[*] Spathe surrounding or subtending the spadix; flowers naked, i.e. without perianth.

1. Arisæma. Flowers monœcious or diœcious, covering only the base of the spadix.

2. Peltandra. Flowers monœcious, covering the spadix; anthers above, ovaries below.

3. Calla. Flowers perfect (at least the lower ones), covering the whole of the short spadix. Spathe open and spreading.

[*][*] Spathe surrounding the spadix in n. 4, none or imperfect in the rest; flowers with a calyx or perianth and perfect, covering the whole spadix.

4. Symplocarpus. Spadix globular, in a fleshy shell-shaped spathe. Stemless.

5. Orontium. Spadix narrow, naked, terminating the terete scape.

6. Acorus. Spadix cylindrical, borne on the side of a leaf-like scape.

1. ARISÆ̀MA, Martius. Indian Turnip. Dragon Arum.

Spathe convolute below and mostly arched above. Flowers monœcious or by abortion diœcious, covering only the base of the spadix, which is elongated and naked above. Floral envelopes none. Sterile flowers above the fertile, each of a cluster of almost sessile 2–4-celled anthers, opening by pores or chinks at the top. Fertile flowers consisting each of a 1-celled ovary, tipped with a depressed stigma, and containing 5 or 6 orthotropous ovules erect from the base of the cell; in fruit a 1–few-seeded scarlet berry. Embryo in the axis of albumen.—Low perennial herbs, with a tuberous rootstock or corm, sending up a simple scape sheathed with the petioles of the simple or compound veiny leaves. (Name from ἀρίς, a kind of arum, and αἷμα, blood, from the spotted leaves of some species.)

1. A. triphýllum, Torr. (Indian Turnip.) Leaves mostly 2, divided into 3 elliptical-ovate pointed leaflets; spadix mostly diœcious, club-shaped, obtuse, much shorter than the spathe, which is flattened and incurved-hooded at the ovate-lanceolate, pointed summit.—Rich woods, N. Scotia to Fla., west to Minn. and E. Kan. May.—Corm turnip-shaped, wrinkled, farinaceous, with an intensely acrid juice; spathe with the petioles and sheaths green, or often variegated with dark purple and whitish stripes or spots.

2. A. Dracóntium, Schott. (Green Dragon. Dragon-root.) Leaf usually solitary, pedately divided into 7–11 oblong-lanceolate pointed leaflets; spadix often androgynous, tapering to a long and slender point beyond the oblong and convolute pointed greenish spathe.—Low grounds, N. Eng. to Fla., west to Minn., E. Kan., and Tex. June.—Corms clustered; petiole 1–2° long, much longer than the peduncle.

2. PELTÁNDRA, Raf. Arrow Arum.

1. P. undulàta, Raf. Root of thick tufted fibres; scape 1–1½° high, about equalling the leaves; basal lobes of the leaves rather long and often acutish; spathe convolute throughout, wavy on the margin, mostly green, 4–7´ long; sterile portion of the spadix several times longer than the pistillate; ovules several; fruit green; seeds 1–3. (P. Virginica, Kunth, and most authors.)—Shallow water, New Eng. to Fla., west to Mich. and Ind. June.

2. P. álba, Raf. Rootstock tuberous, covered with thick-fleshy roots and propagating by offshoots; lobes of the leaves mostly short and broad, obtuse; spathe 3–4´ long, the blade broader, acuminate, somewhat expanded, white; sterile part of the spadix scarcely longer than the pistillate; ovules and seeds solitary; berry scarlet, 5–6´´ long. (P. Virginica, Schott. Xanthosoma sagittifolia, Chapm., not Schott. Caladium glaucum, Ell. Arum Virginicum, L., in part?)—Marshes, S. Va.(?) and N. C. to Fla.

3. CÁLLA, L. Water Arum.

Spathe open and spreading, ovate (abruptly pointed, the upper surface white), persistent. Spadix oblong, entirely covered with flowers; the lower perfect and 6-androus; the upper often of stamens only. Floral envelopes none. Filaments slender; anthers 2-celled, opening lengthwise. Ovary 1-celled, with 5–9 erect anatropous ovules; stigma almost sessile. Berries (red) distinct, few-seeded. Seeds with a conspicuous rhaphe and an embryo nearly the length of the hard albumen.—A low perennial herb, growing in cold bogs, with a long creeping rootstock, bearing heart-shaped long-petioled leaves, and solitary scapes. (An ancient name, of unknown meaning.)

1. C. palústris, L.—Cold bogs, N. Scotia to N. J., west to Mich. and Minn., and northward. June.—Seeds surrounded with jelly. (Eu.)

4. SYMPLOCÁRPUS, Salisb. Skunk Cabbage.

1. S. fœ̀tidus, Salisb. Leaves ovate, cordate, becoming 1–2° long, short-petioled; spathe spotted and striped with purple and yellowish-green, ovate, incurved; fruit (in autumn) 2–3´ in diam., in decay shedding the bulblet-like seeds, which are 4–6´´ long.—Bogs and moist grounds, N. Scotia to N. C., west to Minn. and Iowa.

5. ORÓNTIUM, L., Golden-club.

Spathe incomplete and distant, merely a leaf-sheath investing the lower part of the slender scape, and bearing a small and imperfect bract-like blade. Flowers crowded all over the narrow spadix, perfect; the lower with 6 concave sepals and 6 stamens; the upper ones with 4. Filaments flattened; anthers 2-celled, opening obliquely lengthwise. Ovary 1-celled, with an anatropous ovule; stigma sessile, entire. Fruit a green utricle. Seed without albumen. Embryo thick and fleshy, "with a large concealed cavity at the summit, the plumule curved in a groove on the outside." (Torr.)—An aquatic perennial, with a deep rootstock, long-petioled and entire oblong and nerved floating leaves, and the spadix terminating the elongated scape; its rather club-shaped emersed apex as thick as the spadix. (Origin of the name obscure.)

1. O. aquáticum, L.—Ponds, Mass. to Fla. May.

6. ÁCORUS, L. Sweet Flag. Calamus.

Spadix cylindrical, lateral, sessile, emerging from the side of a simple 2-edged scape which resembles the leaves, densely covered with perfect flowers. Sepals 6, concave. Stamens 6; filaments linear; anthers kidney-shaped, 1-celled, opening across. Ovary 2–3-celled, with several pendulous orthotropous ovules in each cell; stigma minute. Fruit at length dry, gelatinous inside, 1–few-seeded. Embryo in the axis of albumen.—Pungent aromatic plants, especially the thick creeping rootstocks (calamus of the shops), which send up 2-edged sword-like leaves, and scapes somewhat like them, bearing the spadix on one edge; the upper and more foliaceous prolongation sometimes considered as a kind of open spathe. (Ἄκορας, the ancient name, of no known meaning.)

