S. lenticularis, Poir. Encyc. Suppl. v. 103.—Stems slender, in very wet places 6–18 in. long, elongated and much branched, putting out a small tuft of leaves at each node, often forming large floating masses; in drier situations shorter and stouter, much more sparingly branched, 2–6 in. high. Leaves 1–3 in. long, filiform in floating specimens, stouter in terrestrial ones. Peduncles shorter or longer than the leaves, slender, usually 1 from each tuft of leaves, each bearing a single terminal spikelet. Spikelets variable in size, ⅛–¼ in. long, oblong or oblong-ovoid, obtuse, pale-green; bract (lowest glume) usually longer than the spikelet. Glumes ovate, acute, concave but scarcely keeled, green, sometimes stained with chestnut-brown. Hypogynous bristles wanting. Stamens 2 or 3. Style-branches 2. Nut three-quarters the length of the glume, obovoid, biconvex, tipped by a minute point, slightly narrowed at the base, smooth, pale.—Benth. Fl. Austral. vii. 326. S. fluitans var. terrestris, Benth. l.c. 325. S. crassiusculus, Cheesem. in Trans. N.Z. Inst. xv. (1883) 300 (not of Hook. f.). Isolepis lenticularis, R. Br. Prodr. 222; Hook. f. Fl. Tasm. ii. 86, t. 145d. Isolepis fluitans, Kirk in Trans. N.Z. Inst. iii. (1871) 166 (not of R. Br.).

North Island: Auckland—North Cape Peninsula, T. F. C.; Waikato River, Lakes Whangape, Waikare, and Waihi, Kirk! T. F. C.; Lake Taupo, Kirk! swamps near the base of Ruapehu, Berggren! H. Tryon! A. Hamilton! Petrie! Sea-level to 2500 ft. December–March.

Also in eastern Australia and Tasmania, and very closely allied to the widely spread S. fluitans, L.

S. basilaris, C. B. Clarke, MS.—A dwarf species forming dense tufts 1–3 in. diam. Stems very short, ⅛–½ in. long, much branched at the base, leafy. Leaves far overtopping the stems, ½–1½ in. long, sheathing at the base, semiterete above, channelled in front, convex at the back, tip obtuse. Spikelets terminal, solitary or rarely 2 together, concealed amongst the leaves and sometimes almost radical, 1/10–⅙ in. long ovoid, obtuse, pale-green; bract long, leafy. Glumes broadly ovate, obtuse, with broad white membranous margins, and a stout green midrib which is usually produced into a thick excurrent tip. Stamens 2. Style-branches 2. Nut orbicular-obovoid, not angled nor trigonous, slightly compressed, obtuse, smooth but not polished, minutely dotted, light-or dark-brown.—Isolepis basilaris, Hook. f. Handb. N.Z. Fl. 302. I. novæ-zealandiæ, Col. in Trans. N.Z. Inst. xxi. (1889) 102.

North Island: Hawke's Bay—Mud-banks by the Ngaruroro River, Colenso! Kirk! Petrie! South Island: Wesbland—Jackson's, Teremakau River, Petrie! Otago—Not uncommon in the middle portion of the Clutha Valley, Roxburgh, Beaumont, Spear-grass Flat, Petrie! Pomahaka, Kirk! Sea-level to 2000 ft. November–March.

A curious little plant, in its usual state easily distinguished by the very short stems with the spikelets concealed by the leaves. But some forms have the stems more developed, and are then easily taken for small varieties of S. aucklandicus, which, however, has a very different nut.

