POLYGONUM AVICULARE SUBSP. RURIVAGUM (POLYGONACEAE) IN NORTH AMERICA

3 Pages·2003·1.5 MB·

by  Mihai Costea

POLYGONUM RURIVAGUM
AVICULARE
SUBSP.
NORTH AMERICA
(POLYGONACEAE)
IN
Department of Plant Agriculture Department of Plant Agnculture
ofGueiph
ofQuelph
University University
Guelph, Ontario,NlG2Wi, CANADA Guelph, Ontario, Ni G 2Wl CANADA
[email protected] [email protected]
ABSTRACT
ibsp.runvaguminNorthA
Non
de Polygonum aviculare subsp. rurivagum en
a
de Europa que crece en lugares ruderales, soleai
irio
The occurrence the European Polygonum aviculare subsp. rurivagum
of L. (Jord.
ex Boreau) Berher in North America has been uncertain. Love and Love (1956)
reported from eastern North America but they did not indicate any location.
it
some
Furthermore, have been generally disregarded because of
their results
chromosome and no specimens vouchers have been
doubtful counts, because or
&
&
quoted or found Mertens Raven 1965; Wolf McNeill 1986). During the
(e.g.,
we
preparation of the genus Polygonum for Flora of North America have en-
North America and we compared
countered this taxon in scattered locations in
with European material. Some relatively recent European floras and treat-
it
rurivagum
ments of Polygonum have preferred to treat this taxon as a species (P
&
Akeroyd Do Amaral Franco Da Luz Rocha Afonso
ex Boreau, 1993;
Jord.
e.g.,
followmg study Nevertheless,
1995; Stace 1997) the of Styles (1962). its classifi-
cation under P aviculare apparently the best solution (Karlsson 2000; Costea
is
&
homogenous extreme morphology, with
Tardif 2003). a rare but taxon. Its
It is
mm,
and
paucif lorous cymes (1-3 flowers), small flowers, 2.3-3.2 narrow-ellip-
mm
P
tic to linear-lanceolate leaves, 1.5-5 wide, brings it close to aviculare subsp.
neglectum (Besser) Arcang., with which has been frequently misidentified.
it
mm,
The subsp. rurivagum differs by the long ochreas, 8-12.5 with strong veins
and the free part disintegrating into persistent fibers, and by the leaves with
The
veins strongly raised on the abaxial part of the leaves. subspecies
lateral
mm,
4-8 and
neglectum has ochreas of with inconspicuous veins free part leav-
ing almost no fibrous remains and leaves without strongly raised lateral veins.
For differences between subsp. rurivagum and the other subspecies of
P.
civuuUirc Irom North America see Costea and Tardif (2003). For iconography
sec RalTaelli (1982, Fig. 12), Karlsson (2000, Fig. 96). The plant grows as a rud-
cral in dry sunny and often trampled habitats in pavement cracks gravel and
sand\ places Flowering occuis fiom June Octobei
to
We
warmly
thank James and
Reveal Cecil Slaughter, providing
Jr for critical
We
ACAD,
edits to earlier drafts of the manuscript. also thank the curators from
DAO, MTMG,
ALTA, CAS, DC, DS, GH, JEPS, LL, MT, NFLD, NSPM, NY, PO,
F,
UC
QFA, QUE, RSA, SASK, TEX, UBC, and US
preparing
S, for the (usually) vo-
luminous Polygonum loans. Laura Echarte checked the Spanish translation of
Edmondson,V.H.
Europaea
Flora
Is.
\
.
Do Amaral Franco, and M. Da Luz Rocha Afonso. 1995. Especies da sect, Pc
J.
em
53-1
existentes Portugal. Stud. Bot. 4:1 75.
1
and 956. Chromosomes and taxonomy of eastern North
Love, a. D. Love. /
1
Polygonum. Canad. 34:501-521
Bot.
J.
genus Po/ygoDum Nordica
KARLssoN,T.2000.The L.ln:Jonsell,B.ed., Flora vol.1,
St'
255-273.
Pp.
Taxonomy Polygonum Polygonum
MERTENsJ.R.and RH. Raven. 1965. of section {A
conoscenza genere Polygonum sped
982.Contributi del L.4.Le
Raffaelli,M. alia
1
Webbia
Po/ygonum. 35:361-406.
della sectia
New
Cambridge
Stace,C.A. 1997. flora of British lsles,2nd ed., University Press,Ca
The taxonomy Polygonum and
Styles, B.T. 1962. of aviculare its allies in Britain.
5:177-214.
Wolf, and McNeill. 986. Synopsis and achene morphology of Polygonun
S.J.
J.
1
Polygonum (Polygonaceae) Canada. Rhodora 88:457-479.
in