APPENDIX C 533 



*Potamogeton, sp. : a common genus of native aquatics ; fruit 

 in various stages of development, to be preserved at various times 

 in summer, in spirit, 213. 



Potato (see Solanuni). 



Prunus Lauro-Cerasus, the common Cherry-Laurel of gardens : 

 leaf, fresh or in spirit, 134 ; glands on leaf, 142. 



*Prunus PaduSj Bird Cherry : flowers, 189. 



Primula sinensis, the common green-house Primula : leaf, 146 ; 

 flower, 190. 



* Primula vulgaris, the common Primrose : flower, 190. 



*Pteris aquilina, the Bracken Fern : apex of rhizome, 303 ; 

 rhizome, in spirit, 298. 



Ptilota, a genus of red Seaweeds, found growing on vertical 

 rock faces, between tide-marks, or on stems of Laminarias : to be 

 used fresh, if possible (p. 385). 



*Puccinia graminis (^Ecidium Berberidis\ the rust of Wheat, 

 and other Grasses : is now less common than formerly, but may 

 frequently be found as dark streaks on the leaf and stem of 

 Grasses ; while the secidium forms bright-coloured swollen patches 

 on the leaves of Berberis : to be used fresh, or after hardening in 

 alcohol (p. 462). 



*Pythium de Baryanum appears constantly on seedlings 

 of Cress, which are grown close together, and kept very damp 

 (p. 491). 



^Ranunculus acris, the common Buttercup : flower, 187. 



Ranunculus, sp. : stem, 79. 



Raphanus sativus, the garden Radish : root, 153. 



Rhododendron ferrugineum, Swiss Rhododendron : often grown 

 in botanic gardens ; 146. 



* Rhododendron persicum, the common Rhododendron of 

 gardens : pollen-tubes, fresh, 208. 



Riccia fluitans, a not uncommon Liverwort, found in fresh- 

 water pools, &c., together with Lemna, &c. (p. 362). 



*Ricinus communis, the Castor Oil plant : ripe seeds may be 

 obtained from seedsmen, 216 ; young stem, 79. 



Robinia Pseud- Acacia : stem, 75. 



Rosa, sp. : mature stems, 97 ; prickles,147. 



Rubus, sp. : mature stems, 97 ; prickles, 147. 