S. aucklandicus, Boeck. in Linnæa, xxxvi. (1869–70) 491.—Forming compact grassy patches 2–6 in. diam. or more. Stems numerous, densely crowded, much branched at the base, stout or slender, striate, leafy at the base, 1–6 in. high. Leaves 2–6, equalling or longer than the stems, stout or slender, usually more or less coriaceous and rigid but sometimes almost flaccid, semiterete, convex on the back, grooved in front, tips obtuse. Spikelet solitary or rarely 2, small, 1/12–⅛ in. long, broadly ovoid, varying in colour from dark chestnut-brown to pale whitish-green; bract very long, leafy, obtuse at the tip. Glumes few, ovate, obtuse, concave, often with a thick excurrent keel, very variable in colour. Stamens 3 or 2. Style-branches 3. Nut elliptic-ovoid, compressed, trigonous with the angles rounded, white or pale-yellow, smooth but not polished.—Isolepis aucklandica, Hook. f. Fl. Antarct. i. 88, t. 50; Handb. N.Z. Fl. 302. Isolepis cartilaginea var. rigida, Berggr. in Minnesk. Fisiog. Sallsk. Lund. (1877) n. viii. 23. I. alpina, Hook. f. Fl. Tasm. ii. 86 (in part).

Var. subcucullata, C. B. Clarke, MS.—Much more slender and diffuse. Stems weak, almost filiform; spikelet pale, solitary, 3–6-flowered. Glumes slightly hooded at the tip.—Isolepis subcucullata, Berggren l.c. 22, t. 5, f. 16–20.

North Island: Ruahine Mountains, Colenso! Rangipo Desert, Petrie! Ruapehu, Rev. F. H. Spencer. South Island: Not uncommon in mountain-swamps throughout. Stewart Island, Auckland and Campbell Islands: Plentiful in moist places, descending to sea-level. December–March.

A variable plant. The typical state can be recognised without; much difficulty by the dense leafy habit, the leaves frequently overtopping the stems, by the small usually solitary spikelets, and pale elliptic-ovoid nut. But lowland states, with a more slender and less leafy habit, are difficult to separate from S. cernuus. Other forms approach very closely to S. antarcticus. According to Mr C. B. Clarke, the species is also found in Tasmania and Amsterdam Island.

S. cernuus, Vahl. Enum. ii. 245.—Stems densely tufted, very slender, quite glabrous, 2–6 in. high, rarely more. Leaves setaceous, 1–3 near the base of the stem and shorter than it. Spikelets solitary or 2–3 together, ovoid or oblong-ovoid, 1/10–⅕ in. long; bract variable in length, usually exceeding the spikelets, continuous with the stem so that the spikelets appear to be lateral. Glumes 6–15, broadly ovate, concave or obscurely keeled, obtuse or with a short page 774point, green or chestnut-brown. Stamens 3, rarely 2 or 1. Style-branches 3, long, linear. Nut about half the length of the glume, trigonous, obovoid, obtuse, minutely apiculate, not longitudinally ribbed, the surface appearing to be minutely reticulate from the numerous subquadrate cells.—S. Savii, Sebast. and Mauri, Prodr. Fl. Rom. 22. S. riparius, Poir. Encycl. Suppl. v. 103; Benth. Fl. Austral. vii. 327. Isolepis riparia, R. Br. Prodr. 222; Hook. f. Fl. Tasm. ii. 89, t. 145c; Handb. N.Z. Fl. 302. I. setacea, Hook. f. Fl. Nov. Zel. i. 271, in part (not of R. Br.). I. setosa, Raoul, Choix, 40.

North and South Islands, Stewart Island, Chatham Islands, Auckland and Campbell Islands: Abundant throughout. Sea-level to 2000 ft. November–February.

Nearly cosmopolitan, being found in all temperate and tropical countries except south-eastern Asia. In New Zealand there are two principal forms: one, which is usually littoral, has the stems rather stiff, the spikelets usually solitary and often chestnut-brown, and the nut broadly obovoid; the other is more slender, the spikelets are paler, and the nut much smaller, more elliptical, and more acutely trigonous.

