m 
PORTULACCA-PRIMULA. 
PORTULACCA. 12—1. iPortulaccem.) [From ;5or<o, to carry, Zac, milk.] 
olera'cea, (purslane, y, J. ©.) leaves wedge-form ; flowers sessile. 
POTAMOGETON. 4—4. iJunci.) [From potamos, a river, and geiton, adjacent, so called 
because it grows about rivers.] 
natans, (pond-weed, g. J. %.) leaves long-petioled, floating, lance-oval ; at 
first some are sub-cordate. On water. 
Jluitans, (g. Ju. %..) lower leaves long, linear, upper ones lanceolate, nerved, 
coriaceous ; all petioled. In water. 
POTENTILLA. 11—13. {RosacerB.) [From ^oienim, power, so named on account of its sup- 
posed power to heal diseases.] 
A. Leaves digitate. 
canaden'^sis, (common five-finger, y. M. %.) procumbent, sub-ramose, whitish- 
silky ; stipules ovate, gashed ; leaves wedge-ovate, gash-toothed ; stem as- 
cending, and creeping, hirsute; peduncles solitary, elongated ; divisions of 
the calyx lance-linear ; petals orbicular, sub-entire, of the length of the 
calyx. 2-18 i, 
argentea, (silver five-finger, w-y, Ju. %.) stem prostrate and ascending, rarely 
sub-erect, branching, white-downy; stipules ovate, acute; leaves wedge- 
form, gash-toothed, silvery white beneath, petals retuse, scarcely longer 
than the calyx, 4-10 i. 
B. Leaves pinnate. 
anserVna, (tansey cinquefoil, y. J. %..') creeping ; leaves interruptedly pinnate, 
numerous, gash-serrate, silky, white-downy beneath ; peduncles solitary, 
l-flowered. 
fruticosa, (shrubby cinquefoil, y. J. %^ stem fruticose, oblong, lanceolate, en- 
tire, approximate ; stipules lanceolate, membranous, acute ; flowers in co- 
rymbs, large; petals longer than the calyx. A shrub 2 feet high, much 
branched, hairy. Margin of swamps. 
C. Leaves ternate. 
tridenta'ta, (mountain cinquefoil, w. Ju. % ) smoothish, stem ascending, di- 
chotomous; leaves ternate-palmate ; leafets wedge-oblong, coriaceous, 3- 
toothed at the summit, pubescent beneath ; stipules lanceolate, acuminate ; 
corymb loose, few-flowered; petals oblong-ovate, longer than the calyx; 
stem 3-6 inches high. Mountains, Frozen regions to Car. 
norwe^gi'ca, (Norway cinquefoil, y. J. ©.) hirsute; stem erect, dichotomous 
above ; leaves ternate, palmate; leafets lance-rhombic, simply and doubly 
serrate; flowers numerous, sub-corymbed, and axillary; petals obcordate, 
shorter than the calyx. 8-10 i. Old fields. Can. to Car. 
POTERIUM. 19—13. (Rosacece.) [From poierion, a cup ; so called from the shape of tho 
flower.?.] 
sanguisor^ba, (burnet, J, %.) stem somewhat angled, unarmed ; leaves pin- 
nate ; leafets serrate ; flowers in heads. Ex. 
PRENANTIIES. 17—1. iCickoracecB.) [From pr-enes, drooping, and areZAos, flower.] 
al'ba, (white lettuce, w. p: Au. %.) radical leaves angled, hastate, toothed, 
somewhat lobed; cauline ones round-ovate, toothed, petioled; upper ones 
mostly lanceolate; panicle lax; the terminal fascicle nodding; calyx 8- 
cleft, 8-10-flowered. Var. nana, leaves 3-parted, hastate, ovate, and lan- 
ceolate, sometimes all simple ; racemes panicled or simple. 1-3 f. 
altis'^sima, (p. y. Au. %..) stem branching ; leaves petioled, 3-lobed, angled, 
denticulate ;* margin scabrous; racemes axillary; flowers nodding; calyx 
about 5-flowered. 
corda'ta, (w. y. Au. %.) stem panicled above ; leaves petioled, cordate, tooth- 
ed, ciliate ; floral ones sessile, oblong, entire ; panicle lax, raceme-flower- 
ed. 4-6 f. 
PRIMULA. 5—1. (PrimulacecB.) [From jor-mwi^s, the beginning, so called because it blos- 
soms in the beginning of spring. The natural family, Primulacese, is a division of Jussieu's 
order, Lysimachiae.] 
farino'sa, (bird's-eye primrose, p. % ) leaves obovate-spatulate, mealy beneath; 
umbel many-flowered ; peduncles spreading ; border of the corolla flat, as 
long as the tube, with obtuse, obcordate segments ; scape 6-10 i. Leaves 
all radical. 
