Calyx of 6 sepals; the 3 outer herbaceous, sometimes united at base, spreading in fruit; the 3 inner larger, somewhat colored, enlarged after flowering (in fruit called _valves_) and convergent over the 3-angled achene, veiny, often bearing a grain-like tubercle on the back. Stamens 6. Styles 3; stigmas tufted. Embryo slightly curved lying along one side of the alb.u.men, slender.--Coa.r.s.e herbs, with small and homely (mostly green) flowers, which are crowded and commonly whorled in panicled racemes; the petioles somewhat sheathing at base. (The ancient Latin name; of unknown etymology.)

-- 1. LaPATHUM. (DOCK.) _Flowers perfect or monciously polygamous; herbage not sour or scarcely so; none of the leaves halberd-shaped.

(Flowering through the summer.)_

[*] _Perennials, 1--7 high, mostly with fusiform roots; valves not bearing bristles._

[+] _Valves (large, 3" broad or more, thin) all naked or one with a small grain._

R. PATIeNTIA, L. (PATIENCE DOCK.) A very tall species, with ovate-oblong and lanceolate leaves (broadest above the base), those from the root 2--3 long, and one of the heart-shaped nearly or quite entire valves (3" broad) bearing a small grain, or its midrib thickened at base.--N. Eng and N. Y. (Adv. from Eu.)

1. R. vensus, Pursh. Stems from running rootstocks, erect (1 high or less), with conspicuous dilated stipules; leaves on short but rather slender petioles, ovate or oblong to lanceolate (3--6'; long), acute or ac.u.minate, only the lowest obtuse at base; panicle nearly sessile, short, dense in fruit; valves entire, glandless, broadly cordate with a deep sinus, 9--12" in diameter, bright rose-color.--Sask. to central Mo. and Kan., and westward.

[+][+] _Valves smaller, one or more of them conspicuously grain-bearing._

[++] _Indigenous; leaves not wavy, none heart-shaped, except the lowest of n. 5._

2. R. Britannica, L. (GREAT WATER-DOCK.) Tall and stout (5--6 high); leaves oblong-lanceolate, rather acute at both ends, transversely veined, and with obscurely erose-crenulate margins (the lowest, including the petiole, 1--2 long, the middle rarely truncate or obscurely cordate at base); racemes upright in a large compound panicle, nearly leafless; whorls crowded; _pedicels capillary, nodding, about twice the length of the fruiting calyx; the valves...o...b..cular or round-ovate_, very obtuse, obscurely heart-shaped at base, _finely reticulated_, entire or repand-denticulate (2--3" broad), all grain-bearing. (R. orbiculatus, _Gray_.)--Wet places, N. Eng. to N. J., west to Minn, and Kan.

3. R. altissimus, Wood. (PALE DOCK.) Rather tall (2--6 high); _leaves ovate- or oblong-lanceolate_, acute, pale, thickish, obscurely veiny (the cauline 3--6' long, contracted at base into a short petiole); racemes spike-like and panicled, nearly leafless; whorls crowded; _pedicels nodding, shorter than the fruiting calyx; valves broadly ovate_ or obscurely heart-shaped, obtuse or acutish, entire, loosely reticulated (about 2" broad), one with a conspicuous grain, the others with a thickened midrib or naked. (R. Britannica, _Gray_; not _L._)--Moist grounds, N. Y. and N. J. to Minn., and Kan.

4. R. saliciflius, Weinmann. (WHITE DOCK.) Rather low (1--3 high); root white, _leaves narrowly or linear-lanceolate_, or the lowest oblong; whorls much crowded; _pedicels much shorter than the fruiting calyx; valves deltoid-ovate_, obtusish or acutish (about 1" long), one, two or sometimes all with a conspicuous often very large grain; otherwise nearly as n. 3.--Salt marshes, from Newf. to N. Eng., about the Great Lakes, and far westward.

5. R. verticillatus, L. (SWAMP DOCK.) Rather tall (3--5 high); leaves lanceolate or oblong-lanceolate, rather obtuse, thickish, pale-green, the lowest often heart-shaped at base; racemes nearly leafless, elongated, loose, the whorls crowded or the lower ones distant; fruit-bearing _pedicels slender, club-shaped, abruptly reflexed, 3--4 times longer than the fruiting calyx; valves dilated-rhomboid, obtusely somewhat pointed, strongly rugose-reticulated_, each bearing a very large grain.--Wet swamps, common.

[++][++] _Naturalized European weeds; lower leaves mostly heart-shaped at base._

R. CRiSPUS, L. (CURLED DOCK.) Smooth (3--4 high); _leaves with strongly wavy-curled margins, lanceolate_, acute, the lower truncate or scarcely heart-shaped at base; _whorls crowded in prolonged wand-like racemes, leafless above; valves round-heart-shaped, obscurely denticulate_ or entire, mostly all grain-bearing.--In cultivated and waste ground, very common. A hybrid of this with the next is reported from Ma.s.s., N. Y., and Md.