S. antarcticus, Linn. Mant. ii. 181.—Densely tufted, very variable in size, sometimes ½–1½ in. high, stout, rigid, cartilaginous; at other times taller and more slender, 3–6 in. high or more. Leaves 1 or several at the base of the stem and shorter than it, obtuse at the tip, rigid and coriaceous in the smaller forms, softer and more grassy in the larger ones. Heads solitary, terminal, of 1–4 spikelets in the small stout forms, of 3–9 in the larger ones; bracts ¼–1 in. long, usually far exceeding the head. Spikelets rather stout, ovoid-oblong, ⅛–⅕ in. long, many-flowered. Glumes broadly ovate, boat-shaped with a prominent keel, obtuse or the keel produced into a short point, often rigid and coriaceous, pale whitish-yellow with a conspicuous dark chestnut-brown spot; sides broad, marked with prominent curved lines; back often curved. Hypogynous scales wanting. Stamens 3 or 2, rarely 1. Style-branches 3. Nut rather more than half as long as the glume, elliptic-ovoid, trigonous, acute, minutely punctate, white to yellow, sometimes ultimately almost black.—C. B. Clarke in Fl. Cap. vii. 223. S. cartilagineus, Poir. Encycl. Suppl. v. 103; Benth. Fl. Austral. vii. 328. S. ebenocarpus, Kirk in Trans. N.Z. Inst. xvii. (1885) 224. Isolepis cartilaginea, R. Br. Prodr. 222; Hook f. Fl. Nov. Zel. i. 271; Fl. Tasm. ii. 88, t. 145; Handb. N.Z. Fl. 302.

North Island: Hawke's Bay—Colenso! A. Hamilton! Wellington—Karioi, Kaiwarawara, Kirk! South Island: Nelson—Cape Farewell, Kirk! Canterbury—Burnham, Kirk! Springfield, T. F. C. Otago—Catlin's River, Petrie! Lake Wakatipu, Kirk! Bluff Hill, Kirk! Stewart Island: Port Pegasus, Petrie! Kirk! Sea-level to 2000 ft. November–March.

Also in extratropical Australia, South Africa, and St. Helena.

S. inundatus, Poir. Encycl. Suppl. v. 103.—Very variable in size and habit of growth. Stems 2–12 in. high, often small, slender and filiform, at other times stouter and taller, and resembling small states of S. sulcatus and S. prolifer. Leaves 1 or rarely 2 at the base of the stem, or reduced to a short and broad sheath. Heads solitary, terminal, of 2–15 crowded spikelets, often proliferous and putting out 1 or several short or long branches ending in a smaller head of spikelets; bract very variable in length. Spikelets 1/10–¼ in. long ovate or ovate-oblong, subacute, pale or dark chestnut-brown, many-flowered. Glumes broadly ovate, concave or keeled at the back, obtuse or subacute, the sides usually more or less stained or striate with dark red-brown, the keel usually pale. Stamen 1. Style-branches 3, long, linear. Nut about half the length of the glume, oblong-obovoid, equally and conspicuously trigonous, with a small conical point, not longitudinally ribbed, white, smooth but not polished.—Benth. Fl. Austral. vii. 329. S. reticularis, Col. in Trans. N.Z. Inst. xviii. (1886) 277. Isolepis inundata, R. Br. Prodr. 222. I. prolifer, Hook. f. Handb. N.Z. Fl. 301; Fl. Tasm. ii. 87, t. 144 (not of R. Br.). I. setacea, Hook. f. Fl. Nov. Zel. i. 271, in part (not of R. Br.).

Var. major.—Stems tall and stout, 5–12 in. high, usually leafless. Spikelets more numerous, 6–15, densely compacted. Glumes obtuse. Approaches small forms of S. sulcatus, but is at once distinguished by the smaller acutely trigonous nut.

Var. gracillima.—Stems slender, often filiform, 2–6 in. long. Spikelets 2–6, flattened. Glumes often subacute.

North and South Islands, Stewart Island, Chatham Islands: Abundant throughout. Sea-level to 3000 ft. November–March.

As defined above, this varies so much in habit and other respects as to give rise to the suspicion that more species than one are included in it; but I have failed to find valid distinguishing characters. It extends through Australia to the Malay Archipelago, and is also abundant in temperate South America.

