202 
INDEX 
Populus nigra var. genuina io, n 
— — var. italica 9 
— — var. pubescens 10 
— — var. pyramidalis 9 
— — var. typica x var. italica 9 
— — var. viridis 10; plate 13 
— nivea 5 
— pannonica 9 
— pyramidalis 9 
— — x nigra 9 
— pyramidata 9 
— scythica 10 
— serotina 12 
x — — 11, 12, 94, 106; plate 15 
— steiniana 7 
— tacamahacca 13, 106; plate 17 
— thevistina 9 
— thracia 9 
— tremula 7, 8, 106; plates 6, 7, 8 
— — race typica 8 
— — race villosa 8 
— — var. dodiana 8 
— — var. genuina 8 
— — var. glabra 8 ; plates 7, 8 
— — var. sericea 8 ; plate 6 
— — var. villosa 8 
— viadri 10 
— virginiana n 
— vistulensis 10 
— villosa 8 
Portulaca 2 
Portulacaceae 1 
Portulaccales 150 
Potamogiton angustifolium 1 1 5 
Prickly saltwort 185; plates 192, 193, 194 
Primitive angiosperms 2, 3 
Primulaceae 1 
Primulales 150 
Pruinosae 58 
Prunus avium 106 
— domestica 106 
— laurocerasus 106 
— padus 106 
— spinosa 106 
Pseudo-Arthrocnemum (section of Sali- 
cornia) 187, 188, 189 
Pseudoblitum (section of Chenopodium) 
154. 163 
Pulchres (series of Rumex) 133, 142 
Purple Osier 65 ; plates 65, 66, 67 
Purpureae (series of Salix) 58, 65 
Purslane, Sea 180; plate 187; map 41 
Pyrus aucuparia 106 
— communis 106 
— domestica 106 
— malus 106 
— — var. americana 106 
Pyrola 1 
Quercus 71 , 72, 76, 78 
— alba 75 
— aurea 74 
— cerris 73; plate 72 
— — var. dentata 73 
— conglomerata 73 
— — var. aurea 73 
— esculus 74 
— femina 75 
— ilex 72 ; plate 7 1 
— intermedia 73 
— lanuginosa 74 
— latifolia 75 
— — mas quae brevi pediculo est 73 
— pedunculata 75, 76 
— — x sessilis 76 
— — var. pubescens 76 
— pubescens 74 
— — x sessiliflora 74 
— robori-germanica 76 
— robur 72, 73, 74, 75, 76, 106, 145; 
plate 76 
— — x sessilis 76 
— — subsp. pedunculata 75 
Quercus robur var. (3 73, 74 
— — var. pedunculata 75 
— — var. sessiliflora 73 
— — var. sessilis 73, 74 
— — x sessiliflora 73, 76; plate 77 
— — subsp. sessiliflora 73 
— rosacea 76 
— sessiliflora 73, 74, 75, 76, 145 ; plates 
73, 74, 75 
— — forma castanoides 74 
— — var. j 3 74 
— — var. genuina 74 
— — var. genuina subvar. sphaero- 
carpa 74 
— — var. macrocarpa 74 
— — var. montana 74 
— — var. pubescens 74 
— — var. pubescens forma longi- 
peduncula 74; plate 75 
— sessilis 73, 74 
— — var. glabra 76 
— subgermanico-robur 76 
— subrobori-germanica 76 
— vulgaris 75 
Ranunculaceae 3 
Ranunculus 1 
Repentes 48 
Retention of Linnaean trivials xv 
Reticulatae (series of Salix) 25 
Rhabarbareae 128 
Rhabarbarum 128 
Rhamnus catharticus 106 
Rheum 2, 128, 130 
— digynum 128, 129; plate 137; map 22 
Rhubarb, Monk’s 133; plate 141 ; map 23 
Ribes grossularia 106 
Robinia pseudacacia 106 
Robur (subsection of Quercus) 72, 73 
Roman nettle 100; plate 109 
— sorrel 131 ; plate 138 
Rosa canina 106 
Rosaceae 3 
Rosmarinifoliae (series of Salix) 29, 48 
Rugosae 51 