1. A. Cálamus, L. Scape leaf-like and prolonged far beyond the (yellowish-green) spadix.—Margins of rivulets, swamps, etc., N. Scotia to Fla., west to Minn., Iowa, and E. Kan.

Order 124. LEMNÀCEÆ. (Duckweed Family.)

1. Spirodela. Frond 7–11-nerved, with several rootlets.

2. Lemna. Frond 1–5-nerved, with a single rootlet.

3. Wolffia. Frond thick, very minute (¼–{2/3}´ broad), without rootlets.

1. SPIRODÈLA, Schleiden.

Anther-cells bilocellate by a vertical partition and longitudinally dehiscent. Ovules 2. Frond 7–11-nerved or more; rootlets several, with axile vascular tissue. Otherwise as Lemna. (From σπεῖρα, a cord, and δῆλος, evident.)

1. S. polyrrhìza, Schleid. Fronds round-obovate (2–4´´ long), thick, purple and rather convex beneath, dark green above, palmately (mostly 7-) nerved. (Lemna polyrrhiza, L.)—Very common in ponds and pools, throughout N. Am., but very rarely found in flower or fruit. (Eu.)

2. LÉMNA, L. Duckweed. Duck's-meat.

Flowers produced from a cleft in the margin of the frond, usually three together surrounded by a spathe; two of them staminate, consisting of a stamen only; the other pistillate, of a simple pistil; the whole therefore imitating a single diandrous flower. Ster. Fl. Filament slender; anther 2-celled, didymous; the cells dehiscent transversely; pollen-grains large, spherical, muricate. Fert. Fl. Ovary 1-celled; style and truncate or funnel-shaped stigma simple. Ovules and seeds 1–7.—Fronds 1–5-nerved, producing a single rootlet beneath (which is destitute of vascular tissue), proliferous from a cleft in the margin toward the base, and at length stipitate; the tissue abounding with bundles of rhaphides. (An old Greek name of uncertain meaning.)

[*] Ovule solitary, orthotropous or nearly so; frond 1–3-nerved, thin.

[+] Fronds oblong, stalked at base, remaining connected.

1. L. trisúlca, L. Fronds oblong to oblong-lanceolate (6–9´´ long), attenuate at base into a slender stalk, denticulate at the tip, very obscurely 3-nerved, often without rootlets, usually several series of offshoots remaining connected; spathe sac-like; seeds ovate, amphitropous, with small round operculum.—Ponds and springy places, N. Scotia to N. J., west to the Pacific. (Eu.)

[+][+] Fronds oblong to elliptical or round-ovate, sessile, soon separating.

2. L. Valdiviàna, Philippi. Fronds elliptic-oblong, small (about 1´´ long), rather thick, usually somewhat falcate, obscurely 1-nerved; spathe broad-reniform; utricle long-ovate, pointed by the long style; seed orthotropous, oblong, with a prominent acute operculum. (L. Torreyi, Austin.)—Pools, N. J. and southward, westward across the continent. (S. Am.)

4. L. mìnor, L. Fronds round- to elliptic-obovate (1–2½´´ in diameter), rather thick, very obscurely 3-nerved; spathe sac-like; utricle short-urn-shaped, tipped with a short style; seed oblong-obovate, amphitropous, with prominent rounded operculum.—Stagnant waters, throughout N. Am. (Eu.)

[*][*] Ovules 2–7, anatropous; fronds very thick and spongy, flat above, very obscurely 5-nerved (1½–3´´ long).

5. L. gíbba, L. Fronds obovate-elliptic to nearly orbicular, almost hemispherical, soon separating; bract sac-like.—Mo. (?) to Ariz. and Calif.

3. WÓLFFIA, Horkel.

Flowers central, bursting through the upper surface of the globular (or in some foreign ones flat) and loosely cellular frond, only 2; one consisting of a single stamen with a 1-celled 2-valved anther; the other of a globular ovary, tipped with a very short style and a depressed stigma. Ovule orthotropous, rather oblique in the cell. Utricle spherical. Albumen thin.—Fronds rootless, proliferous from a cleft or funnel-shaped opening at the base, the offspring soon detached; no rhaphides.—The simplest and smallest of flowering plants, from ¼–{2/3}´´ long (an African and Cuban species much larger), floating as little grains on the water. (Named for John Fred. Wolff, who wrote on Lemna in 1801.)

1. W. Columbiàna, Karsten. Globose or globular, {1/3}–{2/3}´´ long, very loosely cellular, light green all over, not dotted; stomata 1–6; the opening at the base circular and with a thin border.—Floating rather beneath the surface of stagnant waters, Conn. to N. J., west to Minn. and La.

2. W. Brasiliénsis, Weddell. Oblong, smaller and more densely cellular, flattish and deep green with many stomata above, tumid and pale below, brown-dotted all over, anterior edge sharp, opening at base circular.—Growing with the last, but floating on the surface.

Order 125. ALISMÀCEÆ. (Water-Plantain Family.)

Marsh herbs, with scape-like stems, sheathing leaves, and perfect or monœcious or diœcious flowers; perianth of 3 herbaceous persistent sepals and as many (often conspicuous) white deciduous petals, which are imbricate or involute in bud; stamens 6 or more, included; ovaries numerous, distinct, 1-celled and mostly 1-ovuled, becoming achenes in fruit (in our genera); seeds erect; campylotropous.—Roots fibrous; leaves radical, petiolate and strongly nerved with transverse veinlets, the earlier sometimes without blade; flowers long-pedicellate, mostly verticillate, in a loose raceme or panicle, with lanceolate scarious bracts slightly connate at base.

1. Alisma. Flowers perfect, usually 6-androus. Carpels flattened, in one whorl.

2. Sagittaria. Flowers mostly unisexual. Stamens rarely few. Carpels flattened, in dense heads, winged.

3. Echinodorus. Flowers perfect. Stamens 6 or more. Carpels capitate, turgid and ribbed, often beaked.

Flowers perfect. Petals involute in the bud. Stamens definite, mostly 6. Ovaries many in a simple circle on a flattened receptacle, forming flattened coriaceous achenes, which are dilated and 2–3-keeled on the back.—Roots fibrous. Leaves all from the root, several-ribbed, with connected veinlets. Scape with whorled panicled branches. Flowers small, white or pale rose-color. (The Greek name; of uncertain derivation.)