S. sulcatus, Thouars, Esquisse Fl. Trist. 36, t. 7; var. distig matosa, C. B. Clarke, MS.—Stems numerous, tufted, 8–16 in. high, stout, grooved when dry, leafless except a large purple or purplish-black sheath at the base. Heads solitary, terminal, of 6–20 densely packed spikelets, often proliferous and emitting 1 or several branches ending in a smaller head of spikelets; bract variable in length. Spikelets rather short, ⅛–¼ in. long, oblong, obtuse, many-flowered. Glumes broadly ovate, obtuse, concave, dark chestnut-brown with a green keel and pale margins. Hypogynous bristles wanting. Stamens usually 1. Style-branches 2, rarely 3, long, linear. Nut about half the length of the glume, obovoid, plano-convex, the convex side not keeled, smooth and polished, shining, white or pale yellowish-white.—Isolepis prolifer, Hook. f. Fl. Nov. Zel. i. 271, for the most part (not of R. Br., nor of Hook. f. Handb. N.Z. Fl. 301).

North and South Islands: Apparently common: Auckland—Hokianga, Berggren; Whangarei, H. Carse! vicinity of Auckland, Petrie! T. F. C.; Rotorua, Cartwright, Petrie! T. F. C.; Taupo, Kirk! Hawke's Bay—Norsewood, Colenso! Wellington—Murirnotu, Petrie! Canterbury—Styx River, Petrie! Sea-level to 2000 ft. November–March.

For the identification of this plant with the Tristan d'Acunha S. sulcatus I am indebted to Mr. C. B. Clarke, who, however, maintains it as a distinct, variety, characterized by the usually 2-fid style and plano-convex nut not keeled on the convex face. Large stout forms of S. inundatus approach it very closely, but in fruit are easily distinguished by the 3-fid style and acutely trigonous nut. S. prolifer, which has precisely the same habit of growth, can always be separated by the long linear spikelets, 3 stamens, and small acutely trigonous nut.

S. prolifer, Rottb. Descr. et Ic. 55, t. 17, f. 2.—Stems numerous, tufted. 1–2 ft. high or more, rather stout, striate when dry, leafless except a large purplish or purplish-black sheath at the base. Heads large, ½–1 in. diam., terminal, solitary, of very many (10–30) densely crowded spikelets, often proliferous and putting out 1 or several usually long branches terminating in a much smaller head of spikelets; bract shorter than the head, obtuse. Spikelets long and narrow, ⅕–½ in. long, linear or linear-oblong, cylindrical, obtuse, many-flowered. Glumes ovate, obtuse, concave, chestnut-brown with a paler keel and margins. Hypogynous bristles wanting. Stamens 3. Style-branches 3, long, linear. Nut rather small, less than half the length of the glume, elliptic-ovoid, acute, acutely trigonous, smooth, pale yellowish-brown or almost white.—Benth. Fl. Austral. vii. 330. Isolepis prolifer, R. Br. Prodr. 223. I. globosa, Buch, in Trans. N.Z. Inst. iii. (1871) 211.

North Island: Auckland—Bay of Islands, Kirk! Wellington—Karori, Evans Bay, and other localities in the vicinity of the City of Wellington, Buchanan! Kirk! Petrie! Wairarapa, Kirk! November–March.

Also in New South Wales, and abundant, in South Africa. Easily separated from S. sulcatus and large states of S. inundatus by the very numerous long and narrow spikelets, and flowers with 3 stamens.

