Polygonum fowleri subsp. hudsonianum

(S. J. Wolf & McNeill) Costea & Tardif

Sida 20: 994. 2003.

Common names: Hudsonian knotweed renouée de la baie d’Hudson
Endemic
Basionym: Polygonum caurianum subsp. hudsonianum S. J. Wolf & McNeill Rhodora 88: 469, fig. 3. 1986
Synonyms: Polygonum hudsonianum (S. J. Wolf & McNeill) H. R. Hinds
Treatment appears in FNA Volume 5. Treatment on page 555.

Plants often purplish tinged, homophyllous, rarely subsucculent. Stems prostrate, 5–30 cm. Leaves: ocrea 2.5–5 mm; petiole 2–5 mm; blade purple-tinged, narrowly obovate or oblanceolate, 8–30 × 4–12 (–15) mm, apex rounded to obtuse; middle stem-leaves 1.1–1.8 (–2.2) times as long as adjacent branch leaves. Cymes 2–7 (–10) -flowered. Pedicels 1–1.5 mm. Perianths (2.2–) 2.5–3.3 (–3.5) mm. Achenes ovatelanceolate, (2–) 3-gonous, (1.8–) 2–2.5 (–3.1) mm, faces often unequal, ± flat to concave, roughened, rarely obscurely tubercled.


Phenology: Flowering Jul–Sep.
Habitat: Gravelly seashores
Elevation: 0-30 m

Distribution

V5 1132-distribution-map.gif

Man., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que.

Discussion

Wolf and McNeill described Hudsonian knotweed as a subspecies of Polygonum caurianum (P. humifusum subsp. caurianum in this treatment). In raising it to the rank of species, H. R. Hinds (1995) noted that “separation between P. fowleri and P. hudsonianum, however, is more difficult.” M. Costea and F. J. Tardif (2003) concluded that the taxon is best treated as a subspecies of P. fowleri, based on the existence of intermediate plants.

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property.

0.25 cm2.5 mm <br />0.0025 m <br /> (0.31 cm3.1 mm <br />0.0031 m <br />) +
brown;dark-brown +
exserted +  and included +
dull +  and shiny +
smooth;roughened +
(2-)3-gonous +  and ovatelanceolate +
whitish yellow +
elliptic +  and oblong +
rounded;obtuse +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
(S. J. Wolf & McNeill) Costea & Tardif +
not stipelike +
Polygonum caurianum subsp. hudsonianum +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
purple-tinged +
0.8 cm8 mm <br />0.008 m <br /> (3 cm30 mm <br />0.03 m <br />) +
oblanceolate;obovate +
coriaceous +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Hudsonian knotweed +  and renouée de la baie d’Hudson +
2-7(-10)-flowered +
distributed +
Man. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Nunavut +, Ont. +  and Que. +
shiny +  and dull +
concave +
0-30 m +
less flat +  and concave +
unequal +
persistent +
adnate +, free +  and distinct +
disarticulating +  and solid +
decumbent to erect +  and prostrate +
unwinged +  and winged +
black +, red +, brown +  and yellowish +
exserted +  and included +
pubescent +  and glabrous +
spheroidal +, 4-gonous +, lenticular +, biconvex +, discoid +, 3-gonous +  and 2-gonous +
Gravelly seashores +
compound +, branched +  and simple +
nonmembranous +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
sessile +  and petiolate +
deciduous +
white +  and pink +
pubescent +  and glabrous +
cucullate +, oblong +  and not keeled +
1.1-1.8(-2.2) times as long as adjacent branch leaves +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading +
accrescent +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
spreading;erect +
0.33 cm3.3 mm <br />0.0033 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
fleshy +, indurate +  and membranous +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering Jul–Sep. +
(2-)3(-4)-carpellate +
slender;stout +
woody +  and fibrous +
6 +  and 8 +
not wiry +  and branched +
straight +
prostrate +  and ascending +
papillous-scabridulous +
5 cm50 mm <br />0.05 m <br /> (30 cm300 mm <br />0.3 m <br />) +
2 +  and 3 +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
Polygonum hudsonianum +
Polygonum fowleri subsp. hudsonianum +
Polygonum fowleri +
subspecies +
overlapping +
connate +  and distinct +
lobed +  and laciniate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
not cushionlike +