R. OBTUSIFLIUS, L. (BITTER DOCK.) Stem roughish; _lowest leaves ovate-heart-shaped, obtuse_, rather downy on the veins beneath, somewhat wavy-margined, the _upper oblong-lanceolate, acute; whorls loose and distant; valves ovate-halberd-shaped, with some sharp awl-shaped teeth at base_, strongly reticulated, one of them princ.i.p.ally grain-bearing.--Fields, etc., common.

R. SANGUiNEUS, L. _Leaves oblong-lanceolate_, often fiddle shaped, wavy-margined; _whorls distant, in long slender leafless spikes_; pedicels very short, jointed at base; _valves narrowly oblong, obtuse, entire_, one at least grain-bearing; veins of the leaf red, or green.--Waste and cultivated ground.

R. CONGLOMERaTUS, Murray. (SMALLER GREEN DOCK.) Like the last, but leaves not fiddle-shaped, and panicle leafy; pedicels short, jointed below the middle; valves acutish, all grain-bearing.--Moist places.

[*][*] _Annuals, low; valves bearing long awns or bristles._

6. R. maritimus, L. (GOLDEN DOCK.) Minutely p.u.b.escent, diffusely branched, 6--12' high; leaves lance-linear, wavy-margined, the lower auricled or heart-shaped at base; whorls excessively crowded in leafy and compact or interrupted spikes; valves rhombic-oblong, lance-pointed, each bearing 2--3 long awn-like bristles on each side, and a large grain on the back.--Sea-sh.o.r.e, Ma.s.s. to N. C.; also from Ill. to Minn., and westward.

-- 2. ACETSA. (SORREL.) _Flowers dicious, small, in a terminal naked panicle; herbage sour; some leaves halberd-shaped; smooth perennials, spreading by running rootstocks, flowering in spring._

7. R. hastatulus, Baldw. Stem simple, 1--2 high; leaves nearly as in the next; _pedicels jointed at or below the middle; valves of the fruiting calyx round-heart-shaped_, thin, finely reticulated, naked, _many times larger than the achene_. (R. Engelmanni, _Ledeb._)--S. W.

Ill. to E. Kan., Tex., and Fla.; Riverhead, Long Island (_Young_).

R. ACETOSeLLA, L. (FIELD or SHEEP SORREL.) Low (6--12' high); leaves narrow-lanceolate or linear, halberd-form, at least those of the root, the narrow lobes entire; _pedicels jointed with the flower; valves scarcely enlarging in fruit, ovate_, naked.--Abundant everywhere. (Nat.

from Eu.)

R. ACETSA, L. (SORREL DOCK.) Like the last, but taller (1--3 high); leaves oblong or broadly lanceolate; _valves enlarging in fruit and orbicular, the outer reflexed_.--Charlotte, Vt., and Penn Yan, N. Y.

(Nat. from Eu.)

4. POLGONUM, Tourn. KNOTWEED.

Calyx mostly 5-parted; the divisions often petal-like, all erect in fruit, withering or persistent. Stamens 4--9. Styles or stigmas 2 or 3; achene accordingly lenticular or 3-angular. Embryo placed in a groove on the outside of the alb.u.men and curved half-way around it; the radicle and usually the cotyledons slender.--Pedicels jointed. Ours all herbaceous, with fibrous roots (except n. 19), flowering through late summer and early autumn. (Name composed of p????, _many_, and ????, _knee_, from the numerous joints.)

-- 1. POLYGONUM proper. _Flowers in axillary fascicles or spicate with foliaceous bracts; leaves and bracts jointed upon a very short petiole adnate to the short sheath of the 2-lobed or lacerate scarious stipules; stems striate; calyx 5--6-parted, usually more or less herbaceous; stamens 3--8, the 3 inner filaments broad at base; styles 3; cotyledons inc.u.mbent; alb.u.men h.o.r.n.y; glabrous annuals, except n. 1._ (-- Avicularia, _Meisn._)

[*] _Leafy throughout._

1. P. maritimum, L. _Perennial_, at length woody at base (or sometimes annual), prostrate, _glaucous_, the stout stems very shortly jointed; _leaves thick_, oval to linear-oblong (3--10" long), exceeding the nodes; stipules very conspicuous; sepals petaloid; stamens 8; _achene smooth and shining, exserted_.--Sea-coast from Ma.s.s. to Ga. (Eu.)

2. P. aviculare, L. Slender, _mostly prostrate or ascending, bluish-green_; leaves oblong to lanceolate (3--10" long), usually acute or acutish; _sepals hardly 1" long_, green with pinkish margins; stamens 8 (rarely 5); achene dull and minutely granular, mostly included.--Common everywhere in yards, waste places, etc. (Eu., Asia.)

3. P. er.e.c.t.u.m, L. _Stouter, erect_ or ascending (1--2 high), _yellowish_; leaves oblong or oval (--2' long), usually obtuse; _flowers mostly 1" long_, often yellowish, on more or less exserted pedicels, stamens 5--6; achene dull, included (P. aviculare, var.

er.e.c.t.u.m, _Roth_.)--Common, by waysides, etc.