S. nodosus, Rottb. Descr. et Ic. 52, t. 8, f. 3.—Rhizome short, stout, woody, creeping, ¼ in. diam. or more. Stems very numerous, closely packed, 1–3 ft. high, erect, rigid, terete or slightly compressed. Leaves wanting except 2 or 3 sheathing scales at the base of the stems. Head solitary, globose, brown, ⅓–⅔ in. diam., of very numerous densely crowded spikelets; bract ½–1½ in. long, rigid, erect, continuous with the stem, so that the head appears lateral. Spikelets ovoid, ⅕–⅙ in. long, many-flowered. Glumes broadly ovate, obtuse or obscurely mucronate, concave. Hypogynous bristles wanting. Stamens 3. Style-branches 3, linear. Nut less than ½ the length of the glume, obovoid, obtusely trigonous, the flat face next the glume, pale-brown, smooth and polished. —Benth. Fl. Austral. vii. 331. Isolepis nodosa, R. Br. page 777Prodr. 221; A. Rich. Fl. Nouv. Zel. 104; A. Cunn. Precur. n. 272; Raoul, Choix, 40; Hook. f. Fl. Nov. Zel. i. 270; Handb. N.Z. Fl. 301.

Kermadec Islands, North and South Islands, Stewart Island, Chatham Islands: Abundant throughout. Sea-level to 2000 ft. November–February.

Also found in Norfolk Island and Lord Howe Island, temperate Australia, extratropical South Africa, St. Helena and Amsterdam Islands, and temperate South America.

S. frondosus, Banks and Sol. ex Boeck. in Flora, lxi. (1878) 141.—Stout, rigid, harsh, yellow-green, 2–3 ft. high. Rhizome thick, woody, creeping, often many feet in length. Stems many along the rhizome, stout, erect, obtusely trigonous, leafy at the base. Leaves very numerous, spreading, often curved, rigidly coriaceous, channelled above, keeled beneath, gradually narrowed into long trigonous points, at the base expanded into broad membranous sheaths; margins and keel sharply denticulate. Inflorescence 3–9 in. long or more, of linear clusters of densely crowded sessile spikelets arranged in a spiral manner, around the upper part of the stem, each cluster subtended by a rigid linear bract similar to the leaves. Spikelets red-brown, almost globose, about ⅛ in. long, many-flowered. Glumes broadly ovate, obtuse, concave, shining, seriate. Hypogynous bristles wanting. Stamens 3; anthers with a long awn. Style-branches 3. Nut broadly obovoid, compressed, quite smooth.—Isolepis spiralis, A. Rich. Fl. Nouv. Zel. 105, t. 19; A. Cunn. Precur. n. 274; Raoul, Choix, 40. Desmoschœnus spiralis, Hook. f. Fl. Nov. Zel. i. 272; Handb. N.Z. Fl. 303. Anthophyllum Urvillei, Steud. Cyp. 160.

North and South Islands, Chatham Islands: Abundant on sand-dunes from the North Cape to Otago. Pingao. November–February.

The leaves were formerly used by the Maoris for making kits, and occasionally for cloaks, which were said to be very durable.

S. americanus, Pers. Syn. i. 68.—Rhizome creeping. Stems rather slender, 1–2 ft. high, acutely trigonous. Leaves 1–4, always shorter than the stem; sheaths long. Head small, of 1–4 closely compacted sessile spikelets; bract 1–2 in. long, erect, angular, continuous with the stem so that the head appears lateral. Spikelets broadly ovoid, ¼–⅓ in. long, dark-brown, many-flowered. Glumes broadly ovate, membranous, concave, tip emarginate with usually a short awn in the notch, margins scarious above. Hypogynous bristles 4–6, shorter than the nut. Stamens 3. Style-branches 2–3. Nut rather large, ⅔ the length of the glume, obovoid, plano-convex, pale-brown, smooth.—S. pungens, Vahl. Enum. ii. 255; Benth. Fl. Austral. vii. 333. S. triqueter, R. Br. Prodr. 223; Hook, f. Fl. Nov. Zel. i. 269; Handb. N.Z. Fl. 300 (not of Linn.). S. novæ-zealandiæ, Col. in Trans. N.Z. Inst. xviii. (1886) 277.

North and South Islands, Chatham Islands: Brackish-water swamps from Hokianga to Foveaux Strait, but often local. Inland at Roxburgh, Otago, Petrie! November–February.

