1921 



Index 



313 



implicatum, 228; uneiphylhnn, 



forma prost rat um, 228; virgatum, 



200, var. cubense, 156, 192, 200, 



in Michigan, 200; Walteri, 61; 



Werneri, 194; zonale, 53. 

 Panoxys, 39. 

 Parker, C. S., Lathyrus Nissolia, 



a recent Introduction in the 



State of Washington, 246. 

 Parmelia lophyrea, 183. 

 Parmeliopsis, 184. 

 Parnassia, 111. 

 Pease, A. S., Gray Pine and Arbor- 



Vitae, 247. 

 Peattie, D. C, An interesting 



Habitat, 69. 

 Pelexia cranichoides, 84; setacea, 



84. 

 Pellia epiphylla, 282. 

 Peltandra, 129. 

 Pennell, F. W., Veronica in North 



and South America, 1, 29. 

 Persicaria maculata, 258; major, 



258, 259; nodosa, 258; robustior, 



147; salicifolia, 259; tomentosa, 



259. 

 Petasites palmatus, 132, 298. 

 Petrocelis, 66. 

 Peutalis nodosa, 258. 

 Phymatolithon compactum, 67. 

 Pine, Grav, and Arbor-Vitae, 247; 



Jack, 200; Loblollv, 195; Red, 91; 



White, 91. 

 Pinus Banksiana, 130, 188, 247- 



249; divaricata, 188; resinosa, 



131, 188, 247; Strobus, 185. 

 Pinguicula, 111. 



Pitcher Plant, 148. 



Plagiochila Austini, 284. 



Plants, Preliminary Lists of New 



England, — XXVIII. 209; from 



Knox County, Maine, Some 



rare, 198; new to Rhode Island, 



Three, 27. 

 Platymonas, 249, 251, 252; sub- 



cordiformis, 249, 252, 256; 



tetrathele, 250, 252, 

 Plymouth Gentian, 160. 

 Poa, 133; angustifolia, var. costata, 



133; costata, 133, 139, 164, 



231, 300; pratensis, 133, subsp. 



costata, 133, var. costata, 133, 



var. depauperata, 133; saltuensis, 



231; trivialis, 231. 

 Pogonia, 141, 195-197; affinis, 



195-197, a new Station for, 195; 



ophioglossoides, 101, 102, 129, 



132, 140, var. brachypogon, 



245; verticillata, 76, 196, 197; 

 Whorled, 197. 



Polygonatum biflorum, 242. 



Polygonum, 165, 168; acadiense, 

 134, 165, 260; acre, 146, 260, 

 var. leptostachyum, 260; allo- 

 carpum, 151, 163, 262; aviculare, 

 261, e. buxifolium, 260, 262, 

 ft. latifolium, 261, 262; buxifol- 

 ium, 260-262; cuspidatum, 262; 

 erectum, 261; Fowleri, 198, 260- 

 262; hydropiperoides, 168, 260, 

 var. digitatum, 260; incanum, 

 259; lapathifolium, 258, 259; 

 subsp. maculatum, 258, var. 

 incanum, 259, var. maculatum, 

 258, var. nodosum, 258, var. 

 pecticale, 258, var. salicifolium, 

 259; littorale sitchense, 260; 

 littorale, (8. buxifolium, 260, 261; 

 maculatum, 258; maritimum, 260; 

 Muhlenbergii, 166, 259; nodosum, 

 258, 259, j£f. incanum, 259, forma 

 salicifolium, 259; pallidum, 259; 

 pennsylvanicum, 259, var., 



258; Persicaria * tomento- 

 sum, 259; polystachyum, 262; 

 punctatum, 146; punctatum ro- 

 bustior, 147; punctatum, var. 

 robustior, 146, 302; Raii, 150, 

 158, 260; robustius, 147, 149, 

 155, 166, 168, 260, 300; scabrum, 

 258, 259; tomentosum, 259, var. 

 incanum, 259. 



Polvpodium, 69, 149; vulgare, 147, 

 185. 



Polypremum procumbens, 40. 



Polystichum acrostichoides, 185; 

 Braunii, 136, 185. 



Polvtrichum, 110, 138, 142, 150, 

 235, 236, 244, 278, 286. 



Pontederia, 142. 



Potamogeton alpinus, 164, 189; 

 amplifolius, 189; angustifolius, 

 191; bupleuroides, 163, 191; con- 

 fervoides, 145, 149, 191; dimorph- 

 us, 191; filiformis, var. borealis, 

 191; Friesii, 191;gramineum, 189; 

 gramineus, 189-191, (i gramineus, 



189, «. graminifolius, 189, var. 

 graminifolius, 189-191, var. myrio- 

 phvllus, 189, var. spathulaeformis, 



190, 191; graminifolius, 189, 

 190; heterophyllus, 189, 190, 

 var. graminifolius, 189; monili- 

 formis, 191; natans, 189; Oak- 

 esianus, 146, 148, 163, 189, 

 pectinatus, 141, 192; perfoliatus; 



