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No. 284 March 22, 2002
aceska at victoria.tc.ca Victoria, B.C.
Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
JOINT MEETING OF BOTANY BC and BOTANY WASHINGTON
Joint meeting of British Columbia and Washington botanists will
take place at Selkirk College in Castlegar, B.C. from June 16 to
June 19, 2002. More information and registration forms are
Interest will most likely exceed capacity, so if you are keen,
please register early!
REPLACEMENT OF NATIVE NORTH AMERICAN _PHRAGMITES AUSTRALIS_ BY
INTRODUCED INVASIVE GENOTYPES
From: Bernd Blossey [bb22 at cornell.edu]
Until recently, botanists, ecologists, and wetland managers were
debating whether an important invasive plant, _Phragmites
australis_ (Cav.) Trin. ex Steud., or common reed, was intro-
duced or native to North America. Peat core analyses suggest
that _P. australis_ has been an uncommon member of mixed tidal
wetland plant communities in North America for at least 3000
years (Niering et al. 1977, Orson et al. 1987). In the 19th but
particularly in the late 20th century, _P. australis_ began
invading fresh and brackish wetlands in North America greatly
expanding its range and abundance. Mixed wetland plant com-
munities are replaced by near monocultures of _P. australis_,
resulting in changed ecosystem processes and associated
detrimental impacts on native wildlife (Marks et al. 1994,
Meyerson et al. 2000). The population explosion of _P.
australis_ is often thought of being facilitated by changes in
land use patterns and hydrologic regimes, increased distur-
bances, urbanization and eutrophication (Marks et al. 1994).
However, the very same factors are thought to cause declines of
_P. australis_ in Europe (van der Putten 1997). Alternatively,
it has been suggested that the invasiveness of _P. australis_ is
attributable to introduction of more aggressive European
genotypes (Metzler and Rosza 1987, Tucker 1990, Besitka 1996)
but until recently little information was available to support
this hypothesis. Regardless of the status of _P. australis_ as
native or introduced, control attempts are widespread and the
search for potential biological control agents has begun in
North America and Europe (Tewksbury et al. 2002).
Discovery of native and introduced genotypes using genetic
Research by Kristin Saltonstall at Yale University (Saltonstall
2002) has now confirmed the present-day existence of native
North American haplotypes (lineages) and of introduced European
haplotypes. A total of 27 haplotypes were identified of which 11
(A-H, S, Z, AA) are native to North America (Saltonstall 2002).
Within the North American populations, a continuum of geographic
substructuring exists for the native haplotypes. Types AA, F, Z
and S are known historically from the Northeast; types E, G, and
H are found throughout the Midwest; and types A-D are found in
the South and Intermountain West only. Two haplotypes show
worldwide distribution (I and M) with M as the most common type
in North America, Europe and Asia. Type I is found along the
Gulf Coast and also occurs in South America and Asia. (For more
details see Saltonstall 2002.)
Comparing the genetic structuring of present-day populations
with those available in herbarium specimens collected prior to
1910 reveals significant changes in haplotype frequencies in
North America. While the herbarium samples show a widespread
distribution of native haplotypes across North America, modern
populations show a striking range expansion of the M haplotype
(Saltonstall 2002). Type M has entirely replaced native types in
New England and expanded to the southeast where no historic _P.
australis_ populations were known to occur. Type M (which is
most closely related to other European types) has spread to the
West and is also becoming prevalent in the Midwest. It is likely
that the introduction of type M material has occurred sometimes
in the early part of the 19th century, probably at several
Atlantic coast ports. Over the last 150 years, among-population
variation in North America has declined significantly and today
the genetic structure of North American populations resembles
that of Europe (Saltonstall 2002).
Discovery of morphological differences between native and intro-
With the recent discovery of the presence of native and non-
native populations of _Phragmites_ in North America we also
discovered easy to use morphological characters potentially
distinguishing native and introduced genotypes. Preliminary
observations of populations in New York, Wisconsin, Virginia,
Arizona, and Louisiana as well as examination of numerous her-
barium specimens indicate that such morphological differences
may exist. Please note that these traits are based on examina-
tion of few native clones and need further confirmation. We also
need to increase the sample size to assess whether the mor-
phological differences between native and introduced genotypes
are consistent across populations and lineages. More details and
pictures are provided at: http://www.invasiveplants.net .
