Persicaria sect. Echinocaulon

Stems usually scandent or, rarely, ascending or erect, simple or branched, with recurved prickles. Leaves: ocrea chartaceous or foliaceous, margins eciliate or ciliate; petiole, if present, rarely winged, not auriculate; blade without dark triangular or lunate blotch adaxially, broadly lanceolate or elliptic to triangular, base truncate to sagittate to cordate, margins entire or hastately lobed. Inflorescences terminal and axillary, spikelike, paniclelike, or capitate, uninterrupted or, rarely, interrupted proximally. Flowers homostylous, articulation swollen or not; perianth campanulate; tepals 4–5, connate 1/4–1/2 their length; stamens 5–8; styles deciduous, 2–3, included or, rarely, exserted, erect or spreading.

Distribution

e North America, South America, Asia, se Africa, e Australia.

Discussion

Species 21 (5 in the flora).

Selected References

Park, C. W. 1986. Nomenclatural typifications in Polygonum section Echinocaulon (Polygonaceae). Brittonia 38: 394–406.

Park, C. W. 1987. Flavonoid chemistry of Polygonum sect. Echinocaulon: A systematic survey. Syst. Bot. 12: 167–179.

Park, C. W. 1988. Taxonomy of Polygonum section Echinocaulon (Polygonaceae). Mem. New York Bot. Gard. 47: 1–82.

Lower Taxa

Persicaria arifolia, Persicaria bungeana, Persicaria meisneriana, Persicaria perfoliata, Persicaria sagittata

Key

1	Ocreae, at least some, foliaceous, green; perianths fleshy and blue in fruit	Persicaria perfoliata
1	Ocreae chartaceous, brownish; perianths not fleshy and blue in fruit	> 2
2	Ocreae margins truncate, ciliate with bristles 2-4 mm	Persicaria bungeana
2	Ocreae margins oblique, eciliate or ciliate with bristles to 2.5 mm	> 3
3	Leaf blades broadly hastate to hastate-cordate or triangular; tepals 4	Persicaria arifolia
3	Leaf blades linear-lanceolate to oblong; tepals 5	> 4
4	Peduncles usually glabrous, sometimes with retrorse prickles proximally; leaves petiolate; bases of leaf blades sagittate to cordate; stamens 8	Persicaria sagittata
4	Peduncles usually stipitate-glandular; leaves sessile or subsessile; bases of leaf blades cordate to truncate or cuneate; stamens 5	Persicaria meisneriana