Persicaria lapathifolia |
Persicaria setacea |
|
---|---|---|
common knotweed, curltop knotweed, curltop ladysthumb, curlytop knotweed, dock-leaf smartweed, pale smartweed, renouée à feuilles de patience, willow weed |
bog smartweed, bristly smartweed |
|
Habit | Plants annual, (0.5–)1–10 dm; roots also sometimes arising from proximal nodes; rhizomes and stolons absent. | Plants perennial, 5–15 dm; roots also often arising from proximal nodes; rhizomes present, stolons sometimes produced on plants in water. |
Stems | ascending to erect, simple or branched, scarcely ribbed, glabrous or, rarely, appressed-pubescent distally, sometimes glandular-punctate or stipitate-glandular distally. |
ascending or erect, branched distally, slightly ribbed, glabrous or loosely appressed- to spreading-hirsute near nodes. |
Leaves | ocrea brownish, cylindric, 4–24(–35) mm, chartaceous, base inflated, margins truncate, eciliate or ciliate with bristles to 1 mm, surface glabrous, rarely strigose, eglandular; petiole 0.1–1.6 cm, usually strigose, sometimes glabrous; blade sometimes with dark triangular or lunate blotch adaxially, narrowly to broadly lanceolate, 4–12(–22) × (0.3–)0.5–4(–6) cm, base tapering to cuneate, margins antrorsely scabrous, apex acuminate, faces strigose on main veins, glabrous or tomentose abaxially, glandular-punctate abaxially. |
ocrea brown, cylindric, 10–20 mm, chartaceous, base usually inflated, margins truncate, ciliate with bristles 6–12 mm, surface strigose and with loosely ascending to spreading hairs at least proximally, not glandular-punctate; petiole 0.1–0.5 cm, spreading-hirsute, leaves sometimes sessile; blade without dark triangular or lunate blotch adaxially, lanceolate, (3–)6–15(–18) × (1.5–)2–3.2(–4.8) cm, base tapered to truncate, margins appressed-ciliate, apex acute to acuminate, faces sparsely hirsute to loosely appressed hirsute abaxially and adaxially. |
Inflorescences | mostly terminal, sometimes also axillary, mostly arching or nodding, usually uninterrupted, 30–80 × 5–12 mm; peduncle 2–25 mm, often stipitate-glandular; ocreolae usually overlapping, margins eciliate or ciliate with bristles to 0.4 mm. |
mostly terminal, erect, uninterrupted, 20–80 × 4–8 mm; peduncle 10–70 mm, strigose; ocreolae overlapping, margins ciliate with bristles (0.6–)1–3(–5) mm. |
Pedicels | ascending, 0.5–2.3 mm. |
ascending, 1–3 mm. |
Flowers | 4–14 per ocreate fascicle, homostylous; perianth greenish white to pink, glabrous, not glandular-punctate or glandular-punctate with punctae mostly on tubes and inner tepals, scarcely accrescent; tepals 4(–5), connate ca. 1/4–1/3 their length, obovate to elliptic, 2.5–3 mm, veins prominent, those of 2 or 3 outer tepals prominently bifurcate distally, anchor-shaped, margins entire, apex obtuse to rounded; stamens 5–6, included; anthers pink or red, elliptic; styles 2(–3), connate at bases. |
(1–)2–4(–5) per ocreate fascicle, homostylous; perianth greenish proximally, creamy or tan distally, occasionally tinged pink, glabrous, not glandular-punctate, nonaccrescent; tepals 5, connate ca. 1/3 their length, obovate, 2–3 mm, veins not prominent, not anchor-shaped, margins entire, apex obtuse to rounded; stamens 5, included; anthers pink or red, elliptic; styles 3, connate proximally. |
Achenes | included or apex exserted, brown to black, discoid or, rarely, 3-gonous, 1.5–3.2 × 1.6–3 mm, shiny or dull, smooth. |
included or apex exserted, brown to black, 3-gonous, (1.5–)2–2.5 × 1.2–1.7 mm, shiny, smooth. |
2n | = 22. |
= 20. |
Persicaria lapathifolia |
Persicaria setacea |
|
Phenology | Flowering (Apr-)Jul–Nov. | Flowering Jul–Oct. |
Habitat | Moist places, roadsides, floodplains, waste places, cultivated fields | Alluvial woods, swamp forests |
Elevation | 0-1500(-1800) m (0-4900(-5900) ft) | 0-300 m (0-1000 ft) |
Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; SPM; Mexico; South America; Africa; Greenland; Asia; Europe; Pacific Islands (New Zealand)
|
AL; AR; DE; FL; GA; IL; IN; KY; LA; MA; MD; MI; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WA
|
Discussion | Persicaria lapathifolia is a morphologically variable complex with more than two-dozen infraspecific taxa described in the New World and Old World. An allozyme study by L. L. Consaul et al. (1991) did not support recognition of elements often referred to Polygonum lapathifolium var. salicifolium or P. scabrum, which are synonymized here. Yang J. and Wang J. W. (1991) reached a similar conclusion regarding var. salicifolium and P. nodosum based on their morphometric analysis. The Keres, Navajo, and Potawatomi prepared medicinal infusions with Persicaria lapathifolia, and the Zuni used decoctions made from the plants as cathartic and emetic drugs (D. E. Moerman 1998). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
C. B. McDonald (1980) showed that Persicaria setacea is closely related to P. hirsuta and P. hydropiperoides. Hybrids between P. setacea and P. hirsuta have been produced experimentally but appear to be rare in the wild. Persicaria setacea and P. hydropiperoides occasionally occur in mixed populations but do not hybridize (McDonald). Persicaria setacea sometimes intergrades morphologically with P. hydropiperoides, especially in New England. Specimens of P. setacea without the characteristic ascending or spreading hairs on the ocreae usually can be distinguished from P. hydropiperoides by the extent of adnation of the hairs to the ocreae—up to one-third their lengths in P. setacea, but one-third to two-thirds their lengths in P. hydropiperoides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 589. | FNA vol. 5, p. 588. |
Parent taxa | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria | Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Persicaria |
Sibling taxa | ||
Synonyms | Polygonum lapathifolium, Polygonum incarnatum, Polygonum lapathifolium var. ovatum, Polygonum lapathifolium var. salicifolium, Polygonum linicola, Polygonum nodosum, Polygonum pensylvanicum var. oneillii, Polygonum scabrum, Polygonum tomentosum | Polygonum setaceum, Polygonum hydropiperoides var. setaceum, Polygonum setaceum var. interjectum, Polygonum setaceum var. tonsum |
Name authority | (Linnaeus) Gray: Nat. Arr. Brit. Pl. 2: 270. (1822) | (Baldwin) Small: Fl. S.E. U.S., 379. (1903) |
Web links |
|