In general, native populations appear to have a lower stem
density, thinner more flexible stems, and produce a reddish-
purple color on their stems and ligules in spring and summer
that is not present in non-native populations. When checking for
these differences note that the side of the stems exposed to the
sun will show the brightest coloration. The reddish color fades
somewhat into a chestnut brown in the fall but was still very
obvious in October in Virginia; in the winter the red stems turn
light brown and somewhat gray. The ligules of native genotypes
are bright purple while ligules of introduced genotypes appear
green or slightly yellow. Stems of native genotypes are smooth
and shiny as if polished, particularly in the winter, while
stems of introduced genotypes are tan and dull, rough and ribbed
(ridges visible with the naked eye once the leaf sheath has been
removed). These differences are easy to recognize by running
your fingers up and down them stems. (Please note that a leaf
sheath wraps around the stem almost entirely. It is important to
remove the leaf sheath when checking for stem morphology or
texture.) In instances where native and introduced clones grow
in close vicinity of each other, differences in stem toughness
become obvious on windy days. Introduced genotypes remain sturdy
and erect and move little while native genotypes easily bend and
swing in the wind. Stems of introduced genotypes are almost
perfectly straight while stems of native genotypes often grow
crooked. In the fall and winter, differences in the density of
the inflorescence are also obvious; introduced genotypes appear
to have a much denser and larger inflorescence. Observations in
New York and Virginia also suggest that native genotypes senesce
earlier than introduced genotypes (this is a common phenomenon
in introduced species which often show extended growing
periods). In addition, an unidentified fungus attacks native
genotypes with dark spots often clustered around internodes
while introduced genotypes do not show this attack. However,
introduced genotypes are frequently attacked by a number of
generalist fungi (Tewskbury et al. 2002). However this attack
(visible as large, variable blackish areas) is restricted to
We need your help
Our observations are based on few native clones and we need to
confirm these morphological differences by examining different
genotypes in the field and by growing them under standardized
conditions in a common garden. We are currently developing a
standardized data record sheet (available by the end of March at
http://www.invasiveplants.net). We are unable to visit sites
across North America ourselves and depend on your help to refine
our ability to use easily visible field characteristics to
identify native and introduced genotypes. We are particularly
1. Locations of native genotypes across North America. It
appears that most native populations in the East have
vanished or have been overrun by introduced genotypes. For
genotype-specific management it will be important to record
the presence of native genotypes.
2. Information about presence/absence of field characteristics
as outlined above or of any other additional traits that may
help discriminate among native and introduced genotypes.
3. Seed collections from native and introduced genotypes from
as many different regions as possible. This will allow us to
establish germination trials to better understand the dif-
ferences in competitive ability of native and introduced
4. Rhizome collections from as many native and introduced
genotypes as possible. We need approximately 1-2 pounds of
rhizome material to establish a common garden.
5. Stem collections (in the dormant season) to assess dif-
ferences in insect herbivores attacking native and intro-
duced genotypes. We have preliminary evidence from stands in
New York that the insect communities in introduced and
native genotypes differ significantly.
We are currently developing standardized sampling protocols.
These protocols will be posted on the web and we hope that many
of you will be able to contribute to this important work. For
immediate questions, to obtain instructions for collections or
advice please contact bb22 at cornell.edu .
The work outlined above is a collaboration of the Biological
Control of Non-Indigenous Plant Species Program at Cornell
University, Kristin Saltonstall at Yale University, and the
University of Rhode Island. For further information or updates
Besitka, M.A.R. 1996. _An ecological and historical study of
_Phragmites australis_ along the Atlantic Coast._ M.Sc.
thesis. Drexel University, Philadelphia, PA.
Marks, M., Lapin, B., and Randall, J. 1994. _Phragmites
australis_ (_P. communis_): Threats, management, and monitor-
ing. _Natural Areas Journal_ 14: 285-294.
Metzler, K., and R. Rosza, R. 1987. Additional notes on the
tidal wetlands of the Connecticut River. Newsletter of the
Connecticut Botanical Society 15: 1-6.
Meyerson, L. A., K. Saltonstall, L. Windham, E. Kiviat, & S.
Findlay. 2000. A comparison of _Phragmites australis_ in
freshwater and brackish marsh environments in North America.
_Wetlands Ecology and Management_ 8: 89-103.
Niering, W. A., R. S. Warren, and C. Weymuth. 1977. Our dynamic
tidal marshes: Vegetation changes as revealed by peat
analysis. _Connecticut Arboretum Bulletin_ # 22.
Orson, R. A., R.S. Warren, & W.A. Niering. 1987. Development of
a tidal marsh in a New England river valley. _Estuaries_ 10:
20-27. Saltonstall, K. 2002. Kryptic invasion by non-native
genotypes of the common reed, _Phragmites australis_, into
North America. _Proceedings of the National Academy of
Sciences of the United States of America_ 99: 2445-2449.
Tewksbury, L. T., R.A. Casagrande, B. Blossey, M.
Schwarzlaender, & P. Haefliger. 2002. Potential for biologi-
cal control of _Phragmites australis_ in North America.
_Biological Control_ 23: 191-212.
Tucker, G. C. 1990. The genera of Arundinoidae (Gramineae) in
the southeastern United States. _J. Arnold Arboretum_ 71: 14-
van der Putten, W. 1997. Die-back of _Phragmites australis_ in
European wetlands: an overview of the European research
program on reed die-back and progression (1993-1994).
_Aquatic Botany_ 59: 263-275.
