GENERAL INDEX 
Hawkweed, 221. 
Hieracium 
Hawthorn: bud-scales, 61 ;: fr., 193; 
suckers, 155; thorns, 140. 
Crategus Oxyacantha 
Hay, 20, 262 
Hazel: bud-scales, 61; fls., 176; fr., 
187 ; infl., 180; oil of nut, 147; 
115, 220, 
See | 
See | 
pollination, 167; -thickets, 269. | 
| Honey-dew, 134; -fls., 169; -glands, 
See Corylus 
Heartsease, 217 
Heat: as a climatic factor, 9 ; effect 
307 
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 : asource of alcohol, 151; con - 
cealment in fls., 170, 172 ; position 
in fls., 172, 173 ; protection of, 172 
#169, 71:70 
_ Honeysuckle : bud-scales, 61; direc- 
on pls., 73; influence on vital | 
functions, 6 ; rays, 65 
Heath, 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- 
twm, 213 
Heliotropism, +68 ; in the hedgerow, 
292 
Hellcborus, honey-leaf, 172 
Helminthia echioides, 60, 115. See 
Oxtongue 
Hemi-parasites: of meadow-land, 
263 ; of natural pasture, 257 
Hemlock, 152 
Henbane, fr., 187 
Heracleum Sphondylium, pollination, 
170. See Hogweed 
Herbaceous perennials, 58, 62, 109, 
113, 115, 145 
Herbals, 217 
Herb-Christopher, 217 ; -paris, 214; 
-Robert, 60, 217 
Heterophylly, +51 
Heterotrophic plants, 6, 123 
Hieracium, 220 ; latex, 142 ; iricwm, 
209 
Highlands, 12, 17, 21 
High-moor, 246 
Hip, 149, 184, 195; citric acid in, 
143 
Hogweed : fls., 181 ; hydathodes. 28 ; 
pollination, 170. See Heracleuwm 
Helcus lanatus, 115 
tion of climbing, 116 ; honey, 173 ; 
visits of insects to, 170. See 
Lonicera 
Hook-climbers, 115 
Hop, 214; climbing pl., 116, *117 ; 
fr., 194; pollination, 167. See 
Humulus 
Hornbeam, fr., 194 
Hornwort. See Ceratophyllum 
_ 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 Lwpulus, 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, +27, 29, 263 
Hydrocharis, 51, *54 
Hydrophilous pls., 729; 
phytes, 58, 62 
Hydrophytes, +29, +47 
Hydrophytie annuals, 59 
tropo- 
_ Hydroscopie water, 86 
Hymenoptera, 173 
| Hypocotyl, 146 ; swollen, 111 
| Tee 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 
