The separation of Eleocharis obtusa and Eleocharis ovata (Cyperaceae) in eastern Canada

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.


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.



2003 ◽  
Vol 81 (8) ◽  
pp. 769-779 ◽  
Author(s):  
A K Brysting ◽  
S G Aiken ◽  
L P Lefkovitch ◽  
R L Boles

Challenged by work on the Panarctic Flora project and apparent discrepancies in recent taxonomic treatments, the genus Dupontia was studied from herbarium specimens, including types and chromosome vouchers, and by numerical taxonomy, mapping the distribution of morphological characteristics, consideration of chromosome numbers, and field work in the Canadian Arctic. Our results using these techniques show random variability in many characters and differences in plant size that appear to be partly habitat related. The treatment of the genus has varied from the recognition of one variable species to three or more distinct species. Morphological characters, used in the literature to divide the genus Dupontia into more than one taxon, cannot be reliably applied to distinguish most North American plants. Continuous morphological variation in combination with high and variable ploidy levels, effective vegetative growth, and rare sexual reproduction suggests the use of a broad species concept. Until further evidence is available, our results support treating the genus as monotypic.Key words: Poaceae, Dupontia, morphology, chromosome numbers, conditional clustering, contingency tables.



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.



2014 ◽  
Vol 66 (1) ◽  
pp. 3-15
Author(s):  
Sylwia Ciaglo-Androsiuk

AbstractRelation between morphological traits of the root system and yield related traits is an important issue concerning efforts aiming at improving of ideotype of cultivated plants species, including pea. In this paper, to analyse the dependency between traits describing the root system morphology and yield potential, Person’s andSpearman's_correlations as well as canonical correlations were used.Root system was analyzed in 14 and 21 day-old seedlings growing in blotting-paper cylinders. Yield potential of pea was analysed in a field experiment. Results of Person’s and Spearman's_correlations revealed that number of lateral roots and lateral roots density were correlated witch yield related traits. Correlation between root length and shoot length was observed only for 14 day-old seedlings. The result of canonical correlations revealed that number of lateral roots and lateral roots density had the largest effect on yield related traits. This work highlights, that in order to improve the yield of pea it might become necessary to understand genetic determination of morphological traits of the root system, especially number of lateral roots.



1957 ◽  
Vol 89 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Stephen L. Wood

While investigating the biology of the North American species of Hypomolyx, field workers in Manitoba found a vestigial, or short-winged, and a long-winged form under apparently identical conditions in about equal numbers. Although biological differences were nor then apparent, there was doubt as to whether they were dealing with one dimorphic species or with two distinct species, A search for morphological characters brought to light numerous differences between the two forms, supporting the view that two species were present. These differences, a description the previously unrecognized species, and notes concerning the status of the genera Hylobius and Hypomolyx are reported below.



Phytotaxa ◽  
2021 ◽  
Vol 498 (2) ◽  
pp. 87-103
Author(s):  
YOU-PAI ZENG ◽  
QIONG YUAN ◽  
QIN-ER YANG

Based on critical observations on herbarium specimens (including type material) and living plants in the wild from its type locality, we demonstrate that Thalictrum kangdingense, recently described from Kangding county in western Sichuan province, China, is readily distinguishable from T. xinningense by an array of morphological characters but is actually conspecific with T. megalostigma, a species with its type locality also in Kangding. We therefore reduce T. kangdingense to the synonymy of T. megalostigma herein. The morphological distinction between T. baicalense and T. megalostigma is also clarified.



2021 ◽  
Vol 9 (1) ◽  
pp. 49-55
Author(s):  
Vanlal hruaia ◽  
◽  
Lal rinmuana ◽  
J Lalbiaknunga ◽  
Laldinfeli Ralte

Euphorbiaceae is one of the largest family of flowering plants, in our study different species were collected from different localities of Mizoram, the collected specimens were studied and their morphological features noted. 34 genera of Euphorbiaceae s.l were used in the study. Cladistic analysis was performed in Mesquite software and Phenetic analysis was done in NTsys software. Both analyses produce a pictorial representation in a form of a tree; cladistic analysis produce phylogenetic tree (evolutionary relationship) while phenetic analysis produce phenogram (morphological relationship). The results of the aforementioned analyses were further analysed by total evidence technique and taxonomic congruence, a phylogenetic software PAUP is used for this purpose. The resultant trees were very different and comparison was done to find correlation between evolution and morphological characters. The research finds various correlation among characters like the number of locule in ovule, phyllanthoid branching and support the inclusion of genus like Breynia, Sauropus into Phyllanthus.



