CYTOTAXONOMY OF EUPHORBIA ESULA IN CANADA AND ITS HYBRID WITH EUPHORBIA CYPARISSIAS

1958 ◽  
Vol 36 (4) ◽  
pp. 547-559 ◽  
Author(s):  
R. J. Moore
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
The North ◽  
Artificial Hybrid ◽  
Euphorbia Cyparissias

In 14 collections of leafy spurge from Ontario and Saskatchewan the chromosome number is 2n = 60. The problem of the correct botanical name of this plant is reviewed; all the North American collections seen are classed as E. esula L. sensu lato. The morphology and cytology of an artificial hybrid, E. cyparissias × E. esula, is described; its chromosome number is 2n = 50 and meiosis is irregular. The name E. × figertii Dörfler usually applied to this hybrid is rejected in favor of the prior name E. × pseudo-esula Schur.

Cytogenetic studies of leafy spurge, Euphorbia esula, and its allies (Euphorbiaceae)

1988 ◽  
Vol 66 (11) ◽  
pp. 2247-2257 ◽  
Author(s):  
A. E. Stahevitch ◽  
C. W. Crompton ◽  
W. A. Wojtas
Keyword(s):  
Seed Germination ◽  
Chromosome Number ◽  
Natural Populations ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Meiotic Abnormalities ◽  
Stability Studies ◽  
Polymorphic Species ◽  
Cytogenetic Studies ◽  
Euphorbia Cyparissias

Cytological and cytogenetic studies were carried out on populations of leafy spurge (Euphorbia esula L. s.l.) and its allies primarily from North America but also from Europe. Chromosome numbers were determined for 126 samples of E. esula, 11 of E. cyparissias L., 1 of the hybrid (E. ×pseudoesula Schur) between these two species, and 1 of E. agraria Bieb. All plants of E. esula were hexaploid. Of the total, 125 leafy spurge accessions had a chromosome number of n = 30; 1 of n = 25++. Very few meiotic abnormalities were observed. Euphorbia cyparissias was primarily tetraploid (n = 20), although occasional diploids (n = 10) were encountered. Tetraploids were fertile; diploids were sterile. The hybrid between the two foregoing species had a chromosome number of n = 25, indicating that the E. cyparissias parent was a tetraploid; meiosis in the hybrid was abnormal. Euphorbia agraria was found to have a gametic number of n = 20, which is the first chromosome number determination for this species; meiosis was normal. Artificial crosses were made successfully between 31 accessions of leafy spurge. Seed germination of the F1 progeny slightly exceeded that reported for natural populations, and meiosis was normal. Pollen stability studies were carried out on herbarium material. Stainability was 100% for most of the samples studied. Extensive pollen size polymorphism was found. It is suggested that this phenomenon supports the hypothesis that E. esula is of allopolyploid origin. No cytological or cytogenetic basis was found for considering the leafy spurge accessions examined in this study as other than as a single, albeit somewhat polymorphic, species.

Morphometric studies of the Euphorbia esula group (Euphorbiaceae) in North America

1990 ◽  
Vol 68 (9) ◽  
pp. 1978-1988 ◽  
Author(s):  
C. W. Crompton ◽  
A. E. Stahevitch ◽  
W. A. Wojtas
Keyword(s):  
North America ◽  
Morphological Characters ◽  
Leafy Spurge ◽  
Principal Coordinate Analysis ◽  
Euphorbia Esula ◽  
Eastern North America ◽  
Single Variable ◽  
Authentic Material ◽  
Variable Species ◽  
Euphorbia Cyparissias

Leafy spurge and cypress spurge are important weeds of pastures and unimproved rangeland in western and eastern North America, respectively. Taxonomists disagree as to whether leafy spurge is a single variable species or an aggregate of two or more species. Morphometric techniques (clustering by incremental sum of squares and principal coordinate analysis) were used to analyze relationships in leafy spurge and its allies. On the basis of studying 26 morphological characters found in 200 collections representing 32 putative taxa, we concluded that in North America only four species should be recognized, namely, Euphorbia agraria Bieb., Euphorbia cyparissias L., Euphorbia esula L., and Euphorbia ×pseudoesula Schur. A key to these taxa is provided. No authentic material of Euphorbia lucida Waldst. & Kitt. and Euphorbia salicifolia Host was found from this continent in the collections we examined.

Taxonomy of the Carex flava complex (Cyperaceae) in North America and northern Eurasia. II. Taxonomic treatment

1989 ◽  
Vol 67 (4) ◽  
pp. 1048-1065 ◽  
Author(s):  
William J. Crins ◽  
Peter W. Ball
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Northern Eurasia ◽  
Distribution Maps ◽  
Taxonomic Treatment ◽  
The North ◽  
Infraspecific Taxa ◽  
History Of ◽  
Inflorescence Structure

The taxonomy of the Carex flava complex (section Ceratocystis) in North America and northern Eurasia is revised. Three species are recognized in this complex (C. flava L., C. cryptolepis Mack., and C. viridula Michx.). Carex viridula contains six infraspecific taxa, which are differentiated on the basis of differences in inflorescence structure, degree of perigynium curvature, leaf and bract morphology, chromosome number, and ecological preference. Three nomenclatural changes are required: C. viridula ssp. brachyrrhyncha (Čelak.) B. Schmid var. elatior (Schlecht.) Crins, comb.nov.; C. viridula ssp. brachyrrhyncha var. nevadensis (Boiss. & Reuter) Crins, comb.nov.; C. viridula ssp. brachyrrhyncha var. saxilittoralis (Robertson) Crins, comb, et stat.nov. This classification reflects the results of morphological, ecological, and cytological studies, and is also consistent with the hypothesized phylogenetic history of the section as a whole. A key is provided for all of the North American and northern Eurasian members of section Ceratocystis. Descriptions and distribution maps for members of the C. flava complex are also provided.

