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.

scholarly journals Release of Postsenescent Dormancy in Leafy Spurge (Euphorbia esula) by Chilling

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 784-786 ◽  
Author(s):  
Stephen J. Harvey ◽  
Robert M. Nowierski
Keyword(s):  
Growth Rate ◽  
North America ◽  
Growth And Development ◽  
Leafy Spurge ◽  
Climatic Conditions ◽  
Euphorbia Esula ◽  
Flower Buds ◽  
Significant Growth ◽  
Number Of Stems

The growth and development of leafy spurge (Euphorbia esulaL. #3EPHES) collected during postsenescent dormancy and grown in the greenhouse was increasingly stimulated by chilling treatments longer than 14 days duration at 0 to 6 C. Production of stems with flower buds, primary flowers, and secondary flowers was greater in plants chilled for 42 days or more. The effects of chilling on total number of stems, number of strictly vegetative stems, or number of stems with vegetative branching were not significant. The height of the tallest stem per pot was influenced by chilling longer than 42 days. Growth rate also increased as a function of chilling duration. Based on our findings, we believe that there is little possibility that any significant growth can occur in the postsenescent period because of the prevailing climatic conditions found in areas of leafy spurge distribution in North America.

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.

scholarly journals Slender Moonwort, Botrychium lineare (Ophioglossaceae), Rediscovered in Quebec

2009 ◽  
Vol 123 (3) ◽  
pp. 255 ◽  
Author(s):  
Jacques Cayouette ◽  
Donald R. Farrar
Keyword(s):  
North America ◽  
Plant Species ◽  
Morphological Characters ◽  
Ongoing Study ◽  
Eastern North America ◽  
Allozyme Electrophoresis ◽  
Spore Size ◽  
Habitat Features ◽  
Gaspe Peninsula ◽  
Made In

Slender Moonwort (Botrychium lineare), described in 1994, is a very rare fern in eastern North America. It was known in Quebec, Canada, from only two sites in the Gaspé Peninsula but has not been relocated since its discovery at these sites in 1902 and 1942. An ongoing study of B. lineare and its recent discovery in northern Minnesota prompted a re-examination of a 1972 collection made in western Quebec, in Gatineau Park, previously identified under various names, including B. campestre. A recent visit (2008) to the Gatineau Park site disclosed continued presence of similar plants. Based on morphological characters, spore size, genotype (allozyme electrophoresis), and appropriate habitat features, we conclude that the newly discovered plants and those of the 1972 collection are B. lineare. B. lineare appears on the Quebec government list of plant species likely to be designated threatened or vulnerable.

Euphorbia esula (L.), leafy spurge, and Euphorbia cyparissias (L.), cypress spurge (Euphorbiaceae).

2009 ◽  
pp. 346-358 ◽  
Author(s):  
R. S. Bourchier ◽  
S. Erb ◽  
A. S. McClay ◽  
A. Gassmann
Keyword(s):  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Euphorbia Cyparissias

Generic relationships within Leonticeae (Berberidaceae)

1989 ◽  
Vol 67 (8) ◽  
pp. 2310-2316 ◽  
Author(s):  
Henry Loconte ◽  
James R. Estes
Keyword(s):  
North America ◽  
Morphological Characters ◽  
Eastern North America ◽  
Eastern Asia ◽  
Operational Taxonomic Units ◽  
Generic Relationships

Phenetic analyses of morphological characters of Leonticeae reveal three distinct groups of operational taxonomic units corresponding to genera. The genera Leontice and Gymnospermium of Eurasia are pheneticlly equidistant from Caulophyllum, which occurs in eastern Asia and eastern North America. On the basis of phenetic similarity, L. kiangnanensis is transferred to Gymnospermium as G. kiangnanensis.

Species of Cortinarius subgenus Leprocybe, sections Orellani and Limonei, in North America

1994 ◽  
Vol 72 (4) ◽  
pp. 520-532 ◽  
Author(s):  
R. G. Thorn ◽  
D. W. Malloch
Keyword(s):  
North America ◽  
Morphological Characters ◽  
The Other ◽  
Mushroom Poisoning ◽  
Eastern North America ◽  
Similar Species ◽  
Western North America ◽  
Genetic Studies ◽  
Rdna Sequences ◽  
Fluorescent Compounds

Descriptions and a key are provided to seven species of Cortinarius subg. Leprocybe, sect. Orellani and Limonei, that are found in North America, namely C. callisteus (synonym C. croceocolor), C. distans var. olympianus, C. gentilis (synonym C. confusus), C. limoneus (synonym C. whiteae), C. morrisii, C. rainierensis, and C. speciosissimus. Of these, C. rainierensis and C. speciosissimus were previously shown to contain the nephrotoxin orellanine. Reports of C. orellanus from North America were based on misidentifications of C. uliginosus or similar species of subg. Dermocybe. There are no apparent morphological features to distinguish C. speciosissimus, which has been found in eastern North America, from C. rainierensis, which is known only from the state of Washington in western North America, or from C. orellanoides, which was described from France. Since morphological characters were found for the distinction of sibling species discovered by biochemical and genetic studies in other genera, including Armillaria, we prefer not to accept or suggest the synonymy of these taxa until neotypes or lectotypes are selected for C. croceocolor and C. rubellus and these specimens are compared with types of the other available names using chromatography of fluorescent compounds or rDNA sequences. Key words: biosystematics, mushroom poisoning, orellanine.

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