Cytogeographical Studies in the Genus Arnica (Compositae: Senecioneae). I.

Origins and Widespread Distribution of Co-existing Polyploids in Arnica cordifolia (Asteraceae)

“…This work not only helps elucidate the relationship between cytotypes, but it also suggests that these are distinct lineages. Contrary to previous theories as to the origins of cytotypes in A. cordifolia (Wolf, 1987), this work supports the creation of tetraploids and pentaploids from triploids. A more broad-scale survey of samples from throughout the range of A. cordifolia, instead of just the edges of its range, will help clarify the molecular relationships among ploidies and the distribution of molecular diversity within this species.…”

“…One explanation for the origin of these three cytotypes is the creation of triploids from diploids, with subsequent cross-matings creating tetraploids and pentaploids. This would mean that diploids were once widespread (as thought previously by Wolf, 1980) but are now either rare or extinct since they were not found in this study. Asexual species having a broader distribution than their sexual counterparts is a common phenomenon (Bierzychudek, 1985).…”

Origins and Widespread Distribution of Co-existing Polyploids in Arnica cordifolia (Asteraceae)

“…This work not only helps elucidate the relationship between cytotypes, but it also suggests that these are distinct lineages. Contrary to previous theories as to the origins of cytotypes in A. cordifolia (Wolf, 1987), this work supports the creation of tetraploids and pentaploids from triploids. A more broad-scale survey of samples from throughout the range of A. cordifolia, instead of just the edges of its range, will help clarify the molecular relationships among ploidies and the distribution of molecular diversity within this species.…”

“…One explanation for the origin of these three cytotypes is the creation of triploids from diploids, with subsequent cross-matings creating tetraploids and pentaploids. This would mean that diploids were once widespread (as thought previously by Wolf, 1980) but are now either rare or extinct since they were not found in this study. Asexual species having a broader distribution than their sexual counterparts is a common phenomenon (Bierzychudek, 1985).…”

Morphological, cytological, and flavonoid variability of the Arnica angustifolia aggregate (Asteraceae)

“…tomentosa. Engell (1970) and Wolf (1980 Locality and voucher tomentosa are in agreement with those previously published by ploid and tetraploid individuals are widely scattered through- Love and Love (1975), Straley (1979), and Wolf (1980). No out previously glaciated areas.…”

Mexican species of the genus Stevia (Eupatorieae, Asteraceae): Chromosome numbers and geographical distribution

“…The widespread distribution of agamospermous polyploids compared with the restricted range of their diploid ancestors has been noted in various taxonomic groups (Babcock & Stebbins 1938; Gustaffson 1947; Müntzing 1954; Stebbins 1971; Sullivan 1976; Grant 1981; Watanabe 1986). Bayer and Stebbins (1981, 1983) and Wolf (1980) explained this distributional pattern (which was confirmed in the genera Antennaria and Arnica growing in areas severely affected by successive advances and recessions of Pleistocene ice sheets) in the following way. The ancestral diploids were probably restricted to small southern areas at the end of the last glaciation.…”

Origins and Widespread Distribution of Co-existing Polyploids in Arnica cordifolia (Asteraceae)

“…This work not only helps elucidate the relationship between cytotypes, but it also suggests that these are distinct lineages. Contrary to previous theories as to the origins of cytotypes in A. cordifolia (Wolf, 1987), this work supports the creation of tetraploids and pentaploids from triploids. A more broad-scale survey of samples from throughout the range of A. cordifolia, instead of just the edges of its range, will help clarify the molecular relationships among ploidies and the distribution of molecular diversity within this species.…”

“…One explanation for the origin of these three cytotypes is the creation of triploids from diploids, with subsequent cross-matings creating tetraploids and pentaploids. This would mean that diploids were once widespread (as thought previously by Wolf, 1980) but are now either rare or extinct since they were not found in this study. Asexual species having a broader distribution than their sexual counterparts is a common phenomenon (Bierzychudek, 1985).…”

Morphological, cytological, and flavonoid variability of the Arnica angustifolia aggregate (Asteraceae)

“…tomentosa. Engell (1970) and Wolf (1980 Locality and voucher tomentosa are in agreement with those previously published by ploid and tetraploid individuals are widely scattered through- Love and Love (1975), Straley (1979), and Wolf (1980). No out previously glaciated areas.…”

Mexican species of the genus Stevia (Eupatorieae, Asteraceae): Chromosome numbers and geographical distribution

“…The widespread distribution of agamospermous polyploids compared with the restricted range of their diploid ancestors has been noted in various taxonomic groups (Babcock & Stebbins 1938; Gustaffson 1947; Müntzing 1954; Stebbins 1971; Sullivan 1976; Grant 1981; Watanabe 1986). Bayer and Stebbins (1981, 1983) and Wolf (1980) explained this distributional pattern (which was confirmed in the genera Antennaria and Arnica growing in areas severely affected by successive advances and recessions of Pleistocene ice sheets) in the following way. The ancestral diploids were probably restricted to small southern areas at the end of the last glaciation.…”

Origins and Widespread Distribution of Co-existing Polyploids in Arnica cordifolia (Asteraceae)

“…This work not only helps elucidate the relationship between cytotypes, but it also suggests that these are distinct lineages. Contrary to previous theories as to the origins of cytotypes in A. cordifolia (Wolf, 1987), this work supports the creation of tetraploids and pentaploids from triploids. A more broad-scale survey of samples from throughout the range of A. cordifolia, instead of just the edges of its range, will help clarify the molecular relationships among ploidies and the distribution of molecular diversity within this species.…”

“…One explanation for the origin of these three cytotypes is the creation of triploids from diploids, with subsequent cross-matings creating tetraploids and pentaploids. This would mean that diploids were once widespread (as thought previously by Wolf, 1980) but are now either rare or extinct since they were not found in this study. Asexual species having a broader distribution than their sexual counterparts is a common phenomenon (Bierzychudek, 1985).…”

Morphological, cytological, and flavonoid variability of the Arnica angustifolia aggregate (Asteraceae)

“…tomentosa. Engell (1970) and Wolf (1980 Locality and voucher tomentosa are in agreement with those previously published by ploid and tetraploid individuals are widely scattered through- Love and Love (1975), Straley (1979), and Wolf (1980). No out previously glaciated areas.…”

Mexican species of the genus Stevia (Eupatorieae, Asteraceae): Chromosome numbers and geographical distribution

“…The widespread distribution of agamospermous polyploids compared with the restricted range of their diploid ancestors has been noted in various taxonomic groups (Babcock & Stebbins 1938; Gustaffson 1947; Müntzing 1954; Stebbins 1971; Sullivan 1976; Grant 1981; Watanabe 1986). Bayer and Stebbins (1981, 1983) and Wolf (1980) explained this distributional pattern (which was confirmed in the genera Antennaria and Arnica growing in areas severely affected by successive advances and recessions of Pleistocene ice sheets) in the following way. The ancestral diploids were probably restricted to small southern areas at the end of the last glaciation.…”