128 PORTULACCA-PRIMULA. 



PORTULACCA. 12—1. (Portulaccem.) | From porto, to carry, /ac, milk.] 

 olera'cea, (purslane, y. J. ©.) leaves wedge-form ; flowers sessile. 



POTAMOGETON. 4—4. (Junci.) [From potamos, a river, and geiton, adjacent, so called 

 because il grows about rivers.] 

 natans, (pond-weed, g. J. %.) leaves long-petioled, floating, lance-oval ; at 



first some are sub-cordate. On water. 

 fiuitans, (g. Ju. %..) lower leaves long, linear, upper ones lanceolate, nerved, 

 coriaceous ; all petioled. In water. 



POTENTILLA. 11 — 13. (Rosacea.) [From /joJeKZi'a, power, so named on account of its sup*- 

 posed power to heal diseases.] 



A. Leaves digitate. 



canaden"sis, (common five-finger, y. IM. 'Zj..) 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. 1|-.) 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. heaves pinnate. 



anseri'na, (tansey cinquefoil, y. J. %.) creeping ; leaves interruptedly pinnate, 

 numerous, gash-serrate, silky, white-downy beneath ; peduncles solitary, 

 1-flowered. 



fniticosa, (shrubby cinquefoil, y. J. 7^..) 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- 

 ehotomous; 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. 



nonoe'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 poterion, a cup ; so called from the shape of the 

 flowers.] 



sanguisor'ba, (burnet, J. %.) stem somewhat angled, unarmed ; leaves pin- 

 nate; leafets serrate ; flowers in heads. Ex. 

 PRENANTIIES. 17—1. iCichoracea.) [From ;jreraes, drooping, and an/ZiW, 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"siraa, (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. (Primulacers.') [From />n7?t2<fes, the beginning, so called because it blos- 

 soms in the beginning of spring. The natural family, Frimalacece, is a division of Jussieu'9 

 order, Lysimachise.] 



farino'sa, (bird's-eye primrose, p. 7}.) 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. 



