Populus x jackii (balm of gilead) Salicaceae 153 -- lf stalk terete; lvs drk green, waxy; flat or somewhat heart-shaped at base

Porteranthus trifoliatus (mountain Indian physic) Rosaceae (5 5 10+ 5) --

Portulacaceae (purslane) -- Claytonia (spring beauty); Portulaca (purslane)

Portulaca grandiflora (moss rose) Portulacaceae (4-6 2 6-10 3+) 099 fls large; lvs AE, sessile, short

Portulaca oleracea (common purslane) Portulacaceae (4-6 2 6-10 3+) 098 -- lvs OE, succulent, sessile, flat-tipped

Potamogeton amplifolius (bigleaf pond weed) 612

Potamogeton confervoides (alga pond weed) 610

Potamogeton crispus (curly pond weed) 609

Potamogeton diversifolius (common snailseed pond weed) 609 -- lvs clear, crisped edges

Potamogeton epihydrus (ribbonleaf pond weed) 611

Potamogeton foliosus (leafy pond weed) 611

Potamogeton friesii (Frie's pond weed) 610 -- chiefly calcareous

Potamogeton gramineus (variable pond weed) 612

Potamogeton illinoensis (Illinois pond weed) 613

Potamogeton natans (floating pond weed) 613

Potamogeton nodosus (longleaf pond weed) 612

Potamogeton oakesianus (Oake's pond weed) 613

Potamogeton obtusifolius (blunt-leaf pond weed) 611

Potamogeton ogdenii (Ogden's pond weed) 610

Potamogeton pectinatus (sago pond weed) 609 -- lvs many, linear, grass-like

Potamogeton perfoliatus (perfoliate pond weed) 613 --lvs clear & apple-green

Potamogeton praelongus (whitestem pond weed) 613

Potamogeton pulcher (spotted pond weed) 612

Potamogeton pusillus (slender pond weed) 611

Potamogeton richardsonii (Richardson's pond weed) 613 -- lvs almost clasping, long tear-drop shape

Potamogeton robbinsii (fern pond weed) 609

Potamogeton sp. (pond weed) Potamogetonaceae (0 4 4 4 us anemophilous)

Potamogeton spirillus (northern snailseed pond weed) 608

Potamogeton strictifolius (straight leaved pond weed) 610

Potamogeton vaginatus (big sheath pond weed) 609

Potamogeton vaseyi (Vasey's pond weed) 611

Potamogeton zosteriformis (flatstem pond weed) Potamogetonaceae (04 4 4) 610 -- lvs very linear

Potentilla anserina (silverweed cinquefoil) 225 -- prostrate; lflts silvery beneath

Potentilla argentea (silvery cinquefoil) 223 -- lflts silvery below

Potentilla arguta (tall cinquefoil) 226 -- flowers white; 7-11 egg-shaped lflts; dry fields & rocky slopes

Potentilla canadensis (dwarf cinquefoil) 222 -- the 5 lflts toothed only above the middle

Potentilla flabelliformis 224 --

Potentilla fruticosa (shrubby cinquefoil) 226 -- shrub; fls yellow, 3/4" wide; lflts silky-hairy; bogs, pastures & rocky pls.

Potentilla norvegica (rough cinquefoil) 223 -- 3 lflts; hairy, stout stem

Potentilla palustris (marsh cinquefoil) 226 -- red-purple fls; swamps & bogs; lflts 5-7, blunt-tipped

Potentilla recta (rough-fruited cinquefoil) 223 -- 7 lflts, lance-shaped, coarsely toothed

Potentilla reptans (creeping cinquefoil) 222 -- yellow; stems creeping; waste pls.

Potentilla rivalis (brook cinquefoil) 223 -- pale yellow; western occ adventive

Potentilla simplex (common cinquefoil) 222 -- 5 lflts toothed for 3/4s of their length

Potentilla sp. (cinquefoil) Rosaceae (5 5 5-N 1) --

Potentilla tridentata (three-toothed cinquefoil) 225 -- white fls; lflt ends w/ 2 notches

Prenanthes alba (white lettuce) 587 -- invol glabrous; fls creamy white; stem us. purplish w/ a whitish bloom; lvs w/ whitish bloom

Prenanthes altissima (tall white lettuce) 588 -- invol glabrous; fls greenish-white; lvs very variable; basal lvs triangular, etc.

Prenanthes autumnalis (slender rattlesnake root) 587 -- invol glabrous; pink or pale lavender; sandy, coastal

Prenanthes racemosa Asteraceae/Lactuceae 586 -- invol. pubescent; infl cylindric; pink or purplish; steambanks, moist meadows

Prenanthes serpentaria (lion's foot rattlesnake root) 587 -- invol pubescent; fls creamy white

Prenanthes sp. (rattlesnake root) Asteraceae/Lactuceae -- AT

Prenanthes trifoliolata (tall rattlesnake root) 588 -- invol glabrous; white to yellow-white, no bloom Primulaceae (primrose) -- Anagallis, Centunculus, Glaux, Hottonia, Lysimachia, Samolus, Trientalis

Proserpinaca intermedia (intermediate mermaidweed) Haolragaceae 291 --

Proserpinaca palustris (common mermaidweed) Haloragaceae 290 --

Proserpinaca pectinata (coastal plain mermaidweed) Haloragaceae 290 -- lvs smaller, more numerous

Prunella laciniata (Eurasian self-heal) Lamiaceae ((5) (5) 2+2 1) 423 --

Prunella vulgaris (self-heal) Lamiaceae ((5) (5) 2+2 1) 423 -- violet or purplish coming out from prominent term bracts; OT lance/egg

Prunus alleghaniensis (Allegheny plum) 242

Prunus americana (wild plum) 243 -- egg-shaped lvs, long-pointed; branches often thorny

Prunus angustifolia (chickasaw plum) 242 --

Prunus armeniaca (apricot) 240 -- white or sl pinkish; AT oval fls & fr sessile or nearly

Prunus avium (sweet cherry) 241-- lvs persistently long-hairy beneath, ovate-oblong to obovate; fl clusters bracted

38