1. A. Plantàgo, L. Perennial by a stout proliferous corm; leaves long-petioled, ovate, oblong, or lanceolate or even linear, acute, mostly rounded or heart shaped at base, 3–9-nerved; panicle loose, compound, many-flowered (1–2° long); carpels obliquely obovate, forming an obtusely triangular whorl in fruit.—Shallow water and ditches, across the continent. Very variable as to foliage, but the leaves usually more broadly cordate-ovate than in Old World forms (var. Americànum, R. & S.); when growing under water thinner and narrowly lanceolate. (Eu., etc.)

2. SAGITTÀRIA, L. Arrow-head.

Flowers monœcious, or often diœcious in n. 1 and 4, and polygamous in n. 7. Petals imbricated in the bud. Stamens indefinite, rarely few. Ovaries many, crowded in a spherical or somewhat triangular depressed head on a globular receptacle, in fruit forming flat membranaceous winged achenes.—Marsh or aquatic, mostly perennial, stoloniferous herbs, with milky juice and fibrous roots; the scapes sheathed at base by the bases of the long cellular petioles, of which the primary ones, and sometimes all, are flattened, nerved, and destitute of any proper blade (i.e. are phyllodia); when present the blade is arrow-shaped or lanceolate, nerved and with cross-veinlets as in Alisma. Flowers produced all summer, whorled in threes, with membranous bracts; the sterile above. (Name from sagitta, an arrow, from the prevalent form of the leaves.)

§ 1. SAGITTARIA proper. Flowers monœcious, with the lower whorls pistillate, or diœcious; stamens few or numerous, covering the receptacle; sepals spreading or reflexed in fruit.

[*] Filaments numerous, narrow, as long as or longer than the linear-oblong anthers; bracts 3, distinct; fruiting heads larger.

Var. pubéscens, Engelm. Upper part of petiole and scape and especially the orbicular-ovate obtuse bracts and sepals pubescent or woolly; beak of fruit horizontal.—N. J. and Penn. to Ga.

Var. (?) grácilis, Engelm. Lobes of the sagittate leaves very narrowly linear (½–2´´ wide); achene narrowly cuneate-obovate (2´´ long), the beak long, stout, and strongly recurved, the sides usually strongly 1–3-crested. (S. cristata, Engelm.?)—Mass. to western N. Y.; Iowa.

2. S. lancifòlia, L. Scape 2–5° high, with several of the lower whorls fertile; leaves lanceolate or lance-oblong, rarely linear, all with a tapering base, thick or coriaceous (6–18´ long and on a long and stout petiole, never sagittate), the nerves mostly arising from the very thick midrib; bracts ovate, acute or acuminate; pedicels slender, the fertile scarcely shorter than the sterile ones; filaments pubescent; achenes falcate, winged on the back, pointed with an incurved beak.—Swamps, Md. to Ky., Mo., and southward. (W. Ind.)

[*][*] Filaments very short, with enlarged mostly glandular base; anthers ovate or short-oblong; fruiting heads small; bracts more or less connate; leaves very rarely sagittate.

3. S. heterophýlla, Pursh. Scape weak (3´–2° high), at length procumbent; leaves lanceolate or lance-oval, entire, or with one or two narrow basal sagittate appendages; bracts roundish, obtuse; flowers of the lowest whorl fertile and almost sessile; the sterile on long pedicels; filaments glandular-pubescent; achenes narrowly obovate with a long erect beak.—N. Eng to Fla., west to Minn. and Mo. Varies as to foliage, the leaves being broad (var. ellíptica, Engelm.), or rigid and narrowly lanceolate with stout petioles (var. rígida, Engelm.), or nearly linear (var. angustifòlia, Engelm.)

4. S. gramínea, Michx. Scape 3´–2° high; phyllodia flat, mostly broadly linear, acuminate; leaves ovate-lanceolate to linear, on long slender petioles, sometimes reduced to the petiole merely; bracts rather obtuse; whorls of flowers often few, all staminate or the lower fertile; pedicels slender, spreading, nearly equal; filaments 15–20, glandular-pubescent; achene small (½´´ long), narrowly obovate, almost beakless, winged on the back, flat and scarcely costate on the sides.—N. Eng. to Minn., south to the Gulf; very variable.

5. S. tères, Watson. Phyllodia terete, very acutely attenuate upward, 3–12´ long, very rarely bearing a narrow blade; scape ½–1½° high; bracts connate at base; pedicels in 1–3 whorls, all very slender and spreading, 1 or 2 fruiting, ½–1´ long; filaments 12, dilated, pubescent; achene obovate, 1´´ long, with an erect beak, the margins and sides crenately several-crested.—In shallow water, S. New Eng. to N. J. (Hyannis, Mass., Deane; Wading River, L. I., Miller; barrens of N. J., Torrey.) Phyllodia usually very strongly nodose. (Addendum)—Sagittaria teres has been collected also at Brewster, Mass. (Farlow).

Var. (?) gracíllima, Watson. Scape and the almost or wholly bladeless leaves very slender and greatly elongated (2–4° long, 1´´ wide); pedicels all elongated, in usually distant whorls, the lower pistillate, slender and spreading; fruit unknown. (S. natans, Engelm. in Torr. Bull. ix. 4.)—In deep water of streams in E. Mass. (Hitchings, Boott, C. E. Faxon, etc.) Wholly submerged, only 1 or 2 flowers appearing at a time, floating on the surface. The fruit, maturing under water, has not yet been collected.

§ 2. LOPHIOCÁRPUS. Fertile flowers perfect; stamens 9–15, at the base of the receptacle; sepals erect and embracing the fruit.

7. S. calycìna, Engelm. Scape weak (3–9´ high), at length mostly procumbent; usually only the lowest whorl fertile, with pedicels as long as those of the sterile flowers, recurved in fruit; bracts orbicular, obtuse or rarely pointed; filaments slightly rough, as long as the anthers; achenes obovate with a short horizontal style; leaves broadly halberd-shaped, obtuse or acutish, with wide spreading lobes, often wider than long, or lanceolate or sometimes reduced to linear phyllodia.—Maine to Del., west to Wisc., Mo., and Tex. Quite variable, several forms being enumerated, as var. spongiòsa, with spongy texture and bladeless submerged leaves, eastward; and westward, var. flùitans, with lance-linear floating leaves.

3. ECHINÓDORUS, Richard.

Flowers perfect. Petals imbricated in the bud. Stamens 6–21 or more. Ovaries several or many, imbricated in a head, forming thick and ribbed achenes in fruit, often beaked with a projecting persistent style.—Mostly annuals, with the habit of Sagittaria, the naked stems sparingly branched or simple, and the flowers on rather short pedicels, in whorls of 3–6 or more. Fl. summer and autumn. (Name from ἐχινώδης, prickly, or from ἐχῖνος, and δορός a leathern bottle, applied to the ovary, which is in most species armed with the persistent style, so as to form a sort of prickly head of fruit.)

