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Epilobium parviflorum, a Rare European Introduction along the Niagara
River P. M. Eckel Originally published in New York Flora Association Newsletter 13(2):
3-5. 2002. |
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Epilobium
parviflorum, a Rare European Introduction along the Niagara
River – by
Patricia M. Eckel, Buffalo Museum of Science The Niagara
River Gorge is, and has been, host to a dazzling array of both native and
exotic plant species throughout the centuries-long history of botanical
interest in the area. It offers seven miles of stratified sandstone and
dolomite habitats, providing a pattern of both acidic and basic substrates on
a variety of steep slopes. There is a patchwork display of shaded pockets of
stable, moist black soil with high humus and exposed, sterile crumbling soft
shales, with about half of these areas exposed to the west and half to the
east. Transportation corridors span
the gorge, now, with a complex of bridges, exposing the region to a rain of
propagules of exotic species, some of which are spread by trains and highway
vehicles, and some of which escape nearby gardens and yard plantings. In
addition, the region is frequented by waterfowl who bring in quantities of
seeds and plant parts picked up during their migrations. There has been a recent proliferation of
persistent, exotic taxa among the native flora, brought about, at least in
part, by climate factors. Nowhere is
this more apparent than along the two old, west-facing railroad beds near the
northern terminus of the gorge, at Lewiston, New York. There,
in what was formerly a relatively barren area of crumbling red shales, a
soft, mobile talus derived from the beds has recently developed a veritable
jungle of exotic species. The weedy populations have developed in extensive
seepage along the dolomite caprock and in its effluent, which flows in the up
per ditches that parallel the railroad bed and the gorge wall. As
part of an attempt to describe the vegetation of this habitat and correlate
it with other patch communities on both sides of the gorge, I initiated a
botanical survey in 2001. Preliminary collections included an Epilobium species
that was unfamiliar to me at the time, and not recorded from the Niagara
Gorge region. It turned out to be E. parviflorum Schreber. Label
Data: USA, New York, Niagara Co., town of Lewiston, upper railroad path
at mouth of Niagara River and gorge just south of Artpark in the village of
Lewiston; calcareous bedrock with extensive shale-sandstone strata, with Salix
eriocephala, S. bebbii, S. interior. P. M. Eckel, coll. Sept. 23,
2001 (BUF). The only
previously reported station for this European species in western New York was
from Monroe Co., where it was collected by Robert Wesley (NYFA, 1990, Richard
Mitchell, personal communication). For about a century, it had been reported
for North America only in the vicinity of New York City (Kings and Queens
Counties) and on ballast at Hoboken, New Jersey, by W. Trelease in 1891
(Purcell, 1976); subsequently, it was recorded eight stations in the province
of Ontario, Canada, from the counties of Grey, Simcoe and York. The habitats
were a clay field, a riparian meadow, mud beside a beaver pond, a wet cedar-tamarack swamp, stream edges and a
“wildlife area” on Toronto Island in Lake Ontario. The three Ontario populations
were near to significant bodies of water in the Great Lakes, making it likely
that spread of the plant has been by waterfowl, even though seed dispersal in
this group is usually by wind. The species was found in Michigan in 1966 and
has since spread to several counties there (Voss, 1985). Epilobium
parviflorum has stems with spreading hairs and relatively
inconspicuous, red-purple flowers. The horizontally pubescence of the stem
can cause the species to be confused with native E. strictum Muhl. and the Eurasian E.
hirsutum L. Epilobium strictum,
however, has entire, nearly linear leaves up to 8 mm wide and the stigma is
entire. Both E.
hirsutum and E. parviflorum have leaves much wider than 8 mm, and
both are distinctly denticulate with deeply 4-lobed stigmas. Epilobium
hirsutum has more conspicuous petals, up to 1 cm long, whereas those of E.
parviflorum (as the epithet indicates) are smaller, only reaching a
centimeter in length. The leaves of E. hirsutum clasp the stem to
halfway around its circumference whereas those of E. parviflora are
subsessile. Examination of other
collections made along the Niagara River beach, on the southern boundary of
the village of Lewiston, revealed a second collection of E. parviflorum,
deposited at BUF, indicating that the species is probably well established
along the river. It is most likely also established on the Canadian shores of
the river, but this remains to be demonstrated. Literature
Cited: New York Flora Association. 1990. Preliminary
Vouchered Atlas of New York State Flora. Ed. 1. New York State Museum
Intsitute, Albany. Purcell, Nancy J. 1976. Epilobium parviflorum Schreb.
(Onagraceae) established in North America. Rhodora 78:785-787. Trelease, W. 1891. A revision of the American
species of Epilobium occurring North of Mexico. Report of the Missouri
Bot. Gard. 22:67-117. Voss, Edward G. Michigan Flora. 1985. Part II.
Dicots (Saururaceae-Cornaceae). Cranbrook Institute of Science Bulletin 59. |
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