Page:Manual of the New Zealand Flora.djvu/789

Potamogeton.] minute areolation; stipules very long and conspicuous, 3–5 in., free, acuminate. Submerged leaves wanting or if present few and reduced to long and narrow phyllodes without any lamina. Peduncles stout, 2–4 in. long, bearing a dense-flowered spike 1½–2 in. long. Perianth-segments broadly rhomboidal. Fruit ⅙ in. long, turgid, obliquely ovoid, keeled on the back when dry, beak short.—''Hook. f. Fl. Nov. Zeal. i. 236; Handb. N.Z. Fl. 278; Benth. Fl. Austral.'' vii. 170 ''(in part); A. Bennett in Journ. Bot.'' xxv. (1887) 177.

2. P. polygonifolius, ''Pourr. in Mem. Acad. Toul.'' iii. (1788) 325.—Stem creeping at the base, long or short, simple or sparingly branched. Floating leaves on long petioles; lamina 1–3 in. long, elliptic-oblong to lanceolate, acute or obtuse, rounded or subcordate or acute at the base, not plicate, thinly coriaceous; stipules much shorter than in P. natans, 1–1½ in. long. Submerged leaves linear-lanceolate, acute. Peduncles variable in length, rather slender; spike dense-flowered, ¾–1½ in. long. Perianth-segments transversely elliptic. Fruit small, reddish, $1⁄12$–$1⁄10$ in. long, blunt and rounded on the back, not keeled, beak very short.—Kirk in Trans. N.Z. Inst. iii. (1871) 165.

3. P. Cheesemanii, ''A. Bennett in Journ. Bot.'' xxi. (1883) 66.—Stems slender, striated, long or short, simple or branched. Upper leaves alternate or opposite, long-petioled; lamina ¾–1¾ in. long, elliptic-oblong to oblong or lanceolate, obtuse, rounded at the base, coriaceous, 10–16-nerved with numerous cross-veins and minute areolation; stipules broad, subacute. Submerged leaves numerous, usually alternate but sometimes opposite, shortly petioled, 2–4 in. long, ¼–¾ in. broad, oblong-lanceolate to lanceolate or linear, very thin and membranous, translucent, 5–12-nerved with rather distant cross-veins, margins often undulate or crisped, not denticulate. Peduncles variable in length, rather slender; spike dense, ½–¾ in.