1. E. párvulus, Engelm. Scapes 1–3´ high; shoots often creeping and proliferous; leaves lanceolate or spatulate, acute (½–1½´ long, including the petiole); umbel single, 2–8-flowered; pedicels reflexed in fruit; flower 3´´ broad; stamens 9; styles much shorter than the ovary; achenes beakless, obtusely few-ribbed.—In mud, Mass. to Mich. and E. Minn., south to Fla. and Tex. (S. Am.)

2. E. rostràtus, Engelm. Scape erect, 3´–2° high, longer than the leaves; leaves broadly ovate, cordate or truncate at base, obtuse (the blade 1–3´ long); umbel proliferous, in a branched panicle; flower 5´´ broad; stamens 12; styles longer than the ovary; achenes beaked, acutely many-ribbed.—Swamps and ditches, Ill. to Fla., Mo., and Tex.—A low form (var. lanceolàtus, Engelm.) has the leaves lanceolate with an acute base. Ill., Mo.

3. E. radìcans, Engelm. Stems or scape prostrate, creeping (2–4° long), proliferous, bearing many whorls of flowers; leaves somewhat truncately broadly heart-shaped, obtuse (2–8´ broad), long-petioled; flowers 6–9´´ broad; stamens about 21; styles shorter than the ovary; achenes short-beaked, the keeled back denticulate.—Swamps, Ill. to N. C. and Fla., west to Mo. and Tex.

Marsh or mostly immersed aquatic herbs, with stems jointed and leafy or (in Triglochin) naked and scape-like, leaves sheathing at base or stipulate, and flowers perfect or unisexual, often spathaceous, with perianth of 4 or 6 herbaceous distinct valvate segments, or membranous and tubular or cup-shaped, or none. Stamens 1, 2, 4 or 6, with extrorse anthers. Ovaries 1–6, distinct or more or less coherent, 1-celled, usually 1-ovuled, in fruit follicular or capsular or an indehiscent berry or utricle.

Suborder I. Juncagineæ. Marsh plants, with terete bladeless leaves; flowers perfect, spicate or racemose, with herbaceous 6- (rarely 3-) lobed perianth; carpels 3 or 6, more or less united, separating at maturity. Seeds anatropous; embryo straight.

1. Triglochin. Ovaries 3–6, united until maturity. Leaves radical. Flowers bractless, in a spike-like raceme terminating a jointless scape.

2. Scheuchzeria. Ovaries 3, nearly distinct, at length divergent. Flowers bracteate in a loose raceme upon a leafy stem.

Suborder II. Naiadeæ. Immersed aquatics, with flat leaves; ovaries solitary or distinct, 1-ovuled.

[+] Flowers perfect, spiked or clustered; anthers 4 or 2, sessile; leaves alternate.

3. Potamogeton. Spike peduncled. Sepals 4, herbaceous. Anthers 4. Ovaries 4, sessile.

4. Ruppia. Flowers on an enclosed spadix, at length long-exserted, without perianth. Anther-cells 4, distinct. Ovaries 4, becoming stipitate.

[+][+] Flowers monœcious or diœcious, axillary, naked, monandrous; leaves opposite (alternate in n. 6).

5. Zannichellia. Monœcious. Pistils (2–5) from a cup-shaped involucre or sheath.

6. Zostera. Pistils and stamens alternate in 2 vertical rows on the inner side of a leaf-like enclosed spadix. Stigmas 2, linear. Stem creeping.

7. Naias. Diœcious; pistil solitary, naked. Stamen enclosed in a membranous spathe. Stems floating, with opposite or ternate leaves.

1. TRIGLÒCHIN, L. Arrow-grass.

Sepals and petals nearly alike (greenish), ovate, concave, deciduous. Stamens 3–6; anthers oval, on very short filaments. Pistils united into a 3–6-celled compound ovary; stigmas sessile; ovules solitary. Capsule splitting when ripe into 3–6 carpels, which separate from a persistent central axis.—Perennials, with rush-like, fleshy leaves, below sheathing the base of the wand-like naked and jointless scape. Flowers small, in a spiked raceme, bractless. (Name composed of τρεῖς, three, and γλωχίν, point, from the three points of the ripe fruit in n. 1 when dehiscent.)

[*] Fruit of 3 carpels.

1. T. palústris, L. Scape (6–18´ high) and leaves slender; sepals and stamens 6; fruit linear-club-shaped; carpels when ripe separating from below upward, leaving a triangular axis, awl-pointed at base.—Marshes, western N. Y. to Ill., Minn., and westward. Aug. (Eu., Asia, etc.)

2. T. striàta, Ruiz & Pav. Scape (6–12´ high) and leaves slender; flowers very small; sepals and stamens 3; fruit globose-triangular, or when dry 3-lobed. (T. triandra, Michx.)—Sea-shore, Md. to Fla. (S. Am., etc.)

3. T. marítima, L. Scape (1–3° high) and leaves thickish, fleshy; fruit ovate or oblong, acutish; carpels rounded at base and slightly grooved on the back, the edges acute.—Salt-marshes along the coast, Lab. to N. J., and in saline places in the interior across the continent. (Eu., Asia, etc.)

2. SCHEUCHZÈRIA, L.

Sepals and petals oblong, spreading, nearly alike (greenish-yellow), but the latter narrower, persistent. Stamens 6; anthers linear. Ovaries 3, globular, slightly united at base, 2–3 ovuled, bearing flat sessile stigmas, in fruit forming 3 diverging and inflated 1–2 seeded pods, opening along the inside.—A low bog-herb, with a creeping jointed rootstock, tapering into the ascending simple stem, which is zigzag, partly sheathed by the bases of the grass-like conduplicate leaves, and terminated by a loose raceme of a few flowers, with sheathing bracts; leaves tubular at the apex. (Named for John and John Jacob Scheuchzer, distinguished Swiss botanists early in the 18th century.)

1. S. palústris, L.—Peat-bogs, N. Brunswick to N. J., westward across the continent. June. (Eu., Asia.)

3. POTAMOGÈTON, Tourn. Pondweed.

Flowers perfect. Sepals 4, rounded, valvate in the bud. Stamens 4, opposite the sepals; anthers nearly sessile, 2-celled. Ovaries 4 (rarely only one), with an ascending campylotropous ovule; stigma sessile or on a short style. Fruit drupe-like when fresh, more or less compressed; endocarp (nutlet) crustaceous. Embryo hooked, annular, or cochleate, the radicular end pointing downward.—Herbs of fresh, or one in brackish, ponds and streams, with jointed mostly rooting stems, and 2-ranked leaves, which are usually alternate or imperfectly opposite; the submersed ones pellucid, the floating ones often dilated and of a firmer texture. Stipules membranous, more or less united and sheathing. Spikes sheathed by the stipules in the bud, mostly raised on a peduncle to the surface of the water. (An ancient name, composed of ποταμός, a river, and γείτων, a neighbor, from the place of growth.)—By fruit, the full-grown fresh or macerated fruit is intended; by nutlet, that with the fleshy outer portion or epicarp removed. All except n. 19 flower in summer; the month mentioned indicates the time of ripening of the fruit.

