The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

arrow-leaf knotweed, arrow-leaf tearthumb, arrow-vine, renouée sagittée

Mexican tearthumb

Habit Plants annual, 3–20 dm; roots also often arising from proximal nodes.
Stems

scandent, ribbed, glabrous;

prickles 1–1.5 mm.

Leaves

ocrea brownish, cylindric, (3–)5–13 mm, chartaceous, base inflated or not, without prickles, margins oblique, glabrous or ciliate at tip with bristles 0.2–1 mm, surface glabrous;

petiole 0.5–4 cm;

blade broadly lanceolate to oblong, 2–8.5 × 1–3 cm, base sagittate to cordate, margins entire, ciliate or eciliate, apex obtuse to acute, faces glabrous or densely appressed-pubescent, usually with retrorse prickles along midvein abaxially.

Inflorescences

capitate or paniclelike, uninterrupted, 5–15 × 4–10 mm;

peduncle 10–80 mm, usually glabrous, sometimes with retrorse prickles proximally;

ocreolae overlapping, margins eciliate.

Pedicels

mostly ascending, 1–1.5 mm.

Flowers

2–3 per ocreate fascicle;

perianth white or greenish white, often tinged pink or red, sometimes entirely pink, glabrous, accrescent, not becoming blue and fleshy in fruit;

tepals 5, connate 1/3–1/2 their length, broadly elliptic, 3–5 mm, apex obtuse;

stamens 8, filaments distinct, free;

anthers pink, ovate;

styles 3, connate to middle.

Achenes

included or styles exserted, light or dark brown to black, 3-gonous, 2.5–4 × 1.8–2.5 mm, dull to shiny, smooth to minutely punctate.

2n

= 40.

Persicaria sagittata

Persicaria meisneriana

Phenology Flowering Jun–Oct.
Habitat Moist shaded sites, meadows, pastures, fens, swamps, shorelines of ponds and streams
Elevation 0-1000 m (0-3300 ft)
Distribution
from FNA
AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; e Asia
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; GA; LA; SC; TX; Mexico; Central America; South America; West Indies; se Africa
[BONAP county map]
Discussion

Persicaria sagittata is an extremely variable species. Achene and leaf characters have been used by some authors to separate North American and Asian populations, but these characters show weak geographic variation (C. W. Park 1988).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (1 in the flora).

Variety meisneriana has leaves with petioles 0.3–1 cm, blades prominently sagittate to hastate at bases, and ocreae usually moderately to densely pubescent. It is found only in South America (Argentina, Brazil, Paraguay).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 577. FNA vol. 5, p. 578.
Parent taxa Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon Polygonaceae > subfam. Polygonoideae > Persicaria > sect. Echinocaulon
Sibling taxa
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. meisneriana, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. setacea, P. virginiana, P. wallichii
P. amphibia, P. arifolia, P. bicornis, P. bungeana, P. capitata, P. careyi, P. chinensis, P. glabra, P. hirsuta, P. hydropiper, P. hydropiperoides, P. lapathifolia, P. longiseta, P. maculosa, P. minor, P. nepalensis, P. orientalis, P. pensylvanica, P. perfoliata, P. punctata, P. robustior, P. sagittata, P. setacea, P. virginiana, P. wallichii
Subordinate taxa
P. meisneriana var. beyrichiana
Synonyms Polygonum sagittatum, Polygonum sagittatum var. gracilentum, Tracaulon sagittatum, Truellum sagittatum Polygonum meisnerianum
Name authority (Linnaeus) H. Gross: Beih. Bot. Centralbl. 37(2): 113. (1919) (Chamisso & Schlechtendal) M. Gómez: Anales Inst. Segunda Enseñ. 2: 278. (1896)
Web links