. heracleifolia Cham. and Schltdl. Cult., B. maculata Raddi Cult. B. modestiflora Kurz, B. muliensis T. T. Yu. Cult., B. scintillans Dunn, B. surculigera Kurz and B. thomsonii A. DC. An enumeration of these 19 species is prepared, and each species is cited with detailed taxonomic data. All species of the Begonia L. are herbaceous in nature and possess potential economic values, viz. 11 (52%) medicinal, 5 (24%) ornamental, 3 (14%) beverage, 1 (5%) food and 1 (5%) poisonous. Determination of status of occurrence showed that 2 (10.53%) species are common, 5 (26.32%) cultivated, 9 (47.36%) threatened and 3 (15.79%) possibly extinct in Bangladesh. Field photographs and hand drawings of recorded taxa are provided.J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(1): 35-46


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