§ 1. Leaves of two sorts; floating ones more or less coriaceous, with a dilated petioled blade, different in form from the thinner submersed ones.

[*] Submersed leaves reduced to narrowly grass-like or filiform sessile phyllodia.

[+] Stems rather stout; stipules free; spikes all emersed, cylindrical and densely fruited; fruits fleshy and turgid, obliquely obovate.

2. P. Oakesiànus, Robbins. Stem more slender, much branched; floating leaves smaller (1–1½´ long), ovate- or oblong-elliptical, obtuse, fewer-(17–23-) nerved; lowest submersed ones almost capillary (only ¼–½´´ wide), continuing through the flowering season; spikes shorter (¾–1´ long), on peduncles much thicker than the stem; fruit smaller and more acute; sides of the turgid nutlet not at all impressed; curvature of the embryo nearly circular, its apex directed to a point above its base.—Ponds, and especially pools and stagnant ditches, Mass. to N. J.; also Anticosti. Aug.

3. P. Pennsylvánicus, Cham. Stems compressed, often simple from the creeping rootstocks; floating leaves chiefly opposite (1–3½´ long), 11–17-nerved, oblong, tapering into a short petiole, the lower gradually narrowing and passing into the submersed ones, which are very numerous and approximate, 2-ranked, linear (2–5´ long, and 1–2½´´ wide), 5–7-nerved, the lateral nerves slender and nearly marginal, the space within the inner nerves coarsely cellular-reticulated; stipules very obtuse; spikes numerous, about the length of the thickened peduncle; fruit round-obovate, flattish, 3-keeled when dry; nutlet distinctly impressed on the sides; curvature of the embryo transversely oval. (P. Claytonii, Tuckerm.)—Still or flowing water, N. Brunswick to S. C., west to N. Ind. and Minn. July, Aug.

[+][+] Like the preceding section, but all the parts small, slender and delicate, only the fertile plants producing floating leaves; spikes very small and few-flowered; propagated by autumn buds.

4. P. Vasèyi, Robbins. Very delicate; stem almost capillary; floating leaves obovate (3–5´´ long) and about the length of their filiform petioles, with 5 nerves deeply impressed beneath, cross-veins distinct; submersed leaves filiform-linear, very attenuate (1–2´ long, {1/8}–¼´´ wide) and acute; stipules not adnate, scarious, long, acute; spikes all emersed, few, interrupted-oblong, 3–5-flowered, on a thickish peduncle; fruit oblique, round-obovate ({2/3}´´ long), compressed, slightly sharp-margined, tipped with a distinct recurved style, the sides impressed and face acute; upper portion of the embryo circularly incurved, its apex transverse to the fruit.—Canada and N. Eng.; also Ill. The fruiting form, with floating leaves, rare; the submerged form apparently much more abundant.

5. P. lateràlis, Morong. Stem filiform, branching; floating leaves elliptical (4–6´´ long by 2´´ wide), with 5–7 nerves deeply impressed beneath, tapering at base into a somewhat dilated petiole shorter than the blade; submersed leaves linear, acute (1–3´ long by ¼–½´´ wide), 1–3-nerved, the mid-nerve with fine veins or cellular reticulations on each side, bi-glandular at base; stipules short; peduncles with a very peculiar lateral appearance, widely spreading at maturity, sometimes even recurved, often thicker than the stem; spikes often interrupted (2–4-flowered); fruit obliquely obovate (hardly 1´´ long), the back much curved, with two fine grooves upon it; embryo oval in its curve, the apex nearly touching the base.—Mass. and Mich.; rare. Undeveloped specimens resemble P. pusillus.

6. P. Spiríllus, Tuckerm. Floating leaves oval to lance-oblong and lanceolate (the largest 10´´ long, 4´´ wide), usually obtuse, about equalling the rather dilated petioles, with 5–many nerves beneath deeply impressed; upper submersed leaves either with or without a lance-oblong or broad-linear proper blade; the numerous lower ones narrow-linear, tapering toward the obtuse apex (¾–1½´ long, ¼–{2/3}´´ wide); stipules early lacerate; submersed flowers usually solitary on very short erect peduncles; fruit with the back either winged and with 4–5 distinct teeth or wingless and entire; embryo coiled 1¾ turns.—Rivers, and even far up small streams, N. Eng. to Va., west to Mich. and Mo. June–Aug.—Stem less slender than in the next.

7. P. hýbridus, Michx. Floating leaves oval to lance-oblong (the largest 10´´ long, 6´´ wide), often acute, longer than the filiform petioles, with about 5–7 nerves beneath deeply impressed; submersed leaves very numerous, almost setaceous (1–3´ long, very rarely ½´´ wide); stipules obtuse; emersed spikes 4–7´´ long; submersed spikes 1–4-flowered, their peduncles (of their own length) frequently recurved; fruit minute, about 8-toothed on the margin; embryo coiled 1½ turns.—Shallow stagnant waters, N. Brunswick to Fla., west to Mich., Mo., and N. Mex. June–Aug.

[*][*] Submersed leaves lanceolate, rarely oval or linear, membranaceous; spikes dense, many-flowered, on stout peduncles.

8. P. ruféscens, Schrad. Stem simple; floating leaves (often wanting) 2–5´ long, rather thin, wedge-oblanceolate, narrowed into a short petiole, 11–17-nerved; submersed leaves almost sessile, lanceolate and lance-oblong, smooth on the margin, fewer-nerved; stipules broad, hyaline, obtuse, upper ones acuminate; spike 1–2´ long, often somewhat compound; fruit obovate, lenticular, pitted when immature, with an acute margin and pointed with the rather long style; embryo incompletely annular.—In streams or ponds, N. Brunswick to N. J., west to Minn. and Tex. Aug., Sept. (Eu.)

