pint el 
Polvgonaceae 139 
FF. Leaves not dark-blotched; plant hispid unless in water; spike only 1. W. 
Es P. hartwrightii Gray 
AA.  Sheaths nearly or quite without cilia. 
G. Annual, in damp places; spikes several. 
H. Leaves white-tomentose beneath. E. (P. lapathifolium incanum.) 
P. tomentosum Schrank (Woolly Smart-weed) 
HH. Leaves not white-tomentose beneath. 
I. Spikes erect; akene orbicular. FE. 
P, pennsylvanicum L. 
II. Spikes drooping at least at tip; akene ovoid. 
J. Calyx and style each parted to below the middle. W. E. (P. lapathi- 
folium incanum; P. lapathifolium nodosum; P. nodosum. ) 
P. lapathifolium L. 
JJ. Calyx and style each parted nearly to the base. E. 
P. incarnatum Ell. 
GG. Perennial, in water or mud; spike only 1. 
K. Leaves oblong-elliptic, obtuse; spikes 1.22.5 ¢m. long; peduncles glabrous or 
nearly so. W. E. P. amphibium L. (Water Smart-weed) 
KK. Leaves ovate, acuminate; spikes 3—10 cm. long; peduncles hispid, often 
glandular. W.E. (P. muhlenbergii.) 
P. emersum Brit. (Swamp Smart-weed) 
Subgenus BISTORTA (Smart-weEED)—Herbs, perennial, alpine or subalpine, 
glabrous, with creeping rhizomes; stem simple. Leaves pinnately veined, not jointed to 
the petiole; sheaths oblique, truncate, naked. Flowers in dense spike-like racemes; bracts 
scarious, ovate or lanceolate, naked. Perianth colored, deeply 5-cleft, at length ap- 
pressed to the akene. Stamens 8; filaments filiform. Styles 3, long. Akene 3-angled. 
_ A. Rhizome elongated; spike bearing flowers thruout. W. C. E. 
’  P. bistortoides Pursh 
AA. Rhizome corm-like; spike bearing bulblets at base. C. E. 
P. viviparum L. 
Subgenus ACONOGONON (Smart-wEED)—Herbs, perennial. branching, with 
running rhizomes. Leaves pinnately veined, not jointed to the petiole; sheaths naked, en- 
tire or bifid. Flowers in terminal and axillary racemes or panicles or cymelets; bracts 
small. Perianth colored, 5-parted, attenuate at base, at length loosely appressed to the 
akene. Stamens 8; filaments filiform. Styles 3, short. Akene 3-angled. 
A. Sheaths |—12 mm. long; flower clusters mostly axillary. 
B. Sheaths 1—3 mm. long; flowers usually more than 4 in a cluster; perianth seg- 
mented to near the base. C. 
P. newberryil Small 
BB. Sheaths 6—12 mm. long; flowers 2—4 in a cluster; perianth segmented to 
near the middle. C. E. P. davisiae Brew. 
AA.  Sheaths 1 3—50 mm. long; flower clusters mostly panicled. 
C. Leaves lanceolate to ovate-lanceolate; perianth white or greenish; akene obovoid. 
f NE P. alpinum All. 
CC. Leaves ovate to ovate-lanceolate; perianth white or pinkish; akene ovoid. EF. 
(P. alpinum alaskensis; P. alpinum foliosum.) 
P. phytolaccaefolium Meisn. 

