568 



POLYGONACEAE. 





7. POLYGONELLA Michx. Fl. Bor. Am. 2: 240. 1803. 



Annual or perennial glabrous herbs, sometimes slightly woody, with erect branched 

 usually conspicuously jointed stems, alternate narrow leaves articulated to the naked ocreae, 

 and small white or greenish flowers in slender panicled racemes. Calyx unequally 5-parted, 

 persistent, its segments petalloid, loosely investing the achene or its base in fruit, the three 

 inner calyx-segments often winged. Stamens 8, included; filaments filiform, or much dilated 

 or auricled at the base; anthers oblong, small. Style 3-parted, short or almost wanting; 

 stigmas capitate; ovary i-celled, ovule solitary. Achene 3-angled, smooth. Embryo slen- 

 der, nearly straight, situated in one of the angles of the seed. [Diminutive of Polygonum.] 



Five or six species, natives of North America. 



1. P. articulata. 



2. P. Americana. 



Annual; inner sepals not winged in fruit; pedicels reflexed. 

 Perennial; inner sepals winged in fruit; pedicels divergent. 



1. Polygonella articulata (I,.) Meisn. Coast Jointweed. (Fig. 1356.) 



Polygonum articulatum L. Sp. PI. 363. 1753. 

 Polygonella articulata Meisn. Gen. 2: 228. i836-'43. 



Annual, glaucous, stem slender, wiry, erect or 

 sometimes diffusely spreading, simple or branched, 

 striate or slightly angled. 4 / -io / long. Leaves 

 linear or linear-subulate (apparently filiform from 

 the revolute margins), sessile, 4 // -2o' / long, jointed 

 to the summits of the ocreae, c}-lindric, slightly ex- 

 panded at the summit; racemes numerous, erect, 

 many -flowered, I'-i^' long; ocreolae crowded or 

 imbricated ; pedicels reflexed ; calyx-segments 

 white with a dark midrib, loosely investing the 

 achene, not winged in fruit; achene narrowly ovoid- 

 pyramidal, pointed, \" long, brown, smooth, 

 shining. 



In sands of the seashore and sandy soil along the 

 coast, Maine to Florida, and on the shores of the Great 

 Lakes. July-Oct. 



2. Polygonella Americana (F. & M.) Small. 



(Fig. 1357.) 



Southern Jointweed. 



Gonopyrum Americanum F. & M. Mem. Acad. St. 



Petersb. (VI.) 4: 144. 1840. 

 Polygonella ericoides Engelm. & Gray, Bost. Journ. Xat. 



Hist. 5: 230. 1845. 

 P. Americana Small, Mem. Torr. Club, 5: 141. 1894. 



Perennial by a long slender root, slightly glaucous, 

 stem erect or ascending, wiry, somewhat flexuous, 

 i/^-4 high, simple or slightly branched, covered 

 with a ridged more or less scaly bark. Leaves linear 

 or linear-spatulate, ^ / -i' long, often fascicled on 

 short branches, sessile, rather fleshy, obtuse and revo- 

 lute at the apex; ocreae scarious-margined, split on one 

 side; racemes i '-3' long, dense, divergent; calyx white 

 or pink, its three inner segments developing or- 

 bicular cordate wings, the two outer reflexed in fruit; 

 pedicels divergent, jointed below the middle; achene 

 elliptic-oblong, i#" long, chestnut-brown, pointed at 

 both ends, smooth, shining. 

 In dry soil, Missouri to Texas, east to Georgia and Alabama. Aug. -Oct. 



8. BRUNNICHIA Banks; Gaertn. Fr. & Sem. i: 213. pi. />. /. 2. 1788. 

 Perennial, glabrous herbs with elongated, grooved much branched stems climbing by 

 tendrils at the ends of the branches, and alternate entire broad cordate petioled leaves, the 

 ocreae obscure or wanting, and small perfect flowers in panicled terminal and axillary 

 racemes, the flowers fascicled in the axils of lanceolate-subulate bracts. Pedicels slender, 

 jointed near the base. Calyx 5-parted, much enlarged, coriaceous and winged on one side 

 in fruit, closely investing the achene, the segments spreading when fresh, converging when 

 dry. Stamens 7-10, mostly 8; filaments filiform, much dilated at the base; anthers ovate- 