9. P. flùitans, Roth. Stem often branching below; floating leaves thinnish, lance-oblong or long-elliptical, often acute, long-petioled, 17–23-nerved; submersed leaves very long (3–12´, by 2–12´´ wide), lanceolate and lance-linear, 7–15-nerved, coarsely reticulated; peduncles somewhat thickened upward; fruit obliquely obovate, obscurely 3-keeled when fresh, and distinctly so when dry, the middle one winged above and sometimes with 3–5 shallow indentations; the rounded slightly curved face surmounted by the short style; nutlet with the sides scarcely impressed; upper part of the embryo circularly in-curved. (P. lonchites, Tuckerm.)—In streams or rarely in ponds, N. Brunswick to N. J., west to Minn. and Iowa. Aug., Sept. (Eu.)

11. P. amplifòlius, Tuckerm. Stems simple, of very variable length; floating leaves (sometimes wanting) large, oblong or lance-ovate, sometimes slightly cordate at base, abruptly acutish, 30–50-nerved, on rather long petioles; submersed leaves often very large (reaching 7´ by 2´), lanceolate or oval, acute at each end, usually much recurved, undulate, mostly on short petioles; stipules very long and tapering to a point, soon becoming loose; peduncles thickened upward, in deep water much elongated; fruit very large (over 2´´ long), rather obliquely obovate, 3-keeled, with a broad stout beak; nutlet slightly impressed on the sides; upper part of the embryo curved into a ring.—Ponds and rivers, N. Eng. to N. J., west to Minn. and Kan. Aug., Sept.

12. P. Illinoénsis, Morong. Stem stout, branching towards the summit; floating leaves opposite, oval or ovate (2–5´ long by 1½–2´ broad), 19–25-nerved, rounded or subcordate at base, with a short blunt point at apex, on short petioles, submersed leaves rather few, oblong-elliptical, acute at each end, usually ample (largest 8´ by 1½´); stipules coarse, obtuse, strongly bicarinate (2´ long); peduncles often clustered at the summit (2–4´ long), thickening upward; fruit roundish-obovate (1¾–2´´ long), 3-keeled on the back, middle keel prominent; nutlet flattened and slightly impressed on the sides, obtuse or pointed at base; apex of embryo directed transversely inward.—Streams and ditches, western N. Y. to Ill., Iowa, and Minn. Very near the last.

13. P. heterophýllus, Schreb. Stem slender, very branching below; floating leaves mostly thin, variable, but with a short blunt point, 9–15-nerved, usually 1–2´ long and 6–9´´ wide; submersed ones usually lanceolate or linear-lanceolate, acuminate or cuspidate, narrowed toward the base, about 7-nerved on the stem and 3-nerved on the branches; upper ones petioled, lower sessile; stipules obtuse, loose; peduncles somewhat thickened upward; fruit small, roundish, compressed, scarcely keeled; embryo annular above. (P. gramineus, Fries.)—Still or flowing water, common. Varies exceedingly in its submersed leaves, peduncles, etc.; the var. graminifòlius (Fries), growing in rapid streams, with stems much elongated and less branched, and the flaccid submersed leaves 2–7´ long by 2–10´´ wide.

Var. (?) myriophýllus, Robbins. Sending up from running rootstocks many short repeatedly dichotomous and densely leafy stems; fertile stems very slender; floating leaves small, delicate, lance-oblong, on long filiform petioles; submersed stem-leaves larger, early perishing; those of the branches (deep-green) linear-oblanceolate, very small (¾–1´ long), acute, sometimes minutely serrulate; spike slender, loosely-flowered, much shorter than the thickened peduncle.—Apponaug Pond, R. I., without fruit.

§ 2. Leaves all submersed and similar, mostly sessile, membranaceous and dilated, lanceolate, oblong, or oval; stipules obtuse, becoming loose.

14. P. lùcens, L. Stem thick, branching, sometimes very large; leaves more or less petioled, oval or lanceolate, mucronate, often rough serrulate, frequently shining; peduncles often elongated; fruit roundish and compressed, with obtuse margins, slightly keeled; embryo circularly incurved above.—Ponds, N. Eng. to Fla., west to the Pacific. Aug., Sept. (Eu.)

Var. (?) Connecticuténsis, Robbins. Stem flexuous; leaves all submersed, nearly sessile, lanceolate, acuminate, crisped, not shining nor serrulate; fruit larger, distinctly keeled; nutlet thick and hard.—Lake Saltonstall, East Haven, Conn.

15. P. prælóngus, Wulf. Stem very long, branching, flexuous; leaves lance-oblong or lanceolate (sometimes 7´ long), half-clasping, obtuse with a boat-shaped cavity at the extremity, thence splitting on pressure; stipules scarious, very obtuse; spikes rather loose-flowered; peduncles very long (sometimes reaching 20´); fruit obliquely obovate, compressed, sharply keeled when dry; style terminating the nearly straight face; curve of the embryo oval and longitudinal.—Ponds and large rivers, N. Scotia to Mass., west to Minn. and Iowa. Sept., Oct.—Stem white; foliage bright green. (Eu.)

16. P. perfoliàtus, L. Stem branching; leaves orbicular, ovate or lanceolate from a cordate-clasping base, usually obtuse and often minutely serrulate; peduncles short, cylindrical; fruit irregularly obovate, obtusely margined; embryo incurved in an oval.—Ponds and slow streams, common. N. Scotia to Fla., west to Minn. and Iowa. Sept., Oct. (Eu.)

Var. lanceolàtus, Robbins. Larger; leaves long-lanceolate from a cordate clasping base and acuminate, wavy, 3–4½´ long; peduncles thickened upward.—Same range as the species, and extending west to the Pacific.

17. P. críspus, L. Stem compressed; leaves linear-oblong, half-clasping, obtuse, serrulate, crisped-wavy, 3-nerved; fruit long-beaked; upper portion of the embryo incurved in a large circle.—Flowing and stagnant waters, Mass. to N. J. and Va., west to western N. Y. June, July. (Eu.)

18. P. Mýsticus, Morong. Stem very slender and irregularly branching, nearly filiform (1–3° high); leaves oblong-linear (½–1½´ long by 2–3´´ wide), 5–7-nerved, finely undulate and entire, obtuse or bluntly pointed, abruptly narrowing at base, sessile or partly clasping; spikes few, capitate (4–6-flowered). on erect peduncles (1–2´ long); fruit (immature) obovate, small (hardly ¾´´ long), obscurely 3-keeled on the back, a little beaked by the slender recurved style.—Mystic Pond, Medford, Mass.

§ 3. Leaves all submersed and similar, mostly membranaceous and sessile, linear or setaceous.

[*] Stipules free from the sheathing base of the leaf.

20. P. Híllii, Morong. Stem slender, widely branching, flattish; leaves linear, acute (1–2½´ long by ½–1¼´´ wide), 3-nerved, the lateral nerves delicate and near the margin; stipules whitish, striate, obtuse (3–5´´ long); spikes capitate (3–6-fruited), on short spreading or recurved peduncles; fruit as in the last.—Mich. and western N. Y.

