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Epilobium parviflorum along
the Niagara River Reconsidered July
19, 2004 |
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Epilobium
parviflorum along the Niagara River Reconsidered P.
M. Eckel, Missouri Botanical Garden In 2002 I published an article in the NYFA Newsletter on
the Eurasian plant Epilobium parviflorum Schreber, Small-flowered
Hairy Willow-herb, found along the Niagara River at Lewiston, New York. I had
not realized then that this species was arguably new to the flora of New York
state as of the 1997 publication date of the recent checklist by Mitchell and
Tucker. The species was earlier recorded for Monroe County on the vouchered
distribution map printed by the New York Flora Association (NYFA) in
1990. Presently the species is still
not listed on the NYFA website as occurring in New York State, but I am
assured this is a technical artefact (Troy Weldy, pers. comm.) and will be
corrected in a later version of the website this year. See: http://nyflora.org/atlas/atlas.htm. In the checklist of the Ontario flora, Epilobium molle Lam. is given as a
synonym of E. parviflorum (Morton
& Venn 1990). Apparently, the botanist John Torrey also published an
identical name, Epilobium molle, to
describe what is now Epilobium strictum
Muhlenb. ex Sprengel, a native species of swamps. John Torrey published Epilobium
molle Torrey (1843, Vol. 2 p. 233) = E. strictum from sphagnous swamps in New
York State. In the first volume of the Journal of the Torrey Botanical Club
(Vol.1(9): 33) E. molle Torr. was also used for specimens from
Morristown and Chatham, New Jersey. Epilobium
molle Lam., however, does not occur as a synonym for Epilobium parviflorum in the North
American Synthesis (Kartesz 1999). According to R. Mitchell (T. Weldy, pers. comm.) in an upcoming version of the
New York State flora, Epilobium
hirsutum L. will be cited as a synonym of E. parviflorum to indicate that some specimens cited as E. hirsutum are probably E.
parviflorum instead. Epilobium
parviflorum was first recorded by W. Trelease for North America in
1891 from Kings and Queens Counties in New York State, and Hoboken, New
Jersey. Subsequently it was reported for Ontario in the counties of Grey,
Simcoe and York (Purcell 1976), and counties in Michigan (Voss 1985). The
Nature Conservancy in the state of Ohio has published on-line a list of
invasive species of which E.
parviflorum is one. There are nine counties listed, and all but one
appears to be associated with the Cuyahoga River drainage basin. This willow-herb is probably more widespread in eastern
North America than records show, as it does not occur in the keys and
descriptions of the major manuals; the only manual I am aware of that treats
this species is that of Voss (1985), which was used to identify the Niagara
specimens. Plants ordinarily might
key to the common Eurasian Epilobium
hirsutum L., Great Hairy Willow-herb, which has conspicuously larger
flowers (11-17 mm long) and sessile leaves, the larger leaves clasping the
stem about half way around. Epilobium
parviflorum, as the epithet suggests, has smaller flowers (at most 10 mm
long), and the leaves are subsessile or on tiny stalks in the upper leaves,
not at all clasping. The small flowers resemble those of the more common E. ciliatum or E. coloratum, but those two species have a pubescence on the stem
that is of minute incurved hairs. The pubescence of E. parviflorum is of long hairs, these or nearly at right angles
to the stem. The extensive distribution of Epilobium parviflorum along the Niagara River in New York State
suggests that it has been an unrecognized element for some time. The
characteristic right-angled pubescence should be looked for on the stems of
small-flowered Willow-herbs in wet shores, ditches and marshes explored by
our membership including feeder streams into the Niagara or along the shore
of Lakes Erie and Ontario. The Canadian shoreline could also be examined in
late summer. It is possible, from personal observation, that this species may
also occur in urban settings (back-yard gardens). With climactic change imposing new limits on the
reproductive vigor of native and alien taxa alike, the flora of the Niagara River,
famous for its extraordinary regional diversity of plant species, may be
unusually susceptible to changes in its flora. Means of dispersal such as
along the river abound (Eckel 2002). The Niagara River as a strait,
connecting Lakes Erie and Ontario and the interior of the continent at Lake
Superior on the west and its outlet into the Atlantic Ocean to the east, may
be an unusual venue for biological invasion. Note that all the counties
mentioned in recent literature, other than Trelease's early records near the
Atlantic, occur either adjacent to the Lakes and major bodies of water
adjacent to the lakes. In Michigan the species is reported in the northern
counties below the peninsula near the strait between Lakes Huron and
Michigan. River invasions, such as in Ohio, may have derived from a Lake
source. Ultimately, as the first
records for this species indicate, the source may have come from as yet
unrecorded habitats near the Atlantic Ocean at the mouth of the St. Lawrence.
