Part 145 (2/2)

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 s.h.i.+ning, 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 s.h.i.+ning--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 s.h.i.+ning 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.

<script>