Difference between revisions of "Polygonum fowleri subsp. hudsonianum"
Sida 20: 994. 2003.
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Latest revision as of 10:09, 30 July 2020
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
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
"/2" is not declared as a valid unit of measurement for this property.