Volume 14 > Part 1 > Year 2018 > Page 132 > Polygonaceae > Persicaria

5. Persicaria dichotoma (Blume) Masam.wfo-0001250573

Sci. Rep. Kanazawa Univ., Biol. 2: 82. 1954; K.L.Wilson, Kew Bull. 45(4): 634. 1990; Kantachot et al., Thai Forest Bull., Bot. 38: 137. 2010.—Polygonum dichotomum Blume, Bijdr. Fl. Ned. Ind. 11: 529. 1826; Backer & Bakh.f., Fl. Java 1: 223. 1963; P.H.Hô, Câyco Việtnam 1(2): 944. 1991; A.J.Li et al. in C.Y. Wu et al., Fl. China 5: 314. 2003; N.T.Do in Bân, Fl. Vietnam 11: 188. 2007.—Truellum dichotomum (Blume) Soják, Preslia 46(2): 145. 1974. Plate XIV: C.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Ascending herbs, up to 40 cm tall; stem and branches terete, prickles on nodes retrorse, (1–)1.5–2.5 mm long. Leaves with petioles 3–10(–25) mm long, glabrous or sometimes with sparse hispid hairs, without retrorse prickles; lamina (4.5–)5.5–8.5(–10.5) by 1–2.2(–2.7) cm, elliptic or ovate, entire on both surfaces, base cuneate or hastate, apex acute, margin entire with minute hispid hairs, primary vein glabrous on both surfaces; secondary veins 9–14-paired. Ocreae cylindrical, (1.5–)1.8–2.5(–2.8) cm long, scarious, glabrous, venation conspicuous, apex oblique, without ciliate hairs. Inflorescences terminal and axillary, spicate panicle, 7–13(–19) cm long, erect; inflorescence branches glabrous, except underneath side branches with glandular hairs; side branches (5–)8–12(–15) mm long, stout, cylindrical, dense-flowered; leafy bracts absent or 3.5–4.5(–5.5) by (0.3–)0.5–1 cm, elliptic or ovate, apex acute, margin entire. Flowers 2–3 in an ocreola; pedicels 2–2.5 mm long, glabrous; bracteoles 2.5–3 mm long; ocreolae incompletely enclosing rachis, 2–2.5(–3) mm long, glabrous, apex acute to acuminate, margin entire with hispid hairs, 0.2–0.5 mm long. Tepals 5, white or pink; lobes 1.5–2 by 1.2–1.8 mm, obovate-elliptic, apex obtuse, veins 4–5; tube (1.2–)1.5–2 mm long, glandular nectaries 5. Stamens 5, in a single whorl, filaments white, 1.2–1.8 mm long; anthers white. Styles 2, 0.6–1 mm long; stigmas capitate, white. Fruits lenticular, 2–2.5 by 1.8–2.1(–2.2) mm, shiny brown.

Thailand : NORTHERN: Chiang Mai, Chiang Rai; NORTH-EASTERN: Loei, Nong Khai, Sakon Nakhon; EASTERN: Chaiyaphum; PENINSULAR: Phatthalung.

Distribution : India, Sri Lanka, China, Taiwan, Laos, Vietnam, Peninsular Malaysia, Singapore, Java (type), the Philippines, Australia.

Ecology : Swampy areas, marshy places and rice fields, 200–1,200 m alt.

Vernacular : Phak phaeo nam (ผักแพวน้ำ).