1909] 
Pluchea camphorata, 229. 
Plum, Beach, 127, 132. 
Poa alpina, 89; eminens, 7; trivialis, 
89. 
Podophyllum, 44. 
Podostemon, 46. 
Pogonatum, 16. 
Pogonia, 79; ophioglossoides, 79, 92; 
verticillata, 79. 
Polanisia, 45. 
Polygala eruciata, 230. 
Polygonella articulata, 30. 
Polygonum arifolium, 7; exsertum, 
121; Fowleri, 13; hydropiperoides, 
230; Roberti, 93; sagittatum, 7; 
scandens, 7; viviparum, 93. 
Polystichum  acrostichoides, var. in- 
cisum, 35, 36, var. Schweinitzii, 
35, 36; Braunii, 86. 
Polytrichaceae, 16. 
Polytrichum, 16. 
Pontederia cordata, 129. 
Porella, 16. 
Portulaca, 44. 
Posidonia, 150; Caulini, 150. 
Potamogeton, 129, 206; americanus, 
206; amplifolius, 206; angustifolius, 
206; bupleuroides, 88, 206; crispus, 
206; dimorphus, 206; epihydrus, 
206; foliosus, 206; gemmiparus, 206; 
heterophyllus, 206, forma gramini- 
folius, 206, forma longipedunculatus, 
14, forma maximus, 14, 206, forma 
myriophyllus, 206; hybridus, 207; 
lateralis, 207; lucens. 207; mysti- 
eus, 207; natans, 207; X nitens, 207; 
Nuttali, 37; Nuttalli, 37; Oakesi- 
anus, 207; obtusifolius, 207; pecti- 
natus, 88; perfoliatus, 14; prae- 
longus, 207; pulcher, 207; pusillus, 
207, var. polyphyllus, 207, var. 
Sturrockii, 207, var. tenuissimus, 
208; Robbinsii, 208; X spathae- 
formis, 208;  strictifolius, 208; 
Vaseyi, 208; zosterifolius, 208. 
Potentilla, 1, 127, 152, 153; Anserina, 
1—8, 5, 6, 8, 47, 48, var. anserinoides, 
5, var. argentea, 8, var. concolor, 
5, 8, 9, 48, var. discolor, 8, var. 
Egedii, 2, 6, 9, var. grandis, 2, 7, 9, 
48, var. groenlandica, 2, 7, 8, var. 
hirsuta, 2, 5, var. holosericea, 8, in 
eastern America, Representatives 
of, 1, var. maoria, 2, 5, var. nuda, 
2, 5, var. sericea, 2, 5, 8, 48, var. 
unicolor, 8, var. vulgaris, 2, 3, 5, 8; 
anserinoides, 5; Argentina, 8; cana- 
densis, 153; canescens, 47; concolor, 
Index. 251 
8; Egedii, 6, 9; inclinata, 47; 
litoralis, 7; Nuttallii, 47; pacifica, 
7, 8, A7, 48; palustris, var. villosa, 
48; pumila, 152, 153, A color Form 
of, 152, forma leucantha, 152, forma 
ochroleuca, 153; recta, 179; sericea, 
8; verna, 153. 
Preliminary Lists of New England 
Plants,— XXIII. Cladoniaceae, 215. 
Prenanthes nana, 99; trifoliolata, 99. 
Prepinus, 170. 
Primrose, Evening, 199. 
Primula farinosa, var. macropoda, 97; 
mistassinica, 97. 
Proserpinaca palustris, 120, var. am- 
blyogona, 120, An inland variety 
of, 120. 
Prunus Gravesii, 49; 
maritima, 127. 
Ptilimnium capillaceum, 226, 229. 
Pubescent Variety of Aster dumosus, 31. 
Pyrethrum inodorum, var. salinum, 
239. 
Pyrola americana, 96; chlorantha, 96; 
minor, 13, 96; secunda, var. ob- 
tusata, 96. 
Pyrus americana, 94; arbutifolia, 47, 
var. atropurpurea, 94, 231, 232; 
melanocarpa, 94; sitchensis, 94. 
Mahaleb, 49; 
Racomitrium, 16. 
Radiola, 50; Linoides, 50. 
Radula, 16. 
Ranunculaceae, 130, 132. 
Ranunculus repens, 93, 130. 
Raphanus, 45. 
Raspberry, 28, 236. 
Recent nomenclatorial Changes in the 
Genus Corallorrhiza, 102. 
Recognition of Corylus rostrata and 
Corylus americana, 107. 
Red Alga, 17; Pine, 21. 
Rehder, A., Note on the Morphology 
of Lonicera caerulea, 209. 
Reinschia, 63. 
Remarkable Form of Kalmia latifolia, 
199. 
Reports on the Flora of the Boston 
District,— IV, 75, V, 204. 
Representatives of Potentilla Anserina 
in eastern America, 1. 
Rhamnus alnifolia, 96. 
Rhododendreae, 53. 
Rhododendron canadense, 96; lapponi- 
cum, 97; viscosum, 231. 
Rhodora, 173-177, Account of certain 
ariet т Features in the Habitat 
of, 173. 
