PORTULACCA— POTENTILLA. 



147 



pvgma'ea, (Ap. ^).) leaves long-linear, , divisions of the calyx lance-linear; petals 

 'edge-form, obtuse, coriaceous, with the I orbicular, sub-entire, of the length of the 



oblong, much larger than the calvx. 6-18 i. 

 S. 



gramliJlo'ra,{y-'w. Ap. f? .) leaves wedge- 

 obovate, obtuse, under surface and branches 

 rufous-pubescent ; outer petals obovate, 

 much larger than the calyx. 18-24 i. S. 



PORTULACCA. 12—1. (Portulaccece.) [From 



porto, to carry, lac, milk.] 

 olcia'cea, (purslane, y. J. ^.) leaves 

 wedge-form ; flowers sessile. 



pilo'sa, (0.) leaves subulate, alternate ; 

 axils pilose ; flowers sessile, terminal. (S^. 

 POTAMOGE'TON. 4—4. (Junci.) [From 



potamos, a river, and geiton, adjacent, so 



called because it grows about rivers.] 

 7Lotans, (pond-weed, g. J. 2^.) leaves 

 iong-petioled, floating, lance-oval; at first 

 some are sub-cordate. On water. 



flui'lans, (g. Ju. IJ!.) lower leaves long, 

 linear, upper ones lanceolate, nerved, cori- 

 aceous ; all petioled. In water. 



helerophyVbim, (variegated pond-weed, 

 g. Ju. 2X.) upper leaves floating, coriaceous, 

 elliptical, petiolate, lower ones membranous, 

 linear-lanceolate, sessile. 



diversifo'lmm, (g. Ju. 2J[.) upper leaves 

 floating, elliptical, petiolate, 5-nerved, lower 

 ones filiform ; spike axillary, almost sessile, 

 few-flowered. \Vater. 



per folia! turn, (g. Ju, 2/.) leaves amplexi- 

 caui, cordate, ovate ; «pike few-flowered, 

 on a short peduncle "Water. 



lu'ccnx, (g. Au. 2^.) leaves ovate-lanceo- 

 late, petiolate, pellucid, and finely veined ; 

 epiko long, cylindrical. 



a-i>i"pum, (r-g. J. 11.) leaves lanceolate, 

 tapering, sessile, undulate, fierrate ; spike 

 o-iO flowered. Lakes. 



pectiJia'lvm, (g. J. 2^.) leaves setaceous, 

 distichus, alternate, sheathing; spikes ter- 

 minal, interrupted. 



gramin"enm, (grass pond-weed, g. Ju. 

 2^.) leaves linear, grass-like, alternate, ses- 

 sile ; stipules broad ; stem terete, sub-di- 

 chotomous. In July, some of these plants 

 begin to raise their spikes of unopened 

 flower-buds to the surface of the water ; as 

 eoon as the stigmas are fertilized by the 

 pollen, the spikes are again withdrawn, to 

 ripen the fruit under water; others succeed 

 them, and the process continues. 



compres" sum, (g. Ju. 2/.) leaves linear, 

 obtuse, ses.sile ; stem compressed ; spike 

 4-6 flowered. 



roster if o' Hum, (g-y. Au. 2^.) leaves alter- 

 nate, linear, closely sessile ; stem flexuous, 

 compres.scd, sub-alate ; branches axillary; 

 stipules lance-linear, acute ; spikes many 

 (20-40) flowered. 2 3 f. 



POTENTIL"LA. 11—12. {Rosacea.) [From 



potentia, power, so named on accoimt of its 



supposed power lo heal di.sease.s.] 

 A. Leaves diqitate. 



cavaden"si.^, (common five finger, y. M. 

 2i.) procumbent, 8ub-ratno.-o, whitish-silky ; Frozen regions to Car. 

 stipules ovate, gashed ; loaves wedge-ovate, I noncdgi'ca, (Norway cinquefoil, y. J. ©,) 

 gash-toothed ; stem ascending and creep- ! hirsute ; stem erect, dichotomous above ; 

 iug, hirsute ; peduncles sohtniy, elongated ; j leaves tornute, palmate; leafcis lanno 



gth 



ar<;en"tca, (silver five-finger, w-y. Ju. 21.) 

 stem prostrate and ascending, rarely sub- 

 erect, branching, white-downy; slipulep 

 ovate, acute ; leaves wedgc-ibrm, ga.sh- 

 toothed, silvery white beneath ; petals re 

 tuse, scarcely longer than the calyx. 4-10 i 



sivi"plcx, (y. Ap. 2^.) erect, simple, hir- 

 sute; leaves oblong-oval, coarsely toothed; 

 peduncles axiflary. solitary, long, 1-flow- 

 ered ; petals nearly round, obcordate, 

 longer than the calyx. 



sarmcnto'sa, (y. M. 2X) stem sarmentose , 

 leafets obovate, obtuse, serrate, glabrous 

 above, hirsute beneath ; petals roundish, 

 longer than the calyx. 



rcc"ta, (y. J. 2^.) erect; leaves in fives 

 and sevens ; leafets lanceolate, coarsely 

 toothed ; petals obcordate, larger than the 

 calyx ; corolla large, pale. 



B. Leaves pinnate, 

 anseri'na, (tansey cinquefoil. y. J. 2^.* 



creeping; leaves interruptedly pinnate 

 numerous, ga.sh-serrate, silky, white-downy 

 beneath ; peduncles solitary, 1-flowered. 



friUico'sa, (shrubby cinquefoil, y. J. 11.) 

 stem fruticose, oblong, lanceolate, entire, 

 approximate ; stipules lanceolate, membra- 

 nous, acute ; flowers in corymbs, large ; 

 petals longer than the calyx. A shrub 2 

 feet high, much branched, hairy. Margin 

 of swamps. 



penm^ylva^nica, (y. Ju. 2^.) erect, very 

 soft, somewhat whitish-viilose ; leafet.-i ob- 

 long, obtuse, sub-pinnatifid, woolly ; panicle 

 straight, many-flowered ; segments of the 

 calyx semi oval. 



svpi'na, (y. J. ^.) stem decumbent, di- 

 chotomous ; leafets oblong, incisely serrate ; 

 peduncles axillary, solitary, 1-flowered. 



argu'ta, (w. J. 11.) stem erect, pubes- 

 cent, vi.scous above ; leaves unequally pin- 

 nate ; leafets somewhat round-ovate, ob- 

 lique at the ba.se, doubly gash-toothed ; sti- 

 pules sub-entire ; calyx acute, somewhat 

 shorter than the corolla. 1-3 f. 



hitmifn'sa, (y. M.) leaves digitate, qui 

 nate ; leafets wedge-oblong, obtuse, gash- 

 toothed, white-tomentose beneath ; pcduu 

 cles short, filiform, procumbent. 4-5 i. S 



russellin'na, ( Tp.) the most beautiful spe 

 cies produces rich, dark, scarlet flowers. 

 A low shrubby plant. Ex. 



formo'sa, deep red or purple flowera 

 blossoming from May to August. Ex. 



C. Leaves ternate. 

 tridenta'ta, (mountain cinquefoil. ^v. Ju. 



2^.) smoothish; stem ascending, dichoto- 

 mous ; leaves ternate-palmate ; leafets 

 wedge-oblong, coriaceous, 3ioothed at the 



I summit, puhcsctiit beneath ; stipules lance- 

 olate, acuminate: corymb loose, few-flow- 



! ered ; Dctal-i oblont; ovate, longt^r than the 

 calyx ; stem 3 6 ih.'hos high. Mountains. 



