662 



POLYGONACEAE. 



Vol. I. 



5. Polygonum neglectum Besser. Narrow- 

 leaved Knotweed. Fig. 1620. 



P. neglectum Besser, Enum. PI. Vol. 45. 1822. 

 P. aviculare angustissimum Meisn., in DC. Prodr. 14 • 08 

 1856. 



Annual, dull green, stem usually widely much-branched 

 at the base, mostly i°-2° long. Leaves narrow, elliptic 

 to elliptic-lanceolate or linear, 3"-io" long, acute or 

 somewhat acuminate at both ends, sessile or nearly so, 

 those of the branchlets often conspicuously small and 

 inclined to be obtuse; ocreae silvery-brown; flowers 

 often 2 together, sessile or short-pedicelled ; sepals 

 green, except the pale pink to purplish-red margins, 

 about I" long; achene 3-angled, ovoid, about 1" long, 

 acuminate, striate-reticulated. 



A weed in yards, cultivated and waste grounds, nearly 

 throughout North America, and common in nearly all parts 

 of the north temperate zone. June-Nov. 



7. Polygonum buxiforme Small. Shore 

 Knotweed. Fig. 1621. 



P. buxiforme Small, Bull. Torr. Club 33 : 56. 1906. 



Annual, stout, bright green or slightly glaucous, 

 stem i°-4° long, prostrate, diffusely branched from 

 a woody base, striate. Leaves broad, oblong, oblong- 

 lanceolate or oblanceolate or oval, 2"-o" long, obtuse 

 or subacute at the apex, thick, short-petioled; ocreae 

 at length lacerate; flowers 2-6 in each cluster; sepals 

 green, except the whitish margins, or carmine ; 

 stamens 8; achene broadly ovoid, 3-angled, i"-ii" 

 long, more or less contracted at the apex, dark- 

 brown, the faces often granular. 



On shores and in waste places, New Brunswick to 

 Minnesota and British Columbia, south to Virginia, Illi- 

 nois and New Mexico. Aug.— Sept. Mistaken in first 

 edition for P. littorale Link, a European species with 

 reddish-brown narrower and shining achenes, which has 

 recently been reported from Mt. Desert, Maine. 



Polygonum provinciale C. Koch, a more slender plant than P. buxiforme, with narrower, 

 revolute acute leaves, smaller flowers and narrower achenes, occurs locally in our range. It is 

 native of Europe. 



8. Polygonum prolificum (Small) Robinson. 

 Proliferous Knotweed. Fig. 1622. 



P. ramosissimum prolificum Small, Bull. Torr. Club 21 : 



171. 1894. 

 P. prolificum Robinson, Rhodora 4 : 68. 1902. 



Annual, glabrous, stem erect or nearly so, 1J tall 

 or less, usually much branched. Leaves narrow, 

 spafulate, linear-spatulate or nearly oblong, rather 

 slender-petioled, s"-is" long, obtuse or acutish; 

 ocreae inconspicuous, early much-lacerate; flowers 

 exceeded by the ocreae ; calyx sessile or nearly so, 

 the sepals pinkish, slightly enlarged in fruit ; stamens 

 mostly 5; achene rhombic-ovoid, about ii" long, 

 3-angled, slightly roughened, abruptly contracted at 

 the apex. 



In brackish marshes and on the sea-shore, Quebec and 

 Maine to Virginia ; and in the interior from South Da- 

 kota to Missouri and Colorado, July-Oct. 



