Polygonum decipiens R.Br.
P. serrulatum auct. non Lag. Gen. et Sp . . . 1816, 14.
P. prostratum A. Rich. Essai Fl. N.Z. 1832, 177 non R. Br. Prodr. 1810, 419.
P. minus Huds. var. decipiens (R. Br.) Hook. f. Handbk N.Z. Fl. 1864, 235.
Slender glab. to glabrate, eglandular, lax herb; stems slender, up to 6 dm. long, prostrate and rooting in basal part, then ascending, sparingly branched. Lvs on short petioles; lamina membr., pungent-tasting, 5-10-(15) × 1-3-(4) cm., lanceolate, acuminate, minutely serrulate; ochreae delicate, ± 1·5 cm. long, sparsely hairy, mouth obliquely truncate, ciliate; cilia (1)-2-(5) mm. long. Infl. of simple spikes (2)-3-5 cm. long on slender peduncles up to 10 mm. long. Fls ± 2 mm. diam., 2-3 per cluster; bracts narrow, truncate, ciliate. Tepals us. 5, oblong, glab., reddish to whitish; stamens us. 5, styles 2-branched. Fr. lenticular to subplano-convex, margined, ± 2 mm. long, including style base; dark blackish brown, ± glossy.
DIST.: N., S., Ch. Frequent to occ. by streamsides, swamp and bog margins from near North Cape to lat. 44°.
FL.- FT. 11-4. Also in Tasmania and Australia.
Hooker (Fl. N.Z. I, 1854, 216) accepted P. aviculare as indigenous to N.Z., citing specimens collected "Akaroa, Raoul. Ahuriri Colenso". In the Handbk N.Z. Fl., 1864, 236 he cites the same collections and adds various localities for var. dryandri. He says, " perhaps introduced into N.Z." and in the second part, 1867, 761, he places it in the list of naturalized spp. Kirk (T.N.Z.I. 2, 1870, 142) preferred "to regard it as indigenous". In T.N.Z.I. 4, 1872, 238-241, he argues at length for the nativity of the "typical" form.
W. T. L. Travers (T.N.Z.I. 1871, 336) considered it introduced, "Dr Hector and Mr Buchanan in particular both concur with me". Later (T.N.Z.I. 5, 1873, 310-314) Travers, in a detailed historical account, says: " We find that these plants are not mentioned by any collector before Raoul, who obtained the typical form at Akaroa and the Bay of Islands about 1840, whilst Lyall obtained the variety at Port Cooper, some eight or ten years later".
Kirk (T.N.Z.I. 5, 1873, 315-320) attempted to rebut Travers's arguments and states that the plant has "a decided preference for cultivated land, but found also in widely different situations, on mountains and in forests". I have seen it, but rarely, on much traversed tracks in open lowland forests.
P. aviculare is not mentioned by Raoul in his Choix 1846, nor by A. Cunningham in his Precursor 1838. Cheeseman (Man. N.Z. Fl. 1925, 398) says, "I should certainly have relegated it to the list of naturalized plants had it not been for the positive opinion expressed in favour of its nativity by the late Mr. Kirk". A number of different forms are now naturalized in N.Z.