The Niagara River flora is special for a number of
reasons, but its peculiar sensitivity to the establishment of weedy species
is noteworthy. Perhaps the oldest alien species, the ancestor of the
grocery-store Bing Cherry, Prunus avium
L., is extensive and apparently old, perhaps dating to colonial times
although some early literature emphasizes the sour cherry in early orchards. Alnus glutinosa has attained invasive
status along the Niagara River as has been detailed in Clintonia (Eckel
2003). Even the rare native Iris
virginica var. shrevei (Eckel
2000) may prove to be unique to the Niagara River in our region, with I. versicolor appearing to prefer
inland stations, although further field work is needed to substantiate this. Epilobium parviflorum has perhaps
attained this special status, and there may well be other such species along
this famous watercourse. Specimens of Epilobium
hirsutum in the Clinton Herbarium of the Buffalo Museum of Science were
examined as possibly E. parviflorum instead.
All specimens were E. hirsutum except
one (collected by R. Zander in 1971). The following are the four
representative specimens indicating the present broad north-south
distribution of this plant in western New York: Cattaraugus Co., Cattaraugus Indian Reservation, swamp
along NY Rte. 238. R. Zander. Oct. 27,
1971. Erie Co., town of Tonawanda, Niagara River just N of South
Grand Island Bridge (Interstate 190) shoreline parcel, wet selectively cut Fraxinus pensylvanica woods, shade,
year long wet soil, some Ulmus
americana. Beach. P. M. Eckel, August 12, 2003. Erie Co.: Town of Tonawanda, corner of Sheridan and
Kenmore Rds., near Two Mile Creek Road, near Interstate 190; old-growth
Quercus palustris, Q. bicolor, Acer rubrum; vernal pools; no shrub layer, P.
M. Eckel, Sept. 2001. Niagara Co., town of Lewiston, shore of Niagara River, 3
lots N of N boundary of Artpark, steel slope, covered with Solidago canadensis, S.
graminifolia, Juncus torreyi;
sheet seepage constant. P. M. Eckel, Sept. 19, 2001. Niagara Co., town of Lewiston, upper RR path at mouth of
Niagara River gorge (N end) just S of Artpark, calcareous bedrock with
extensive shale-sandstone; by path; Salix
eriocephala. P. M. Eckel Sept. 23, 2001. I thank Troy Weldy and Richard Mitchell of the Natural
Heritage Program for crucial information. Eckel, P. M. & J. Bissell. 2000. Iris virginica L., Southern Blue Flag, Restored to the Flora of
New York State. Clintonia 15(3): 7. Eckel, P. M. 2002. Epilobium
parviflorum, a rare European introduction along the Niagara River. NYFA
Newsletter 13(2):3-5. Eckel, P. M. 2003. Two problems in Betulaceae along the
Niagara River: Alnus glutinosa and Betula cordifolia. Clintonia.
18(4):3-4. Kartesz, J. T. 1999. A Synonymized Checklist & Atlas
with Biological Attributes for the Vasc. Flora of the U.S., Canada, and
Greenland. First Ed. In: Kartesz, J. T. & C. A. Meacham. Synthesis of the
N. Amer. Flora, Version 1.0, N. Carolina Bot. Garden, Chapel Hill, NC. Mitchell, Richard S. & Gordon C. Tucker. 1997. Revised
Checklist of New York State Plants. New York State Museum Bulletin 490. 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. Torrey, J. 1843. A Flora of the State of New York,
comprising full descriptions of all the indigenous and naturalized plants
hitherto discovered in the state; with remarks on their economical and
medicinal properties. Vols. 1 & 2 of Natural History of New York.
Albany. Trelease, W. 1891. A revision of the American species of Epilobium occurring North of Mexico.
Report of the Missouri Botanical Garden 22:67-117. Voss, Edward G. Michigan Flora. 1985. Part II. Dicots (Saururaceae-Cornaceae).
Cranbrook Institute of Science Bulletin 59 and University of Michigan
Herbarium, Ann Arbor. |
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