436. Lloydia. - Flowers white, small, erect; nectary transverse; anthers erect; perianth spreading, persistent; stigma 3-angled; seeds angular above.

437. Colchicum. - Style 4; ovary 4-5-lobed; rootstock a corm; flowers like Crocus, autumnal, funnel-shaped; tube long; leaves several, radical; ovaries buried.

438. Narthecium. - Rhizome slender, creeping; flowers yellow; scape leafy; perianth 6-partite; capsule 3-celled; seeds appendaged.

439. Tofieldia. - Flowers greenish - white; perianth 6-partite; styles 3; stigmas 3; capsule septicidal.

440. Paris. - Leaves net-veined; rhizome stout; leaves in whorl, 4-5; flowers terminal; perianth 4-partite, in 2 whorls; styles 4; ovary 4-5-lobed.

Order 84., Juncaceae

441. Juncus. - Leaves round; plant smooth; perianth 6-fid, glumaceous; style simple; stigmas 3; capsule 3-celled; seeds many.

442. Luzula. - Plant tufted, hairy; leaves flat, grass-like; capsule 1-celled, 3-valved; seeds 3 at base.

Order 85. Typhaceae

443. Typha. - Plant monoecious; flowers in long cylindrical spikes; upper male, stamens united, surrounded by hairs; lower female.

444. Sparganium. - Plant monoecious; flowers in round heads; perianth-segments 3-4; stamens free; fruit dry.

Order 86. Araceae (Aroideae)

445. Arum. - Plant monoecious; leaves hastate; flowers in spadix, enclosed in spathe; perianth o; male flowers of 1 sessile 2-celled anther; spadix naked above.

446. Acorus. - Flowers bisexual on lateral spadix; perianth-segments 6; stamens 6.

Order 87. Lemnaceae

447. Lemna. -Aquatic, floating; stem and leaves none, frond with 1 or more roots; flowers unisexual, in spathe, from lateral slit in frond; stamens 1-2; anthers 2-celled.

448. Wolffia. - Plant rootless, aquatic, floating; no spathe; stamen 1; flowers from surface; anther 1-celled.

Order 88. Alismaceae

449. Alisma. - Leaves flat; flowers bisexual, in whorls; stamens 6; carpels numerous, free, in a ring; ovules solitary.

450. Echinodorus. - Flowers bisexual, in umbel or whorl; stamens 6; carpels numerous, free.

451. Elisma. - Leaves floating; flowers bisexual, sub-solitary; carpels numerous, free; stamens 6.

452. Sagittaria. - Plant monoecious; leaves erect, sagittate; flowers whorled; stamens many; carpels free.

453. Damasonium. - Leaves erect, 2; flowers bisexual, in whorls; stamens 6; carpels united below, star-like, spreading.

454. Butomus. - Leaves 3-angled; perianth-segments 6, rose-coloured; stamens 9; carpels 6, united below.

Order 89. Naiadaceae (Including Potamo-Getonaceae)

455. Triglochin. - Marsh plants; flowers without bracts; perianth-segments erect; stamens 6; anthers short; carpels free, 1-2-seeded; stigma downy.

456. Scheuchzeria. - Flowers with bracts; perianth-segments 6, deciduous, spreading; stamens 6; filaments and anthers long; stigmas feathery.

457. Potamogeton. - Flowers bisexual, in spikes; perianth-segments 4; anthers 4, sessile; styles o; drupes 4, sessile.

458. Ruppia. - Flowers bisexual, 2 together; perianth o; stamens 4; styles o; achenes 4, stalked.

459. Zannichellia. - Plant monoecious; flowers solitary, axillary; male flower: perianth o; 1 stamen; female flower: perianth bell-shaped; stigma peltate; nuts 2-5.

460. Zostera. - Marine plant; plant monoecious; stamens and pistils in slit of leaf; perianth o; stigmas 2; style 1; anther 1.

461. Naias. - Plant monoecious; flowers solitary, axillary, sheathed; perianth tubular; 1 stamen; stigmas 2-4.

Order 90. Eriocaulonaceae

462. Eriocaulon. - Plant monoecious; leaves radical; flowers in scaly head; perianth 4-6-fid; stamens 4-6; stigmas 2-; capsule 2-3-celled.

Order 91. Cyperaceae

463. Cyperus. - Flowers bisexual; spikelets many-flowered, flattened; glumes in 2 rows, deciduous, all flowering, keeled, many; fruit chestnut brown.

464. Eleocharis (Heleocharis). - Spikelet solitary, terminal, round in section; 1 of lowest glumes empty; bristles 3-6, included; nut compressed, crowned by style base.

465. Scirpus. - Spikelets in clusters, lateral; glumes overlapping, sub-equal; bristles o or 3-8, included; nut 3-angled.

466. Eriophorum. - Spikelets solitary or clustered, terminal; glumes sub-equal; bristles longer than glumes, silky; nut 3-angled.

467. Rhynchospora. - Spikelets round in section, in an ovoid head, few-flowered; glumes 6 or 7; bristles 6, slender; nut convex, beaked.

468. Schoenus. - Spikelets flattened, in 2 rows, 2-4-flowered; glumes 6-9, lower barren; bristles few or none; nut black, not beaked.

469. Cladium. - Spikelets round in section, few-flowered, in several crowded, compound cymes; glumes 5 or 6, lobed, lower empty; bristles o; nut blunt, with fleshy coat.

470. Kobresia. - Plant monoecious; spikelets 1-2-flowered; spikes close; upper flowers male, perianth o; lower flowers female, with perianth of 1 scale; fruit not enclosed in perigynium.

471. Carex. - Plant monoecious; male flowers above, female below, as a rule; spikelets many-flowered, in overlapping spikes, with glumes; female flowers enclosed in a bottle-shaped persistent perigynium; style 1; stigmas 2-3; male flowers of 3 stamens; perianth o; nut enclosed in perigynium.

Order 92. Graminaceae

472. Panicura. - Spike compound, spreading; spikelets flattened dorsally; glumes 4, unequal; pedicels of spikelets smooth or hairy.

473. Setaria. - Spike cylindrical, compound, interrupted below; spikelets with an involucre of bristles, in dense spike; glumes 4.

474. Spartina. - Spikes erect; spikelets laterally compressed, awnless; style long; glumes 3, unequal.

475. Leersia. - Spikelets laterally compressed, in loose panicle; glumes o; paleae 2, awnless, lower broader.

476. Phalaris. - Spike ovate; spikelets laterally compressed; glumes equal, boat-shaped, keeled, 6, third and fourth imperfect, not awned; stamens 3.