Bernd Blossey, Department of Natural Resources, Fernow Hall,
Cornell University, Ithaca, NY 14853, USA
email: bb22 at cornell.edu Web: http://www.invasiveplants.net
DISCOVERY OF NEW CONIFER IN REMOTE FORESTS OF NORTHERN VIETNAM
From: Press Release, Royal Botanic Gardens, Kew
An extraordinary conifer has been recently discovered in north-
ern Vietnam, identified as new to science by Aljos Farjon, Kew's
conifer specialist. The new species, a "missing link" between
true cypresses (_Cupressus_) and the false cypresses
(_Chamaecyparis_) was found in a remote area of northern Vietnam
in ridge-top forest of extraordinary biodiversity. This is a
remnant of a once-extensive forested region which covered much
of eastern Asia and extended to North America. Only fragments of
the forests now remain and the new conifer is one of the relict
species left after the last Ice Age.
There are only about 630 living species of conifer but their use
for timber makes them the most important tree species in the
The new conifer is a small tree with highly unusual foliage of
two sorts on the mature trees; both needle and scale leaves. It
was discovered by a team of scientists, which included Kew's
orchid expert Dr Phillip Cribb and colleagues from the Viet-
namese Institute of Terrestrial Ecology in Hanoi, the Komarov
Institute in St. Petersburg and the Missouri Botanical Garden,
on an expedition studying the orchid floras of the karst moun-
tains of northern Vietnam.
Aljos Farjon has confirmed that the conifer is a new species in
a new genus and has named it, with colleagues from Vietnam and
Missouri Botanical Garden, _Xanthocyparis vietnamensis_, the
Golden Vietnamese cypress. Apart from the extraordinary Wollemi
pine (_Wollemia nobilis_), recently described from New South
Wales, it is the first truly new conifer described since 1948.
Its closest ally, the Nootka cypress (_Chamaecyparis
nootkatensis_), also now transferred to the genus
_Xanthocyparis_, is found in North America. Gardeners will know
it as one of the parents of the widely grown and much loathed
Leyland's cypress (_X Cupressocyparis leylandii_). The conse-
quence of the Vietnamese discovery is that the scientific name
of Leyland's cypress will also have to change.
Sadly, the Golden Vietnamese cypress is already critically
endangered in the wild. It is naturally rare, confined to lime-
stone ridges in a small area not far from the Chinese border. It
is also prized locally for its fragrant wood which is used for
coffins and for making shrines. Only a few semi-mature and
coppiced trees survive.
At a meeting of the World Conservation Union (IUCN) in Taiwan
just before Christmas, the Vietnamese scientists, backed up by
Kew and Missouri scientists, will propose that its mountain
habitat should be established as a conservation area. The Mis-
souri Botanical Garden is currently working on cultivation and
propagation techniques aimed at the long-term survival of this
BOOK REVIEW: SACKS AMONG THE FERNS
From: Martin Levin in Toronto Globe & Mail, Saturday,
March 9, 2002 [abbreviated]
Sacks, Oliver. 2002. Oaxaca Journal. National Geographic,
Washington, D.C. 159 p. ISBN 0-7922-6521-1 [hard cover]
Price: US$20.00 CDN$32.00
Available in all "better" bookstores.
Drawn by the spirit of amateurism and his own passion (a third-
generation "fernie" in his family), Oliver Sacks joins the
American Fern Society in a small expedition to Oaxaca in
southern Mexico. This book is a slightly emended record of what
Sacks (an inveterate journal-keeper) observed. Like all the best
journals, it has a rich immediacy, a sense that we share the
moment of the author's perceptions. Since Sacks is such a lovely
writer, and he and his fellow travellers such fonts of knowledge
about everything from Mexican history to Mayan culture to choco-
late making to the workings of fern evolution, the book is a
And ferns and other flora and fauna are what our traveller and
his fellow pteridologists most enjoy. He loves ferns because
they're ancient, evoking an all-green hothouse planet before the
advent of showy, explicit flowers. ... Virtually a beginner's
guide to botany, the book is peppered with Sack's own drawings
At its core, Oaxaca Journal is a potent paean to amateurism.
Sacks is almost worshipful in his admiration of those amateurs
whose fieldwork has contributed mightily to the progress of
science, from the Reverend William Gregor, who discovered
titanium, to William Smith, the "father of geology" now immor-
talized in Simon Winchester's The Map That Changed the World. It
makes you want to strap on your field glasses and catch the
first flight south.
[From the dust jacket: "Oliver Sacks is a clinical professor of
neurology at the Albert Einstein College of Medicine and an
adjunct professor of neurology at the New York University School
of Medicine. A fellow of the American Academy of Arts and Let-
ters, he is the Wife for a Hat_, _An Anthropologist on Mars_,
and _Uncle Tungsten: Memories of a Chemical Boyhood_. He is a
member of the American Fern Society, the British Pteridological
Society, the New York Mineralogical Club, and the New York
Stereoscopic Society." Another Sack's book full of botany: _The
Island of the Colorblind_.]
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