402 POLYANTHES, POTENTILLA. 



with 2 distant leaves, 1 or 2 flowered : leaves, lance-oval : lip fringed. 

 812 i. S. 



61. POLYANTHES. 10. 17. 



Exotir. 



tubero'sa '(tuberose. 4), flowers alternate, in pairs : rootlets tuberous : scape 

 scaly: leaves linear, long. Sweet scented. 



166. POLYGALA. 33. 35. 



paucifo'lia (flowering wintergreen. O. r. M. 4), small, large-flowered : stem 

 simple, erect, naked below : leaves ovate, acute, glabrous, noar the top of 

 the stem : flowers crested, terminal, about in threes. 3 4 i. 5. 

 stn"ega (seneca snake root, mountain flax. O. r. or w. J. > ), stem erect, simple, 

 laty: leaves alternate, lanceolate: spike terminal filiform: flowers alter- 

 nate, not crested. Var. albida, leaves lanceolate or oval : spike somewhat 

 crowded : flowers white, sub-sessile. 8 14 i. S. 



polyg"ama rubella of Wildenow (ground flower. O. p. J. 4), stems numerous : 

 leaves linear-oblong, alternate downwards : racemes terminal and lateral, 

 elongated ; flo\\ ors sessile : radical racemes procumbent, with apterous 

 flowers. 4 8 in. 



83. POLYGONUM. 12. 28. 



amcula're (knot-grass. O. w. M. 4), stamens 8, styles 3 : leaves lanceolate, 

 scabrous at the margin : stipules short, lacerate : stem procumbent : flowers 

 sub-sessile, axillary, minute. 6 12 i. S. 

 Exotic. 



fagop"yrum (buck-wheat, r-w. Ju. ), stamens 8; styles 3 ; racemes pani- 

 cled ; leaves heart sagittate ; stem erectish, unarmed ; angles of the seeds 

 equal. 12 f. 



211. POLYPODIUM. 55. 5. 



vulga're (polypod. O. Ju. 4), frond deeply pinnatifid ; divisions lance linear, 

 obtuse, crenulate, approximate, upper ones gradually smaller ; fruit dots 

 solitary ; root chaffy. 8 12 i. N. 



212. POLYTRICHUM. 56. 4. 



juniperi'num (hair-cap moss. O. M. 4), stem generally simple ; leaves lance 

 linear, entire, flattish, somewhat spreading ; the apophysis depressed. In 

 dry woods, &c. 



61. PONTEDERIA. 6. 17. 



corda'ta (pickerel weed. O. b. Ju. 4), leaves heart oblong, obtuse ; spike many 

 flowered, compact ; divisions of the corolla oblong. Var. angustifolia, leaves 

 elongated triangular, truncate and sub-cordate at the base. 1 2 f. 



208. POPULUS. 50. 99. 



trt,mulo'i(les, (white poplar, American aspen. E. Ap. ^ ), leaves heart roundish, 

 abruptly acuminate ; tooth serrulate, glabrous, a little pubescent at the mar- 

 gin, with two glands at the base on the upper side ; petioles compressed, in 

 the young state silky. 2030 f. 



Exotic. 



dilata'ta (lombardy poplar, italian poplar, Ap. > ), leaves glabrous both sides, 

 acuminate, serrate, deltoid, the breadth equal to or exceeding the length ; 

 branches erect, close to the stem. It is said no pistillate plant of this species 

 has been brought to America. Consequently no seeds are obtained from it, 

 and it has not been reproduced here from seed. 40 80 f. 

 121. PORTULACCA. 54. 86. 



dfra'cea (purslane. O. y. J. ), leaves wedge form ; flowers sessile. .5. 

 1113. POTENTILLA. 35. 92. 

 Leaves digitate in fives, rarely in sevens. 



canaden"sis (common five-finger. O. y. 31 4.), procumbent, sub-ramose, whitish 

 silky ; stipules ovate, gashed ; leaves wedge obovate, gash toothed ; stem 

 ascending, and creeping, hirsute ; peduncles solitary, elongated ; divisions 

 of the calyx lance linear ; petals orbicular, sub-entire, of the length of the 

 calyx. This plant is so long in flower, and assumes so many forms and sizes, 

 that students in botany often make several species of it. 218 i. S. 

 argen"tea (silver five-finger. O. w-y. Ju. 4), stem prostrate and ascending, 

 rarely sub-erect, branching, white downy ; stipules ovate acute ; leaves 



