Genus 13. 



BUCKWHEAT FAMILY. 



677 



.2. Polygonella americana (F. & M.) Small. Southern Jointweed. Fig. 1657. 



Gonopyrum americanum F. & M. Mem. Acad. St. Petersb. 



(VI.) 4: 144. 1840. 

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



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, 

 ii°-4° high, simple or slightly branched, covered with 

 a ridged more or less scaly bark. Leaves linear or 

 linear-spatulate, l'-i' long, often fascicled on short 

 branches, sessile, rather fleshy, obtuse and revolute at 

 the apex; ocreae scarious-margined, split on one side; 

 racemes 1/-3' long, dense, divergent; calyx white or 

 pink, its three inner segments developing orbicular 

 cordate wings, the two outer reflexed in fruit; pedicels 

 divergent, jointed below the middle; achene elliptic- 

 oblong, il" long, chestnut-brown, pointed at both ends, 

 smooth, shining. 



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



14. BRUNNICHIA Banks; Gaertn. Fr. & Sem. 1 : 213. pi. 45. f. 2. 1788. 



Perennial vines with elongated, grooved much branched stems climbing by tendrils, and 

 alternate entire broad 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, the 

 segments spreading when fresh, converging when dry, the flower-tube much enlarged, coria- 

 ceous and winged on one side in fruit, closely investing the achene. Stamens 7-10, mostly 8; 

 filaments filiform, much dilated at the base. Style 3-parted, the stigmas 2-cleft; ovule 

 solitary, pendulous. Achene 3-angled. Seed irregularly 6-grooved, the embryo in one of 

 its angles. [Name in honor of M. T. Brunnich, Norwegian naturalist.] 



Two known species, the following typical one of southeastern North America, the other of 

 tropical Africa. 



i. Brunnichia cirrhdsa Banks. Brunnichia. Fig. 1658. 



Brunnichia cirrhosa Banks; Gaertn. Fr. & Sem. 1: 213. 

 pi. 45. f. 2. 1788. 



Rajania ovata Walt. Fl. Car. 247. 1788. 



Stem 6°-20° long, somewhat woody, rather tough, 

 slender, grooved. Tendrils filiform; leaves ovate or 

 ovate-lanceolate, acute or acuminate at the apex, 

 truncate or subcordate at the base, i'-6' long, peti- 

 oled, slightly pubescent beneath ; ocreae obsolete or 

 represented by a ring of short bristles; racemes 

 2'-6' long ; flowers in fascicles of from 2-5 ; calyx 

 greenish, 5-parted; stamens exserted; achene ob- 

 long-ovoid, 3" long, brown, smooth, closely invested 

 by the persistent and coriaceous flower-tube which 

 becomes 1' or more in length. 



On banks of streams, southern Illinois to Arkansas 

 and Texas, east to South Carolina and Florida. May- 

 June. Fruit mature in August. 



