The biology of Canadian weeds. 113. Symphyotrichum lanceolatum (Willd.) Nesom [Aster lanceolatus Willd.] and S. lateriflorum (L.) Löve & Löve [Aster lateriflorus (L.) Britt.]

Abstract

Symphyotrichum lanceolatum, the tall white aster, is a morphologically variable, native North American, polyploid (tetraploid, pentaploid, hexaploid, heptaploid, and octoploid cytotypes) species with a transcontinental distribution. Commonly found along fence rows, ditches, road and rail right-of-ways, and field, pond, and wood lot margins, the species is not a serious agricultural weed but may become problematic in neglected fields, poorly managed pastures, and cultivated fields on recently plowed land. For this review of the biology of the species, we recognize two subspecies, the eastern subsp. lanceolatum and western subsp. hesperium. The former is further divided into varieties lanceolatum, hirsuticaule, interior, and latifolium. Symphyotrichum lateriflorum, the one-sided aster, is also morphologically variable. The distribution of this native, polyploid (diploid, tetraploid, hexaploid, and octoploid cytotypes) extends from the Magdalen Islands and Prince Edward Island in the north, south to Florida, Mississippi, Louisiana, and Texas. Occurring in a variety of habitats, including dry to wet thickets, open woods, shorelines, mesic to wet-mesic prairies, and dry open places, the species is possibly the least weedy of the weedy asters in Canada, but nonetheless may become problematic in neglected fields, poorly managed pastures, or roadside right-of-ways. Although several varieties have been described, little agreement surrounds their recognition, as characters considered useful by some are designated useless by others. This contribution summarizes the known biological data for the two species. For personal use only.

The Potential Use of Agroforestry Community Gardens as a Sustainable Import-Substitution Strategy for Enhancing Food Security in Subarctic Ontario, Canada

“…Being tolerant of a wide variety of soil types and environmental conditions, including high moisture soils, most of these species are highly competitive, with the exception of panicled aster, which is moderately competitive [42][43][44][45][46]. Hemp nettle, wormseed and Canada thistle are non-native and known to be -weedy‖ or invasive competitors to crops [42][43][44][45][46]. Creeping bentgrass, has been naturalized in North America since 1750 and used as important forage for livestock; it has become -weedy‖ or invasive in some areas and can often be found with willows as the dominant overstory [45,46].…”

“…The grasses and forbs that dominated the old agricultural fields, Galeopsis tetrahit (hemp nettle), Artemisia cina (wormseed), Cirsium arvense (Canada thistle), Symphyotrichum lanceolatum (panicled aster), and Agrostis Stolinifera (creeping bentgrass) (Table 1), are all pioneer species commonly found on recently exposed sites, such as roadsides, wastelands and cultivated fields as well as the shores of water bodies [42][43][44][45][46]. Being tolerant of a wide variety of soil types and environmental conditions, including high moisture soils, most of these species are highly competitive, with the exception of panicled aster, which is moderately competitive [42][43][44][45][46].…”

“…Being tolerant of a wide variety of soil types and environmental conditions, including high moisture soils, most of these species are highly competitive, with the exception of panicled aster, which is moderately competitive [42][43][44][45][46]. Hemp nettle, wormseed and Canada thistle are non-native and known to be -weedy‖ or invasive competitors to crops [42][43][44][45][46].…”

Factors Affecting Seed Germination of the Invasive Species Symphyotrichum lanceolatum and Their Implication for Invasion Success

“…The species is native to North America and Canada, and invasive in many European countries [ 30 ]. S. lanceolatum blooms and bears fruits in late summer to late autumn and aboveground parts die back subsequently [ 31 , 32 ]. Achenes mature 3 to 4 weeks after pollination, and new seedlings occur in spring [ 31 ].…”

Allelopathic potential of the invasive species Aster lanceolatus Willd.

“…However, mechanisms that allow A. lanceolatus to be so competitive and to become dominant in riverine plant communities are not clear. Several potentially allelopathic compounds have been identified in A. lanceolatus tissues (15) and it is possible that those substances could contribute to the rapid spread of this species. The objective of this research is to determine the allelopathic potential of aqueous extracts of fresh and dry biomass of Aster lanceolatus Willd.…”