Not uncommon in temperate Australia and Tasmania, North and South America, and southern Europe.

S. lacustris, Linn. Sp. Plant. 48.—Rhizome stout, creeping, with numerous perpendicular rootlets. Stems 2–6 ft. high, sometimes almost as thick as the finger, terete, spongy, glaucous. Leaves wanting, or the uppermost sheath with a very short flat lamina. Inflorescence a terminal simple or compound cymose umbel 2–4 in. across; rays few, stout, irregular; bract shorter than the umbel, continuous with the stem. Spikelets numerous, ovoid or oblong, ⅓ in. long, brownish, many-flowered. Glumes broadly ovate, membranous, concave, notched at the tip with a small point in the notch, margins fringed. Hypogynous bristles 5–6, linear, retrorsely scabrid, usually equalling the nut. Stamens 3. Style-branches 3 or 2. Nut more than half as long as the glume, obovoid, compressed, plano-convex, pale-brown, smooth.—A. Rich. Fl. Nouv. Zel. 103; A. Cunn. Precur. n. 275; Raoul, Choix, 40; Hook. f. Fl. Nov. Zel. i. 269; Handb. N.Z. Fl. 300; Benth. Fl. Austral. vii. 333.

North and South Islands: Margins of lakes and ponds from the North Cape southwards to the north of Otago and Okarito, common. Sea-level to 1500 ft. November–February.

Generally distributed in all temperate and warm countries, except South America.

S. maritimus, Linn. Sp. Plant. 74.—Rhizome woody, creeping, the nodes often dilated into hard tubers. Stems stout, sharply triangular, 1–3 ft. high or more. Leaves from near the base of the stem and often exceeding it, broad, flat, grassy. Inflorescence an irregular terminal umbel of few unequal rays, often contracted into a compact cluster; bracts 3–4, 3–9 in. long, similar to the leaves. Spikelets ½–¾ in. long, sessile or peduncled, ovoid or cylindric, brown, many-flowered. Glumes ovate, membranous, 2-lobed at the tip with a short intermediate awn, usually pubescent towards the tip. Hypogynous bristles 3–6, shorter than the nut, retrorsely scabrid. Stamens 3. Style-branches 3 or 2, long, linear. Nut less than one-half the length of the glume, broadly obovoid, compressed, flat on one side, convex or obtusely angled on the other, smooth and polished, brown when fully ripe.—Raoul, Choix, 40.; Hook.f. Fl. Nov. Zel. i. 269; Handb. N.Z. Fl. 300.

Var. fluviatilis, Torr. in Ann. Lyceum New York, iii. (1836) 324.—Taller and stouter, 3–6 ft. high. Leaves broader, ½ in. diam. or more; bracts longer. Umbel larger, more often compound; rays 3–9. Spikelets large, pale-brown. Style-branches 3. Nut narrower, oblong-obovoid, trigonous, conspicuously beaked, white or pale-brown, opaque, polished.—Benth. Fl. Austral. vii. 335. S. fluviatilis, Asa Gray, Man. Bot. U.S. 500.

Var. macrostachya, Michx. Fl. Bor. Amer. v. 32.—Umbels simple or compound. Spikelets large, sometimes over 1 in. long. Style-branches almost always 2. Nut large, broadly obovoid, flat on one side and obscurely angled on the other, white or pale-brown, opaque, not polished.—Asa Gray, Man. Bot. U.S. 500.

North and South Islands: The two varieties not uncommon in brackish-water swamps and on the banks of lakes and streams from the North Cape to Otago Harbour. November–February.

In the North Island var. fluviatilis extends inland along most of the larger rivers, ascending the Waikato as far as Lake Taupo. Var. macrostachya seems to be chiefly found in brackish-water swamps. Both varieties are abundant in North America, and also in Australia and Tasmania. According to Mr. C. B. Clarke, the typical form of the species has not yet been observed in either Australia or New Zealand.