21. P. obtusifòlius, Mertens & Koch. Stem flattened, very branching; leaves linear, tapering toward the base, obtuse and mucronate or very acute, 3- (rarely 5-) nerved; stipules elongated, very obtuse; spike ovate, continuous, 5–8-flowered, about the length of the peduncle; fruit oval, apiculate with the style, not keeled when fresh, upper portion of embryo coiled inward and lying transverse to the fruit.—Slow streams and ponds, Canada and N. Eng. to western N. Y. and Mich. Sept., Oct. (Eu.)

22. P. pauciflòrus, Pursh. Stem filiform, flattish and very branching; leaves narrowly linear (1–2´ long and seldom ½´´ wide), acute, obscurely 3-nerved; stipules obtuse; spikes capitate, 1–4- (usually 2-) flowered, on short club-shaped peduncles; fruit roundish-lenticular; the back more or less crested; upper portion of the embryo incurved in a circle.—Still or stagnant waters, N. Brunswick to Ga., Iowa, Minn., and westward.

Var. Niagarénsis, Gray. Stem often longer (1–3°); leaves larger (1½–3½´ long by 1´´ wide or less), 3–5-nerved at base, very acute and mucronate, narrowed to the subpetiolate base. (P. Niagarensis, Tuckerm.)—Running water, Great Lakes to S. C.; also in Cal.

23. P. pusíllus, L. Stem slender, flattish or nearly cylindrical, often very branching; leaves narrow- or setaceous-linear, acuminate, acute or subacute, 1–3-nerved, furnished with translucent glands on each side at the base; stipules at first obtuse; spikes interrupted or capitate, 2–8-flowered, on rather long peduncles; fruit obliquely elliptical, scarcely keeled; apex of embryo incurved and directed obliquely downward.—Pools and ditches, N. Scotia to N. J., west to Minn. and Mo., and westward.—Leaves sometimes almost setaceous (var. tenuissimus, Koch).

Var. polyphýllus, Morong. Dwarf form (3–5´ high), divaricately branching from the base, very leafy throughout; leaves very obtuse, not cuspidate, 3-nerved; non-flowering but abundantly provided with propagating buds which are formed on the thickened and hardened ends of the branches and closely invested by imbricated leaves.—In a shallow pool, S. Natick, Mass.

24. P. mucronàtus, Schrad. Resembling P. pusillus, but stem less branching; leaves broader (almost 1´´ wide), often 5-nerved; spikes interrupted. (P. pusillus, var. major, Fries.)—N. Brunswick to western N. Y., Mich., and Minn. July. (Eu.)

25. P. gemmíparus, Robbins. Stem filiform, branching, terete, varying greatly in height; leaves hair-like, sometimes not as broad as the stem, often with no apparent midrib, tapering to the finest point (1–3´ long), bi-glandular at base; stipules ½–1´ long; spikes few (3–6-flowered), interrupted, on long filiform peduncles; propagating buds very numerous; fruit like that of P. pusillus, very rare. (P. pusillus, var.? gemmiparus, Robbins.)—Slow-moving streams and still water, Mass. Aug., Sept.

[*][*] Stipules united with the sheathing base of the leaf.

27. P. pectinàtus, L. Stem filiform, repeatedly dichotomous; leaves very narrowly linear, attenuate to the apex, 1-nerved with a few transverse veins; spikes interrupted, on long filiform peduncles; fruit obliquely broad-obovate, compressed, bluntly keeled; shell of nutlet very thick; embryo spirally incurved.—N. Brunswick to Fla., westward across the continent. Aug.–Oct. (Eu.)

28. P. marìnus, L. Resembling narrow-leaved forms of the last species, low and very leafy; peduncles much elongated; fruit much smaller (1´´ long) and thinner, round-obovate, not keeled upon the rounded back, tipped with the broad sessile stigma; embryo annular.—Western N. Y., Ill., Mich., and southward. Probably the range of this species is much more extensive than indicated, as it has been confounded with P. pectinatus.

29. P. Robbínsii, Oakes. Stem ascending from a creeping base, rigid, very branching, invested by the bases of the leaves and stipules; leaves crowded in two ranks, recurved-spreading, narrow-lanceolate or linear (3–5´ long and 2–3´´ wide), acuminate, ciliate-serrulate with translucent teeth, many-nerved; stipules obtuse when young, their nerves soon becoming bristles; spikes numerous, loosely few-flowered, on short peduncles; fruit oblong-obovate (2´´ long), keeled with a broadish wing, acutely beaked; embryo stout, ovally annular.—In ponds and slow streams, N. Brunswick to N. J., the N. shore of L. Superior, and far westward.

4. RÚPPIA, L. Ditch-grass.

Flowers perfect, 2 or more approximated on a slender spadix, which is at first enclosed in the sheathing spathe-like base of a leaf, entirely destitute of floral envelopes, consisting of 2 sessile stamens, each with 2 large and separate anther-cells, and 4 small sessile ovaries, with solitary campylotropous suspended ovules; stigma sessile, depressed. Fruit small obliquely ovate pointed drupes, each raised on a slender stalk which appears after flowering; the spadix itself also then raised on an elongated thread-form peduncle. Embryo ovoid, with a short and pointed plumule from the upper end, by the side of the short cotyledon.—Marine herbs, growing under water, with long and thread-like forking stems, and slender almost capillary alternate leaves, sheathing at the base. Flowers rising to the surface at the time of expansion. (Dedicated to H. B. Ruppius, a German botanical author of the early part of the 18th century.)

1. R. marítima, L. Leaves linear-capillary; nut ovate, obliquely erect, 1½´´ long; fruiting peduncles capillary (3–6´ long); stipes 1–12´´ long.—Shallow bays, along the entire coast; also occasionally in saline places in the interior. (Eu., Asia, etc.)

Flowers monœcious, sessile, naked, usually both kinds from the same axil; the sterile consisting of a single stamen, with a slender filament bearing a 2–4-celled anther; the fertile of 2–5 (usually 4) sessile pistils in the same cup-shaped involucre, forming obliquely oblong nutlets in fruit, beaked with a short style, which is tipped by an obliquely disk-shaped or somewhat 2-lobed stigma. Seed orthotropous, suspended, straight. Cotyledon taper, bent and coiled.—Slender branching herbs, growing under water, with mostly opposite long and linear thread-form entire leaves, and sheathing membranous stipules. (Named in honor of Zannichelli, a Venetian botanist.)

