I'objijonum. rOLYGOXACEyE. 



i-O 



§ 2. Flowers splcate, Manj and ses.ile in the axils offoUacoons bracts ■ leaves 

 <^fj'-acts notjouUcU at base, striately S-nero^l ; stipules /briate or 

 2-lobcd: penanth colored, ^-parted, at Icn.jtk appressed to the tria\undar 

 akeae: stamens^- cnncr filaments scarcely didLd : stylelV^^Sn 

 Svt'wLsoT "■"' '''"'"'"'^ annualsUoith narroi riyu/ !:::^::t 



1 2. P. CaUfornicum, Meisner. Stems 3 to G inches Inyl,, striate and l.rownish 

 glabrous or nuuutey scabrous : leaves Hnear to filifor.n, gV 15 lu o To ' ! 



c ate : spikes very s ender, elongated, the bracts subulate,! or 2 linos lon'^^th,^ es 

 sheatlung deeply lacerato-fringed, a line long, nearly 'equalling th ro.^ co o ed 

 Mowers: akene nanouly lanceo ate, slightly exsertcd ; styles slightly dive^'t _ 

 DC. Irodr. x.v. lOU ; Watson, 1. c., the fruit described from iminatu.e specimens 



o..^'y SMS;'iS;;e;;t'"''lvI'' l7r''^ i" *'"^ f '^'•'^;^eva.la)to tl.e Columbia Hiver (A'.^/.//), 

 U.y sou, latlici lie.iue.it. Iwo a.l.iitional n.embeis of this .sectiou are described ou page 479 



§ 3. Flowers fascicled, in usually dense spikes, with small scarious bracts • leavers 

 not jointed on the petwle, jrinnafcly many-veined: sheaths cflindrical and 

 truncate, scarajus, entire, naked or ciliatc-frin.jcd or man/i'ncd: perianth 

 colored, o-paned, appressed to the lenticular or t riany alar akene : stamens 

 4 <o » ; filaments filiform : stiymas 2 or o. — Persicaria, Linn. 

 * Sheaths and bracts not ciliate nor frinyed : sepals not punctate : style 2-cleft 

 and akene flattened or lenticular. 

 U P nodosum, Persoon. Annual, often stout, 1 to 4 feet hi-di, branching 

 mostly glabrous, often sparingly and minutely glandular on the i)eduncles : leaves 

 ratluu- narrowly lanceolate, attoTiuatc upward from near the base and acuminate 

 omioato at base and shortly pet i.. led, somewhat scabrous with short prickly haii-s on 

 the midrib and margins : spikes axillary and terminal, oblong and erect or often 

 inear and nodding, an inch long or more : flowers white or light rose-color a line 

 ..ng or nearly so : stamens 6, and styles 2, included : akene ovate, less than a line 

 broad. — Meisner, 1. c. 118. 



in O.oTnU'J'm ' S="'Jo«<:VnlIey and Santa Qvn?. {Bracer) and Alanieda County {Kellogq), also 

 n ).egon(//,,Oand New Me.xico (/.W/cr)-a form apparently identical with that of Euro,.e 

 Tit^aium'uX "'"'''' ""'""■''^^'^ sj'ikesand larger leaves, perhaps running into 



P. PFNNSYi.VANictTM I inn A similar species, but the branches above and esj-ecinlly the pc- 

 d ncles beset with stii.i ate glan.ls : flowers larger and bright rose-color, in short erect spikes, 

 otten on exserted pedicels : stamens usually 8 : style bifi.l, exserted : akene nearlv orbicular, over 

 a line broad — Common in the Atlantic States and west to Colomdo and ^omv^ (Thurbcr), and 

 to be expected in Calilornia, at least as an introduced weed. 



14 P. amphibium, Linn. Perennial, aquatic, stout and glabrous or nearly so 

 not branching above the rooting ])ase : leaves iloating, thick, smooth and shining 

 above, usually loug-petioled, elliptical to oblong or sometimes lanceolate, acutish or 

 acute, cuneate or cordate at base, 2 to 5 inches long : sheaths leaf-bearing at about 

 the iukUUo : spike terminal, dense, ovate or oblong, a half to an inch long, on a 

 usually short peduncle : ilowers bright rose-color, U to 3 lines long, the 5 stamens 

 and 2-cleft style exserted: akene lenticular, smooth. — Meisner, 1. c. 115. 



Perhaps not found west of the Siena Nevada, but common in fresh waters about Mono Lake 

 and Lake lahoe, ranging northward to British Columbia, eastward across the continent, and to 

 Mexico ; 111 the Old World from W. Kuiopc to China. In shallow water or on mu(hly banks the 

 stems become erect, tiie p.^tiidcs shorter, and the whole plant more strigose pubescent 



15, P. Muhlenbergii, Watson. I^erennial. in muddy or dry i)laces, scabrous 

 with short appressed or glandular hairs, especially upon the leaves and upper part 

 of the simple stem : leaves thinner, rather broadly lanceolate, narrowly acuminate, 

 usually rounde<l or cordate at base, 4 to 7 inches long : spikes more elongated, 1 to 



