S.nemoralis is absent in European vegetation, but considering its characteristics (high seed production, rapid seed spread and vegetative spread), which are very similar to the naturalized invasives Solidago canadensis and ...
S.nemoralis is absent in European vegetation, but considering its characteristics (high seed production, rapid seed spread and vegetative spread), which are very similar to the naturalized invasives Solidago canadensis and Solidago gigantea, this species can be considered as a potential invasive species (EPPO, 2009). The Plant Collections Network of Britain and Ireland developed a database on invasive and potentially invasive alien plants in European Botanic Gardens. The freely available data base comprises 32 European national lists with 622 species. According to this database S. nemoralis has not yet occurred in European botanical gardens.
In Switzerland the handling of alien plants and animals is regulated to stop the displacement of indigenous species. The Swiss list S. nemoralis as a potential invasive species (DETEC, 2009).
Solidago nemoralis was described and published in Hort. Kew. (3: 213) in 1789 by William Aiton. Two intraspecific variations were determined – Solidago nemoralis Aiton ssp. nemoralis and Solidago nemoralis ssp. decemflora (DC.) Brammall (Semple, 1985; Chmielewski and Semple, 2004).
S. nemoralis is a polycarpic hemi-cryptophyte (Walck et al., 1997a), that reproduces vegetatively from branched caudices (short, thick, vertical underground stems) (Gibson, 1961). Stems are erect from the short-branched caudex, 20-100 cm tall, are solitary to many (2-10), and densely covered by short, ascending, appressed hairs. Basal rosette and lower stem leaves are 2.0-9.5 cm long, 0.7-1.5 cm wide, spathulate-ovate to oblanceolate, acute, tapering to a long winged petiole. Leaf margins are entire or with rounded teeth. Both leaf surfaces are densely covered in minute, fine, short hairs. Upper stem leaves are reduced upwards, 1.6-4.5 cm long, 0.3-0.7 cm wide, becoming linear-oblanceolate, sessile, entire sometimes subtending axillary tufts of lateral branch leaves, with both surfaces densely covered in minute, fine, short hairs. The inflorescence is paniculiform, wand-shaped pyramidal, secund (on one side of the stem or branch, leaning to one side) to apically recurved, sometimes the lower inflorescence branches are elongated and repeating the pattern.
Peduncles are 2.0-3.5 mm long. The flowering heads are 2.6-5.8 mm high. The phyllaries (head bracts) are arranged in several unequal series, number 22-30, are ovate to linear-lanceolate, the innermost acute, the outermost obtuse. Rays number 5-11, are 2.8-5.5 mm long, 0.3-0.7 mm wide, and yellow. The ray pappus measures 1.5-3.6 mm long. Disc florets number 3-10, are 2.5-4.6 mm long, the lobes 0.4-0.6 mm long. The disc pappus measures 2.0-4.0 mm. The achenes are covered in straight, stiff, appressed hairs, those of the disc florets 0.5-2.0 mm long.
S. nemoralis is morphologically variable throughout its range and includes eastern S. nemoralis ssp. nemoralis and western North American S. nemoralis ssp. decemflora (DC.) Brammall races (Semple, 1985; Semple et al., 1990). The eastern race is commonly diploid, though tetraploids do occur in scattered locations. The western race is strictly tetraploid.
In S. nemoralis ssp. nemoralis the pappus bristles generally do not, or barely exceed the ray floret corolla tube and the base of the disc floret lobes; disc corolla lobes are 0.5-0.9(1.0) mm long; the flowering heads are mostly less than 4.2 mm high, but tetraploids do have larger flowering heads; mature achenes are usually only sparsely covered with stiff, sharp, appressed hairs; and the basal leaves are usually with rounded teeth about the margins.