BASIC CHROMOSOME NUMBER, CYANOGENETIC GLUCOSIDE VARIATION, AND GEOGRAPHIC DISTRIBUTION OF LOTUS SPECIES

1967 ◽  
Vol 45 (5) ◽  
pp. 639-647 ◽  
Author(s):  
William F. Grant ◽  
B. S. Sidhu
Keyword(s):  
Chromosome Number ◽  
Geographic Distribution ◽  
North American ◽  
New World ◽  
Basic Chromosome Number ◽  
North American Species ◽  
Hydrocyanic Acid ◽  
Basic Chromosome ◽  
Fresh Leaf ◽  
The North

Leaves of 51 species and three varieties of Lotus (Leguminosae) were assessed quantitatively for hydrocyanic acid (HCN) reaction intensity and the data correlated with basic chromosome number and geographic distribution. The presence of HCN was determined from 0.05 grams of fresh leaf samples by the picric acid – filter paper technique. A gradation of 10 different color reactions (−), (±), and (+1 to +8) was used to compare the HCN reaction for each species. On the basis of potassium cyanide equivalents, each gram of fresh leaf material was estimated to contain an amount of HCN which varied between the different plants and accessions from 0.5 mg to 750 mg. Most of the Old World species were positive for HCN, whereas the reverse was true for the North American species. This would favor the previous separation of the North American species into a separate genus Hosackia. All of the n = 7 species have a greater concentration of HCN than the n = 6 species in both the Old and New World. None of the n = 6 species in the New World reacted positively. Therefore, there was a reduction of HCN with evolutionary development. Two colchicine-induced tetraploids (4x = 24, 28) gave a lower HCN reaction than their diploid counterparts. Leaves of L. siliquosus (n = 7) reacted negatively to the HCN test; however, the cotyledons gave a highly positive reaction supporting the retention of the generic name Tetragonolobus (T. siliquosus (L.) Roth.) for this species. Chromosome number determinations are reported for the first time for L. holosericeus Webb and Berth. (2n = 14), L. mascaensis Buchard (2n = 28), L. nevadensis Greene (2n = 14), L. helleri Britton (2n = 14), and L. oblongifolius var. nevadensis (Gray) Munz (2n = 14).

scholarly journals Genetic variation in North American leafy spurge (Euphorbia esula) determined by DNA markers

Weed Science ◽  
1997 ◽  
Vol 45 (3) ◽  
pp. 446-454 ◽  
Author(s):  
Martha L. Rowe ◽  
Donald J. Lee ◽  
Scott J. Nissen ◽  
Brunella M. Bowditch ◽  
Robert A. Masters
Keyword(s):  
Genetic Variation ◽  
North American ◽  
Rapd Markers ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Range Of Movement ◽  
Multiple Introductions ◽  
Cpdna Markers ◽  
Intrapopulation Genetic Variation ◽  
High Degree

Levels of inter- and intrapopulation genetic variation were determined in five North American populations of leafy spurge using chloroplast DNA (cpDNA) RFLPs and RAPD markers. Thirteen plastome types were identified among 123 individuals collected from five geographically separated populations. Number of plastomes within a population ranged from one to seven, with four of the populations having a predominate type plus one or more rarer types. Some plastome types were shared by populations, but plastome distribution among populations was nonrandom. RAPD markers indicated greatest relatedness among individuals within a population. Relatedness among populations as established through RAPDs was greater for geographically closer populations; this relationship was not observed for cpDNA markers. Differences in the range of movement for pollen and seed may account for differences between results of the cpDNA and RAPD analyses. The high degree of genetic variability among North American leafy spurge suggests possible multiple introductions or a high degree of variability within leafy spurge populations in its native range.

TAXONOMICAL VALUE OF ALISMA TRIVIALE PURSH AND ALISMA SUBCORDATUM RAFIN

1963 ◽  
Vol 41 (7) ◽  
pp. 1011-1013 ◽  
Author(s):  
Eugenia Pogan
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Morphological Characters ◽  
The North

Detailed morphological and karyological studies have revealed that the North American taxa of the Alisma plantago-aquatica complex are most appropriately classified as the two species, A. subcordatum Rafin. (2n = 14), and A. triviale Pursh (2n = 28). The morphological characters separating these species and distinguishing them from the European diploid, A. plantago-aquatica L., s. str., are given, and also the chromosome number of American material of A. gram-ineum Gmel. (2n = 14).

Mitotic analysis of the North American white sturgeon, Acipenser transmontanus Richardson (Pisces, Acipenseridae), a fish with a very high chromosome number

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 266-271 ◽  
Author(s):  
A L Eenennaam ◽  
J D Murray ◽  
J F Medrano
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Sex Chromosome ◽  
Chromosomal Polymorphism ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Banding Technique ◽  
Supernumerary Chromosomes ◽  
C Banding ◽  
The North

The average chromosome number of the North American white sturgeon, Acipenser transmontanus Richardson, was found to be 271 ± 2.5 (ranging from 265 to 276). This number is significantly higher than previous estimates for this species. A representative karyotype was found to consist of 132 meta- and submeta-centric chromosomes, 44 acrocentric chromosomes, and 98 microchromosomes. An improved C-banding technique revealed variation (2-7) between animals in the number of entirely heterochromatic metacentric chromosomes. These heterochromatic chromosomes may represent supernumerary chromosomes. There was no cytogenetic evidence of a heteromorphic sex chromosome pair or any sex-related chromosomal polymorphism in either sex of this species.Key words: C-banding, fish, karyotype, supernumerary chromosomes, white sturgeon.

Sign in / Sign up

Export Citation Format

Share Document