The Galium aparine complex in Canada

Abstract

The occurrence in Canada of Galium aparine sensu lato has been studied. It is concluded that two species are present: G. aparine L. sensu stricto (Cleavers) and G. spurium L. (False Cleavers). Although closely related and morphologically similar, these species differ morphologically, cytologically, and physiologically. The chromosome number of collections of G. aparine from Canada and the United States was found to be 2n = 66, that of G. spurium from the prairie provinces of Canada was 2n = 20. The latter species is an introduction from Eurasia and seems to be the more serious weed in fields of grain and rapeseed in western Canada. Galium aparine is believed to be native, as well as introduced from Eurasia, in North America. Galium aparine occurs usually in moist, shaded habitats, whereas G. spurium favors sunnier habitats. Both species have spiny or smooth fruits and these fruit variants have been recognized at various taxonomic levels. In this paper they are reduced to the rank of form.

THE BIOLOGY OF CANADIAN WEEDS.: 86. Galium aparine L. and Galium spurium L.

“…G. aparine is based on those by Moore (1975), Holm et al (1977), Korsmo et al (1981) and Hanf (1983). Two forms of G. spurium have been recognized in Canada: l. Galium spurium forma spuriunr, fruits smooth (Fig.…”

“…2d). Moore (1975) Moore (1975) 3. Economic Importance (a) Detrimental-Galium aparine has been reported to compete effectively with cereals, rapeseed and sugarbeet.…”

“…In Canada (Fig. 5 (Moore 1975 (Dew 1982), Moore (1975), Scoggan (1979), Taylor andMulligan (1968), Thomas and Wise (1982, 1986, CanadaWeed Survey Frankton 1946, 1948) For personal use only. of germination is observed in February or in…”

Effect of Aqueous Extracts of Sticky Willy (Galium aparine L.) on the Growth of Seedlings of Selected Maize Varieties (Zea mays L.)

“…(Goodman, 2005;Bauer et al, 2011;Hayley and Badyal, 2014). G. aparine usually produces 100 to 400 seeds with hooked hairs that facilitate the dispersion of seeds by animals (zoochory) (Moore, 2011). The vitality of seeds in soil lasts for up to three years; the seeds germinate both in shade and in full sunlight, on fertile clay soils with a pH value between 5.5 and 8.0, and where the content of nitrogen and phosphorus is high (Taylor, 1999).…”

The biology of Canadian weeds. 121. Galium mollugo L.

“…The most obvious differences between these two species are their fruit size, flower size, and flower colour. Galium aparine flowers are larger (2 mm in diameter) and white, whereas flowers of G. spurium are 1.0-1.5 mm in diameter and greenish-yellow in colour (Moore 1975). The fruit of G. aparine is typically 2.8-4.0 mm long, but fruits of G. spurium are 1.5-2.8 mm long (Moss 1983).…”