In S. nemoralis spp. decemflora the pappus bristles generally do exceed the ray floret corolla tube and the base of the disc corolla lobes; disc corolla lobes are (0.6)0.8-1.5 mm long; the flowering heads are mostly greater than 4.6 mm high; mature achenes are moderately covered with stiff, sharp, appressed hairs; basal leaves are usually not with rounded teeth about the margins (Semple et al., 1990; Chmielewski and Semple, 2004). A third race, southern in distribution (var. haleana), is described as having an inflorescence branching that is more open and elm-like than considered typical. Because insect damage may alter the appearance of an inflorescence, and not all shoots of an individual plant may have the same inflorescence trait, margins Semple et al. (1990) chose to treat the third race as a form rather than a subspecies (Chmielewski and Semple, 2004).
S. nemoralis is native to North America (Walck et al., 1997a). It occurs from Nova Scotia in the northeast, westward to British Columbia and southward to Florida and Texas (Scoggan, 1979). S. nemoralis ssp. nemoralis occurs throughout the eastern deciduous forest region of North America (i.e. Appalachian and Atlantic-Gulf Coastal Plain Floristic Provinces (Cronquist, 1982). S. nemoralis ssp. decemflora typically occurs on the prairies (North American Prairies Floristic Province (Cronquist, 1982)) and sometimes at elevations of the Rocky Mountains from New Mexico to British Columbia (Semple et al., 1990). S. nemoralis ssp. decemflora is rare in Ontario and British Columbia and threatened in Colorado (Brunton and Semple, 1987; Chmielewski and Semple, 2004).
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
As it is similar to other invasive Solidago species in Europe and other parts of the world, S. nemoralis can be considered as a potential invasive species in natural and semi-natural environments. It is advertised for landscaping purposes in Europe, and hence was added to the EPPO Watch List in 2004 to 2012, after which it was transferred to the Observation List.
In actuality, S. nemoralis flowered in the study plot during the second year and occurred in quadrate vegetation in year 4 though it did not appear in the seed bank until year 5, and then persisted to the end of the study in year 10 (Leck and Leck, 1998). Dormancy is broken by cold stratification in late autumn/winter and by early spring the seeds are non-dormant. Those seeds that not do germinate during the first spring following dispersal may re-enter conditional dormancy in the late spring/winter period (Walck et al., 1997b). At least three consecutive days of soil moisture are necessary for S. nemoralis to germinate with any regularity (Walck et al., 1997b). S. nemoralis may reproduce vegetatively from a short-branched caudex (Havercamp and Whitney, 1983, Semple et al., 1999). Reproduction is almost entirely by seeds (Werner, 1976).
Physiology and Phenology
S. nemoralis is a short-day plant that requires vernalization for flowering to occur (Walck et al., 1999). Flowering occurs from late June to December in North America (Fernald, 1950; Semple et al., 1990, 1999; Chmielewski and Semple, 2004). Similarly, blooming occurred approximately between days 230 and 270 (essentially mid-August until the end of September) in a Wisconsin prairie site (Anderson and Schelfhout, 1980). Ramet variation in flowering phenology (duration and initiation of) was described in detail by Gross and Werner (1983). According to their studies flowering phenology was nearly synchronous with that of S. canadensis, but peak bloom occurred approximately 7-10 days later than for Euthamia graminifolia.
Germination typically occurs in early spring. In New Jersey, seeds germinated in April, May or September, but none germinated in mid-summer (Beimborn, 1970, 1973). Seeds that do not germinate during the first spring following dispersal (during the previous autumn) may re-enter conditional dormancy in late spring/summer, and then during the second late autumn/winter period become non-dormant (Walck et al., 1997b). Seeds of the geographically–widespread Solidago altissima and S. nemoralis and the narrow-spread endemic S. shortii were buried in pots of soil and placed in a glasshouse without temperature control. After 0.3-4.3 years of burial, some seeds (21-60%) of all three species were viable and they germinated to 75-100% during incubation in light (Walck et al., 1998).