[*][*] _Leaves much reduced above and bract-like._

4. P. ramosissimum, Michx. Erect or ascending (2--4 high), _yellowish green_; leaves lanceolate to linear (1--2' long), acute; _flowers_ and achene _as in_ n. 3, but sepals more frequently 6, the _stamens_ 3--6, and the achene mostly smooth and shining--Sandy sh.o.r.es and banks of streams, E. Ma.s.s to N. Y., west to Minn., Ark., Tex., and far westward.

5. P. tenue, Michx. _Stem angled_, erect (--1 high), glabrous, or slightly scabrous at the nodes; _leaves_ narrowly linear to lanceolate (1--2' long), _3-nerved_, acute at each end and often cuspidate, the margins somewhat scabrous and at length revolute; _flowers_ often solitary, _nearly sessile; stamens_ 8; achene included, dull black--Dry soil, N. Eng. to S. C., west to Minn., Mo., and Tex.

6. P. camprum, Meisn. _Stem terete_, erect or ascending (2--3 high), glabrous; _leaves deciduous_, linear to oblong, usually short; _pedicels slender, exserted from the scarious sheaths_; stamens 8.--E. Kan. to Tex.

-- 2. PERSICaRIA _Flowers in dense spikes, with small scarious bracts; leaves not jointed on the petiole; sheaths cylindrical, truncate, entire, naked or ciliate-fringed or margined; calyx colored, 5-parted, appressed to the fruit; stamens 4--8, filaments filiform; cotyledons acc.u.mbent._

[*] _Sheaths and bracts not ciliate or fringed; sepals not punctate; style 2-cleft._

7. P. lapathiflium, L. Annual, branching, 1--4 high, glabrous or the peduncles often minutely glandular; leaves lanceolate, attenuate upward from near the cuneate base and ac.u.minate somewhat scabious with short appressed hairs on the midrib and margin or rarely floccose-tomentose beneath; sheaths and bracts rarely somewhat ciliolate; spikes oblong to linear (--2' long), dense, erect or nearly so; flowers white or pale rose-color; stamens 6; achene ovate, rarely 1" broad. (P. nodosum, _Pers._, P. incarnatum, _Man._, in part.)--Wet places; N. Eng. and Can.

to Ill., Wisc., and far westward. Very variable. (Eu.)

Var. incarnatum, Watson. Leaves often large (6--12' long, 1--3' wide); spikes more slender and elongated (2--4' long), nodding. (P. incarnatum, _Ell._)--Penn. to Ill., Mo., and southward.

Var. incanum, Koch. Low (6--12' high); leaves small, obtusish, more or less h.o.a.ry beneath with floccose tomentum; spikes short.--Cayuga Lake, N. Y., Ont., sh.o.r.es of L. Superior, and northwestward. (Eu.)

8. P. Pennsylvanic.u.m, L. A similar species, but the _branches above and especially the peduncles beset with stipitate glands_; flowers larger and often bright rose-color, in short erect spikes, often on exserted pedicels; stamens usually 8; achene nearly orbicular, over 1"

broad.--Moist soil, in open waste places, common.

9. P. amphibium, L. Perennial, _aquatic_ or rooting in the mud, _stout and glabrous_ or nearly so, not branching above the rooting base; _leaves usually floating, thick_, smooth and shining above, mostly long petioled, _elliptical to oblong_ or sometimes lanceolate, _acutish_, cuneate or cordate at base (2--5' long); spike terminal, _dense, ovate or oblong_ (--1' long); flowers bright rose-color (1--3" long); the 5 stamens and 2-cleft style exserted.--Widely distributed and rather common. (Eu., Asia)

10. P. Muhlenberghii, Watson. Perennial, in muddy or dry places, dec.u.mbent or suberect, _scabrous with short appressed or glandular hairs; leaves thinner, rather broadly lanceolate, narrowly ac.u.minate_ (4--7' long); _spikes more elongated_ (1--3' long), often in pairs; flowers and fruit nearly as in the last. (P. amphibium, var. terrestre, _Gray_, Manual; not _Lurs_)--N. Eng. to Fla., westward across the continent.

[*][*] _Sheaths and bracts bristly ciliate or the sheaths foliaceously margined._

[+] _Sepals not punctate; style 2-cleft; achene somewhat flattened._

11. P. Hartwrghtii, Gray. _Perennial_, very closely allied to n. 9, growing usually in mud, the ascending stems rooting at base and very leafy, _more or less rough-hairy_, at least on the sheaths and bracts, the former ciliate and _often with abruptly spreading foliaceous borders_; leaves rather narrow (2--7' long), on very short petioles; _flowers and fruit as in n. 9._--N. Eng. and N. Y., to Minn., Iowa, and far westward. When growing in water the floating leaves are thicker and glabrous.

12. P. Careyi, Olney. Annual, erect, the stem (3--5 high) and peduncles _glandular-bristly; leaves narrowly lanceolate_, attenuate to both ends, roughish; sheaths ciliate or sometimes margined; spikes slender, loose and nodding; flowers purplish; _stamens mostly_ 5.--Shady swamps, S.

Maine and N. H. to Penn. and Ont.