1. Z. palústris, L. Style at least half as long as the fruit, which is flattish, somewhat incurved, even, or occasionally more or less toothed on the back (not wing-margined in our plant), nearly sessile; or, in var. pedunculàta, both the cluster and the separate fruits evidently peduncled.—Ponds and slow streams, throughout N. America, but not common. July. (Eu., Asia.)

6. ZOSTÈRA, L. Grass-wrack. Eel-grass.

Flowers monœcious; the two kinds naked and sessile and alternately arranged in two rows on the midrib of one side of a linear leaf-like spadix, which is hidden in a long and sheath-like base of a leaf (spathe); the sterile flowers consisting of single ovate or oval 1-celled sessile anthers, as large as the ovaries, and containing a tuft of threads in place of ordinary pollen; the fertile of single ovate-oblong ovaries attached near their apex, tapering upward into an awl-shaped style, and containing a pendulous orthotropous ovule; stigmas 2, long and bristle-form, deciduous. Utricle bursting irregularly, enclosing an oblong longitudinally ribbed seed (or nutlet). Embryo short and thick (proper cotyledon almost obsolete), with an open chink or cleft its whole length, from which protrudes a doubly curved slender plumule.—Grass-like marine herbs, growing wholly under water, from a jointed creeping stem or rootstock, sheathed by the bases of the very long and linear, obtuse, entire, grass-like, ribbon-shaped leaves (whence the name, from ζωστήρ, a band).

1. Z. marìna, L. Leaves obscurely 3–5-nerved.—Common in shoal water of bays along the coast, from Newf. to Fla. (Eu.)

7. NÀIAS, L. Naiad.

Flowers diœcious or monœcious, axillary, solitary and sessile; the sterile consisting of a single stamen enclosed in a little membranous spathe; anther at first nearly sessile, the filament at length elongated. Fertile flowers consisting of a single ovary tapering into a short style; stigmas 2–4, awl-shaped; ovule erect, anatropous. Fruit a little seed-like nutlet, enclosed in a loose and separable membranous epicarp. Embryo straight, the radicular end downward.—Slender branching herbs, growing under water, with opposite and linear leaves, somewhat crowded into whorls, spinulose-toothed, sessile and dilated at base. Flowers very small, solitary, but often clustered with the branch-leaves in the axils; in summer. (Ναιάς, a water-nymph.)

Var. grácilis, Morong. Internodes long (1–3´) and nearly naked, with only a few teeth above; leaves very narrow, the dilated base also toothed; fruit smaller.—Canoga marshes, western N. Y.; also in Fla.

Var. recurvàta, Dudley. Stems short, inclined to be dichotomously branched, recurved-spreading; leaves usually recurved, the teeth prominent, the dilated base with a projecting tooth each side.—Cayuga marshes, N. Y.

2. N. fléxilis, Rostk. & Schmidt. Stems usually very slender; leaves very narrowly linear (½–1´ long), very minutely serrulate; fruit 1½´´ long, narrowly oblong; seeds lance-oval, smooth and shining.—Ponds and slow streams, N. Scotia to S. C., Iowa and Minn. Teeth on the margins of the leaves 1-celled. (Eu.)—Var. robústa, Morong. Stem stout, few-leaved, sparsely branching, elongated; leaves flat, abruptly acute.—E. Mass., Mich., and Tex.

3. N. Índica, Cham., var. gracíllima, A. Br. Branches alternate; leaves very narrowly linear, nearly capillary, straight, serrate, the rounded lobes of the sheathing base spinulose-ciliate; fruit linear, impressed-dotted between the numerous ribs.—Mass. to Penn., west to Ind. and Mo. Teeth of 3 cells each.

Order 127. ERIOCAÙLEÆ. (Pipewort Family.)

Aquatic or marsh herbs, stemless or short-stemmed, with a tuft of fibrous roots, a cluster of linear and often loosely cellular grass-like leaves, and naked scapes sheathed at the base, bearing dense heads of monœcious or rarely diœcious small 2–3-merous flowers, each in the axil of a scarious bract; the perianth double or rarely simple, chaffy; anthers introrse; the fruit a 2–3-celled 2–3-seeded capsule; seeds pendulous, orthotropous; embryo at the apex of mealy albumen.—Chiefly tropical plants, a few in northern temperate regions.

1. Eriocaulon. Perianth double, the inner (corolla) tubular-funnel-form in the staminate flowers; stamens twice as many as its lobes (4). Anthers 2-celled.

2. Pæpalanthus. Perianth as in the last; stamens only as many as the corolla-lobes (3). Anthers 2-celled.

3. Lachnocaulon. Perianth simple, of 3 sepals. Stamens 3, monadelphous below. Anthers 1-celled.

1. ERIOCAÙLON, L. Pipewort.

1. E. decangulàre, L. Leaves obtuse, varying from linear-lanceolate to linear-awl-shaped, rather rigid; scapes 10–12-ribbed (1–3° high); head hemispherical, becoming globular (2–7´´ wide); scales of the involucre acutish, straw-color or light brown; chaff (bracts among the flowers) pointed.—Pine-barren swamps, N. J. to Fla. July–Sept.

2. E. gnaphalòdes, Michx. Leaves spreading (2–5´ long), grassy-awl-shaped, rigid, or when submersed thin and pellucid, tapering gradually to a sharp point, mostly shorter than the sheath of the 10-ribbed scape; scales of the involucre very obtuse, turning lead-color; chaff obtuse.—Pine-barren swamps, N. J. to Fla.

3. E. septangulàre, Withering. Leaves short (1–3´ long), awl-shaped, pellucid, soft and very cellular; scape 4–7-striate, slender, 2–6´ high, or when submersed becoming 1–6° long, according to the depth of the water; chaff acutish; head 2–3´´ broad; the bracts, chaff, etc., lead-color, except the white coarse beard.—In ponds or along their borders, Newf. to N. J., west to Ind., Mich., and Minn. July, Aug. (Eu.)

2. PÆPALÁNTHUS, Martius.

Stamens as many as the (often involute) lobes of the funnel-form corolla of the sterile flowers, and opposite them, commonly 3, and the flower ternary throughout. Otherwise nearly as in Eriocaulon. (Name from παιπάλη, dust or flour, and ἄνθος, flower, from the meal-like down or scurf of the heads and flowers of many South American species.)

1. P. flavídulus, Kunth. Tufted, stemless; leaves bristle-awl-shaped (1´ long); scapes very slender, simple, minutely pubescent (6–12´ high), 5-angled; bracts of the involucre oblong, pale straw-color, those among the flowers mostly obsolete; perianth glabrous; sepals and petals of the fertile flowers linear-lanceolate, scarious-white.—Low pine-barrens, S. Va. to Fla.

3. LACHNOCAÙLON, Kunth. Hairy Pipewort.