S. nemoralis occurs in prairie-like open fields, oak savannahs, along roadsides, woods, and disturbed ground in southwestern Ontario (Semple et al., 1999). The species is also known to occupy chalk outcrops, rock outcrops, pastures, and riparian habitats (Walck et al., 1997a; Leidolf et al., 2002). Less frequently colonized habitats by S. nemoralis include shale barrens, ravines, uplands, and disturbed sites (Chmielewski and Semple, 2004).
Little is known of the specific climatic requirements of S. nemoralis although the North American distribution of the species would suggest that is adapted to a wide range of environmental and physiographic conditions. Light tolerances range between full to light shade (Chmielewski and Semple, 2004).
In central Ontario the species was reported from dry, sparsely vegetated and barren areas that were acidic (pH 5.5) and low in calcium (500 ppm) and from prairie openings which had 0.1-0.25 m of dark-brown humus rich sand (pH of 6.6-7.4 and calcium levels from 1600-3300 ppm).
S. nemoralis is weedy in Canada and the United States (Darbyshire et al., 2000; Chmielewski and Semple, 2004). A nuisance value (derived from sites occupied and abundance) of 125 was reported for the species from populations sampled in Ontario, Québec, and Maine (Dale et al., 1965). Various species of goldenrod, including S. nemoralis, possess similar medicinal properties when used in conjunction with appropriate antibiotics. S. nemoralis is a source of nectar for adult butterflies and honeybees (Chmielewski and Semple, 2004).
Large-scale infested areas of S. nemoralis are a result of the inappropriate management of grasslands and old fields. S. nemoralis competes with native flora and vertebrate fauna, reducing grass and other low-growing plants. Monodominated communities cause a decrease in field diversity.
S. nemoralis ssp. decemflora may be similar to the subspecies S. velutina ssp. californica and S. velutina ssp. sparsiflora. S. nemoralis differs form S. velutina in that S. nemoralis has short rhizomes, whereas S. velutina possesses creeping rhizomes (Chmielewski and Semple, 2004). S. nemoralis is shorter than S. canadensis, S. gigantea and S. altissima, which are generally up to 5 ft tall while S. nemoralis is usually less than 3 ft tall. S. gigantea has smooth (hairless) stems below the inflorescence. S. canadensis has hairy stems below the inflorescence but the hairs diminish and disappear further down the stem.
S. speciosa and S. nemaralis have leaves that are largest at the bottom and are progressively smaller moving up the stem. Beneath the inflorescence, S. speciosa is smooth stemmed while S. nemoralis has pubescent stems.
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Repeated mowing for at least 2 years effectively controlled S. nemoralis on Missouri pasture land. Further, the timing of mowing had little effect on the degree of control. Although annual mowing, early in the season, for two consecutive years also significantly reduced stands of S. nemoralis, this control method was not as consistently effective as was repeated mowing (Peters and Lowance, 1978). Based on field studies conducted in open (pioneered by annual species and short-lived perennials) and closed (90-100% cover of perennial pasture plants) communities in Québec, S. nemoralis demonstrated susceptibility to foliar applications of the water-soluble auxin herbicides 2,4-D, picloram, a combination of 2,4-D and picloram, and diuron (Tomkins and Grant, 1974). S. nemoralis was easily controlled in non-till plots in southern Illinois subjected to various applications of glyphosate (Kapusta and Krausz, 1993).
France: EPPO European and Mediterranean Organization, OEPP/EPPO, 1 rue Le Nôtre, 75016 Paris, France, http://www.eppo.org
UK: PlantNetwork The Plant Collections Network of Britain & Ireland, University Computing Service, New Museums Site, Pembroke Street, Cambridge, CB2 3QH, http://www.plantnetwork.org
USA: USDA United States Department of Agriculture, Natural Resources Conservation Service, Natural Resources Conservation Service, Public Affairs Division, P.O. Box 2890, Washington, DC 20013, http://www.nrcs.usda.gov