GENUS /. 



BUCKWHEAT FAMILY. 



667 



In waste places, throughout temperate North America. Naturalized from Europe. Some- 

 times a troublesome weed. Native also of Asia. Willow-weed. June-Sept. 



Persicaria tomentosa (Schrank) Bicknell (Polygonum tomentosum Schrank) has been sepa- 

 rated from P. lapathifolia by the pubescent leaves and slightly larger flowers and fruits. 



4. Persicaria portoricensis (Bertero) Small. 

 Dense-flowered Persicaria. Fig. 1633. 



Polygonum densiflorum Meisn. in Mart. Fr. Bras. 5 : Part 



!, 13- !855. Not Blume, 1825-26. 

 Polygonum portoricense Bertero ; Meisn. in DC. Prodr. 



14: 121. 1856. 

 Persicaria portoricensis Small, Fl. SE. U. S. 377. 1903. 



Perennial, more or less scurfy; stem erect, decum- 

 bent or floating, 3-5 long or longer, branched, en- 

 larged at the nodes, often dark brown. Leaves lan- 

 ceolate or linear-lanceolate, \\'-\2 r long, acuminate 

 at both ends, obscurely punctate, short-petioled, the 

 nerves prominent beneath ; ocreae cylindric, sometimes 

 bristly when young, naked when mature, sometimes 

 hispid ; racemes spicate, paniculate, often in pairs, i'-s' 

 long, dense, erect ; calyx white or whitish, 5-parted to 

 near the base; stamens 6-8, included; style 2-3-cleft, 

 somewhat exserted ; achene lenticular and strongly 

 biconvex or 3-angled, l"-ii" long, broadly oblong, or- 

 bicular or even broader than high, black, smooth and 

 shining, or minutely granular. 



In wet soil, southern New Jersey and Missouri to Florida, Texas, the West Indies and^South 

 America. May-Nov. 



5. Persicaria pennsylvanica (L.) Small. Penn- 

 sylvania Persicaria. Fig. 1634. 



Polygonum pennsylvanicum L. Sp. PI. 362. 



Persicaria pennsylvanica Small, Fl. SE. U. S. 377. 1903. 



Annual, glabrous below ; stem erect, simple or branched, 

 i-3 tall, the upper parts, the peduncles and pedicels 

 glandular. Leaves lanceolate, acuminate at the apex, 

 petioled, ciliate, 2'-n' long, the upper sometimes glandu- 

 lar beneath ; ocreae cylindric, thin, naked, glabrous ; 

 racemes panicled, erect, thick, oblong or cylindric, dense, 

 I '-2' long; calyx dark pink or rose-color, 5-parted; 

 stamens 8 or fewer, style 2-cleft to about the middle ; 

 achene orbicular or mostly broader than high, \\" long, 

 short-pointed, lenticular, smooth, shining. 



In moist soil, Nova Scotia to Ontario, Minnesota, Florida 

 and Texas. Ascends to 2000 ft. in Virginia. July-Sept. 



Persicaria omissa (Greene) Small, differing by an ovoid 

 achene and copiously glandular peduncles, recently found in 

 western Kansas, was first discovered in Colorado. 



6. Persicaria longistyla Small. Long-styled 

 Persicaria. Fig. 1635. 



Polygonum longisfylum Small, Bull. Torr. Club 21 : 



169. 1894. 

 Persicaria longistyla Small, Fl. SE. U. S. 377. 1903. 



Annual or perennial, glabrous except the glan- 

 dular upper branches and peduncles; stem erect, 

 rather slender, i-3 tall, becoming somewhat 

 woody below. Leaves lanceolate or ovate-lanceo- 

 late, i'-6' long, acuminate at both ends, petioled, 

 their margins undulate, slightly crisped, more or 

 less ciliolate ; ocreae cylindric, entire, brittle, soon 

 falling away; racemes panicled, sometimes gemi- 

 nate, i '-4' long, rather dense, erect ; calyx lilac, 

 spicuously exserted ; stigmas black ; achene broadly 

 5-parted to below the middle, the lobes petaloid ; 

 stamens 6-8, included ; style 2-parted, slender, con- 

 ovoid, lenticular, slightly gibbous on both sides, 

 long-pointed, black, granular, but somewhat shin- 

 ing, i\" long. 



, In moist soil, southern Illinois, Missouri and Kansas 

 to Louisiana and New Mexico. Aug.-Oct. 