Phytotaxa ◽  
2018 ◽  
Vol 367 (3) ◽  
pp. 245 ◽  
Author(s):  
TIAGO D. M. BARBOSA ◽  
RAFAELA J. TRAD ◽  
MIKLOS M. BAJAY ◽  
MARIA I. ZUCCHI ◽  
MARIA DO CARMO E. DO AMARAL

Cabomba schwartzii was described by Rataj in 1977. The species discovered in the Brazilian Amazon was said to differ from other Cabomba species in having two sepals, two petals and a lobate petal base. According to the 1991 study of Ørgaard, C. schwartzii is similar to C. aquatica in other morphological characters (C. aquatica has flowers with three sepals and three petals) and since variation in number of floral parts is common in the genus, Ørgaard synonymized both species. After an analysis of C. schwartzii type material, other herbarium collections and location of four populations (two with C. schwartzii characteristics and two with C. aquatica characteristics), we conducted an integrated morphological and genetic study to evaluate whether or not C. schwartzii is a distinct species from C. aquatica. The results reveal the species to be distinct from each other and therefore C. schwartzii should be reestablished. The floral formula for C. schwartzii is K2 C2 A2+2 G1, versus K3 C3 A3+3 G2 for C. aquatica. A detailed species description and the geographical distribution of C. schwartzii are presented with a dichotomous key to distinguish both species, together with illustrations.



2021 ◽  
Author(s):  
Ryan P. O'Donnell ◽  
Jeremy J. Bruhl ◽  
Ian R.H. Telford ◽  
Trevor C. Wilson ◽  
Heidi C. Zimmer ◽  
...  

Research into the systematics of Prostanthera has recently revealed a close evolutionary relationship among P. phylicifolia s. str., the critically endangered P. gilesii, and a population of uncertain identity from the Central Tablelands of New South Wales, Australia. Previous analyses were unable to establish whether genetic boundaries separated these taxa. This study aimed to assess the species boundaries among these three taxa using a combination of single-nucleotide polymorphisms (SNP) sampled at the population-scale and multivariate analysis of morphological characters. Non-parametric and parametric statistics, neighbour-network analysis, phylogenetic analysis, and ancestry coefficient estimates all provided support for discrete genetic differences between the three taxa. Morphological phenetic analysis identified a suite of characters that distinguished each of these taxa. This corroboration of evidence supports the presence of three independently evolving lineages. Prostanthera gilesii and P. phylicifolia s. str. are distinct species independent from the third taxon which is described here as P. volucris R.P.O'Donnell. A detailed description, diagnostic line drawings and photographs are provided. We evaluate P. volucris as satisfying criteria to be considered Critically Endangered.



Phytotaxa ◽  
2021 ◽  
Vol 502 (3) ◽  
pp. 219-229
Author(s):  
JÉRÉMIE MOREL ◽  
JÉRÔME MUNZINGER

Three endemic species of Xyris (Xyridaceae, Poales) are currently recognized in New Caledonia. A recent multivariate analysis of 18 morphological characters based on 129 specimens of Xyris from New Caledonia, supported by 10 anatomical and micromorphological observations, suggested that three species should be recognized in the New Caledonian archipelago. However, the three published names did not correspond to the three entities identified via the multivariate analyses. The results showed that Xyris neocaledonia Rendle was morphologically distinct but requires lectotypification, Xyris guillauminii Conert was indistinct from X. pancheri Rendle, and that a new morphologically distinct species required description. We therefore propose to clarify the taxonomy of the genus for New Caledonia, by designating a lectotype, making this synonymy and describing the new species. The new species, Xyris desquamatus J.R.Morel & Munzinger, sp. nov., has the remarkable feature of leaves that are shed as the plant senesces, and is reflected in the specific epithet for this new species. Line drawings are provided for the new species, along with colour photos for the three New Caledonian Xyris species and a distribution map. Three identification keys are provided, the first based on vegetative characters, the second on reproductive characters and the third on anatomical features of the leaf. Xyris desquamatus is preliminarily assigned an IUCN risk of extinction assessment of vulnerable.



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