Rumex 2, 128, 130 
x — abortivus 144 
— acetosa 130, 131 ; plate 139 
— acetosella 130, 132 ; plate 140 
— — race angiocarpus 132 
— — var. angiocarpus 132 
— — var. gymnocarpus 132 
— acetoselloides 133 
— acutus 135, 141, 143, 146 
— — var. latifolius 135 
— alpinus 133, 155; plate 141; map 
2 3 
— aquaticus 134, 135, 136, 137, 143 
— — x hydrolapathum 135 
— — var. crispatus 136 
— — var. heterophyllus 135 
— aureus 149 
— britannicus 134 
— condylodes 143, 145, 146, 147 ; plate 
x 5° 
— — x crispus 145, 147 
— — x glomeratus 146 
— — x obtusiflorus 147 
— — x pulcher 147 
— — forma sanguinalis 146 
— confertus 138 
— conglomeratus 143, 144, 147 
— — x crispus 144 
— — x maritimus 144 
— — x maritimus x obtusifolius 148 
— — x obtusifolius 144 
— — x pulcher 144 
— — x sanguineus 146 
— — var. divaricatus 143 
— — var. pusillus 144 
— — var. pycnocarpus 143 
— — var. subsimplex 143 
— conspersus 137, 138 
Rumex crispus 136, 137, 138, 139, 140, 
141 ; plate 144 
— — x domesticus 137 
— — x glomeratus 144 
— — x longifolius 136, 137, 138 
— — x obtusifolius 140, 141, 148 
— — x pulcher 139 
— — x sanguineus 147 
— — var. elongatus 139 
— — var. planifolius 139 
— — var. subcordatus 138 
— — var. trigranulatus 138, 139; plate 
144 
— — var. typicus 136, 137, 138, 139, 
140, 147 ; plate 144 
— cristatus 14 1 
— digynus 128, 129 
— divaricatus 140, 143 
— domesticus 136 
— — x obtusifolius 137 
— — var. (3 136 
— — var. elongatus 136 
x — duffti 147 
— elongatus 136, 139, 140 
— — x obtusifolius 139 
— friesi 140 
— glaucus 131 
— glomeratus 143, 145, 146, 148; plate 
J 47 . 
— — x maritimus 144 
— — x obtusifolius 144 
— — x pulcher 144 
— — subvar. divaricatus 143 ; plate 
147 
— heterophyllus 135 
— hydrolapathum 134, 135, 136; plate 
142 ; map 24 
— — var. latifolius 134, 135; plate 
142 ; map 24 
— — var. vulgaris 134, 135; plate 142 
x — knafi 144 
— limosus 147, 148, 149; plate 151; 
map 28 
— — x maritimus 148 
— — x obtusifolius 148 
— — var. palustris 148; plate 15 1 
— — var. thuilleri 148 
— longifolius 133, 135, 136, 137, 138; 
plate 143 ; map 25 
— — x obtusifolius 136, 137 
— maritimus 147, 148, 149; plate 152; 
map 29 
— — forma warreni 144 
— — var. viridis 147 
— maximus 134, 135 
— multifidis 133 
x — mureti 144 
— nemolapathum 143, 144, 146 
— nemorosus 146 
— — x pulcher 147 
— obtusifolius 136, 138, 140, 141, 144, 
147 ; plate 145 
— — x palustris 148 
— — x pulcher 141 
— — x sanguineus 147 
— — race agrestis 140 
— — race silvestris 141 
— — subvar. purpureus 140 
— — var. agrestis 140 
— — var. discolor 140 
— — var. friesi 140 
— — var. macrocarpus 140, 141 ; 
plate 145 
— — var. microcarpus 140, 141 ; plate 
*45 
— — var purpurascens 140 
— — var. purpureus 140 
— — var. silvestris 14 1 
— oguliensis 141 
— palustris 147, 148 
— — x maritimus 148 
— patientia 135 
— pratensis 14 x, 148 
