GENERAL INDEX 



307 



Hawkweed, 115, 220, 221. See 



Hieracium 

 Hawthorn : bud-scales, 61 ; fr., 193 ; 



suckers, 155 ; thorns, 140. See 



Cratcegus Oxyacantha 

 Hay, 20, 262 

 Hazel : bud-scales, 61 ; fls., 176 ; fr., 



187 ; infl., 180 ; oil of nut, 147 ; 



pollination, 167 ; -thickets, 269. 



See Corylus 

 Heartsease, 217 

 Heat : as a climatic factor, 9 ; effect 



on pis., 73 ; influence on vital 



functions, 6 ; rays, 65 

 Hfiath, 39 ; calcifuge, 89 ; mycorhiza 



of, 125 ; stomata, 40 ; type of leaf, 



43. See Erica 

 Heath, 15, 16 ; Calluna-, 230, 249, 



250, 252 ; grass-, 230, 249, 250 ; 



summit-, 251 

 Heather. See Calluna 

 Heather-moor, 230, 250, 252, 253, 



255 

 Hedera Helix, climbing roots, 119. 



See Ivy 



Hedge-mustard, honey, 172 

 Hedgerow plants : effect of weak 



light on, 72 ; list of, 292 

 Helianthemum Breweri, 209 ; gutta- 



tum, 213 

 Heliotropism, f68 ; in the hedgerow, 



292 



Helleborus, honey-leaf, 172 

 Helminthia echioides, 60, 115. See 



Oxtongue 

 Hemi-parasites : of meadow-land, 



263 ; of natural pasture, 257 

 Hemlock, 152 

 Henbane, fr., 187 

 Heradeum Sphondylium, pollination, 



170. See Hogweed 

 Herbaceous perennials, 58, 62, 109, 



113, 115, 145 

 Herbals, 217 

 Herb-Christopher, 217 ; -paris, 214; 



-Robert, 60, 217 

 Heterophylly, f51 

 Heterotrophie plants, 6, 123 

 Hieracium, 220 ; latex, 142 ; iricum, 



209 



Highlands, 12, 17, 21 

 High-moor, 246 

 Hip, 149, 184, 195 ; citric acid in, 



143 

 Hogweed : fls., 181 ; hydathodee, 28 ; 



pollination, 170. See Heradtum 

 Helens lanatus, 115 



Holly : bud-scales, 61 ; fr., *147 ; 

 leaf, relation between form and 

 function, 103 ; spines, 104, 139, 

 140 ; xerophytic chars, of, 30, 39 



Hollyhock, fr., 191 



Honckenya peploides, 114 



Honey : a source of alcohol, 151 ; con - 

 cealment in fls., 170, 172 ; position 

 in fls., 172, 173 ; protection of, 172 



Honey-dew, 134; -fls., 169; -glands. 

 * 169,* 170 



Honeysuckle : bud-scales, 61 ; direc- 

 tion of climbing, 116 ; honey, 173 ; 

 visits of insects to, 170. See 

 Lonicera 



Hook-climbers, 115 



Hop, 214 ; climbing pi., 116, *117 ; 

 fr., 194 ; pollination, 167. See 

 Humulus 



Hornbeam, fr., 194 



Hornwort. See Ceratophyttum 



Horse-chestnut : bud-scales, 61 ; fr.. 

 190 ; infl., 179 ; leaf-mosaic, 68 



Horse-radish, 151 



Horse-tail, 44, 62 



Hottonia, 56 ; brood-buds, 54 ; leaf- 

 form, 50 ; stem-structure, *48. 

 See Water- violet. 



Houseleek, 155, *156 



Humble bees, 171, 173 



Humidity, 9, 11. See Moisture 



Humous acids, 88, 94, 240, 244, 246, 

 249 



Humulus Lupulus, direction of twin- 

 ing, 116, *117 



Humus, 19, 83, 93 ; " artificial," 83 ; 

 mild, 94 ; of woods, 265 ; -soils, 

 properties of, 93 



Hyacinth, 63, 115 ; repr. by bulbs, 

 157 ; Roman, 143 



Hybrids, 221 



Hydathodes, t27, 29, 263 



Hydrocharis, 51, *54 



Hydrophilous pis., f 29 ; tropo- 

 phytes, 58, 62 



Hydrophytes, f29, f47 



Hydrophytic annuals, 59 



Hydroscopic water, 86 



Hymenoptera, 173 



Hypocotyl, 146 ; swollen, 111 



Ice Age, 209, 210, 212, 213 

 Iceland moss. See Cetraria 

 Igneous rocks, 82 

 Impatiens Noli-me-tangere: fr., 189; 



seeds, 196 ; fulva, 215 

 In-breeding, 165 



