1919] Fernald,— New Polygonum 141 
with constancy. Detailed study in the herbarium brings out other 
points which will be discussed below and which justify the descrip- 
tion of the indigenous plant as 
Potyconum puritanorum, n. sp., annuum; caule gracile decum- 
bente adscendente vel erecto 1-6 dm. longo deinde ramosissimo 
ramis glabris vel plus minusve strigosis; ochreis laxe cylindricis 
strigosis ciliatis; foliis rhomboideo-lanceolatis utrinque acuminatis 
acutis vel subacutis breviter petiolatis vel subsessilibus plerumque 
immaculatis subtus plus minusve strigosis primariis 3-10 cm. longis 
0.7-1.6 cm. latis; pedunculis erectis glabris vel strigosis longioribus 
1-5 cm. longis; spicis densissimis cylindricis primariis 1-3.5 cm. 
longis 4-6.5 mm. crassis; ochreolis brunnescentibus ciliatis; peri- 
anthiis roseis vel purpureis 1.8-2 deinde 2.4-2.6 mm. longis maturitate 
laevibus vel obsolete nervosis; pedicellis inclusis vel paullo exsertis; 
staminibus 5-6; achaeniis ovato-orbicularibus biconvexis vel trigonis 
atris lucidis 2 mm. longis 1.4 mm. latis plerumque inclusis. 
Annual: stem slender, decumbent, ascending or erect, 1-6 dm. long, 
finally much branched; branches glabrous or more or less strigose: 
ochreae loosely cylindrie, strigose, ciliate: leaves rhombic-lanceolate, 
acuminate at base and apex, acute or subacute, short-petioled or 
subsessile, usually unspotted, more or less strigose beneath; the 
primary ones 3-10 cm. long, 0.7-1.6 cm. broad: peduncles erect, 
glabrous or strigose; the longer 1-5 cm. long: spikes very dense, 
cylindric; the primary 1-3.5 cm. long, 4-6.5 mm. thick: ochreolae 
brownish, ciliate: perianths rose-pink or purple, 1.8-2, becoming 
2.4-2.6 mm. long, in maturity smooth or only obsoletely nerved: 
pedicels included or a little exserted: stamens 5 or 6: achenes ovate- 
orbicular, biconvex or trigonous, black, lustrous, 2 mm. long, 1.4 mm. 
broad, mostly included.— Plymouth and Barnstable Cos., Massa- 
cHUSETTS: sandy shore of Clear Pond, Plymouth, August 30, 1913, 
Fernald, Hunnewell & Long, no. 9,402; damp sandy beach of Boot 
Pond, Plymouth, September 6, 1913, Fernald, Hunnewell & Long, no. 
9,400; damp sandy beach of Great South Pond, Plymouth, September 
6, 1913, Fernald, Hunnewell & Long, no. 9,401; gravelly and sandy 
beach, Little Sandy Pond, Plymouth, August 7 & 8, 1918, Fernald & 
Clark, no. 16,755; wet sandy or gravelly lower beach, Half-way Pond, 
Barnstable, September 4, 1918, Fernald & Long, no. 16,759; Yar- 
mouth, September 10, 1907, E. W. Sinnott; Scargo Pond, Dennis, 
August 22, 1907, E. W. Sinnott; sandy strand of a pond, Dennis, 
October 1, 1915, C. A. Weatherby; sandy beach, Buck Pond, Harwich, 
July 8, 1918, Fernald, no. 16,752; sandy and gravelly beach, Hawk's 
Nest Pond, Harwich, July 28, 1918, Fernald, no. 16,754; bare sandy 
beach, east end of Long Pond, Harwich, August 14, 1918, Fernald & 
Long, no. 16,756 (rype in Gray Herb.); sandy beach, Seymour Pond, 
Harwich, September 19, 1918, Fernald & Weatherby, no. 16,762; 
