2 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 
[PuatTe 23. ] 
23. Polygonum segetum Humboldt, Bonpland & Kunth. 
Polygonum segetum Huamboldt, Bonpland & Kunth, Noy. Gen. 2: 177 (1817); 
Sprengel, Syst. 2: 257; Meisner, Monog. 67, in DC. Prodr. 14: 120, 
Polygonum Ludovicianum Meisner in DC. Prodr. 14; 116 (1856). 
Polygonum segetum var. genuinum Meisner in DC. Prodr. 14: 121 (1856). 
Perennial, glabrous below, pubescent or glandular about the inflorescence. Stem 
erect, 4-8 dm. long, simple or sparingly branched, enlarged at the nodes; leaves nar- 
rowly lanceolate, 6-16 em. long, .7-1.5 em. broad, acuminate at both ends, sometimes 
undulate and slightly crisped, glabrous except occasional short stout hairs on the mid- 
rib and the ciliate margin, not punctate, short-petioled; petioles about 1 cm. long; ocreae 
cylindric or narrowly funnelform, 1-1.5 cm. long, those on the lower part of the stem 
glabrous, the upper pubescent or glandular, especially about the inflorescence, naked 
or fringed with a few short bristles; inflorescence paniculate more or less compound, 
the ultimate divisions ending in spicate often geminate racemes; racemes erect, 2-4 cm. 
long, cylindric, rather loosely flowered; ocreolae funnelform, 2-2.5 mim. long, oblique, 
coriaceous with a somewhat membranous edge, more or less scurfy; pedicels at length 
about 3 mm. long, strongly angled; calyx 2-2.5 mm. long, five-parted to near the 
base, the segments oblong, obtuse; stamens six or seven, included; style about 1.5 mm. 
long, two-parted to below the middle; achene lenticular, 2.5 mm. long, ovoid, usually 
somewhat plano-concaye, rather long-pointed, dark brown, minutely granular, dull. 
Louisiana, Mexico and the West Indies; also in Colombia. 
