GRASSLAND ASSOCIATIONS 263 
grassland are: Lolium perenne (perennial r ye-grass), 
Anthoxanthum odoratum (sweet vernal-grass), Dactylis 
glomerata (cock’s-foot), Poa pratensis and P. trivialis 
(smooth and rough meadow-grasses), Alopecurus pratensis 
(fox-tail), Phleum pratense (Timothy-grass), Agrostis alba 
(white bent-grass), Holcus lanatus (Yorkshire-fog), Cyno- 
surus cristatus (crested dog’s-tail), Festuca pratensis 
(meadow-fescue), and F. ovina (sheep’s-fescue). With 
these grasses are mixed intentionally certain leguminous 
plants—e.g., clovers—and on dry pastures these form a 
large percentage of the seed sown. 
Weeds of Meadow-Land.—The character of the weeds 
in the meadow depends largely on the chemical and 
physical nature of the soil. The plants are tall-growing 
and, protected by the surrounding grasses, are mesophytic, 
with large thin leaves. Transpiration is often difficult, 
owing to the humid atmosphere, and many of the plants 
possess hydathodes (p. 27), by means of which the water 
is got rid of in a liquid form. Sazifraga granulata ex- 
hibits such a character in a pronounced degree; the 
water which is excreted contains a large amount of 
calcium carbonate, which is left behind on the leaf as a 
white chalky deposit when the water evaporates. They 
are for this reason often called chalk-glands. As in the 
natural pasture, competition is very keen, and all the 
weeds are perennial or hemi-parasites—e.g., Rhinanthus 
and Bartsia. 
On damp, heavy soil the commonest weeds are: Rumex 
Acetosa (sorrel), R. crispus (dock), Ranunculus repens 
(creeping buttercup), R. bulbosus (bulbous buttercup). 
Plantago lanceolata (ribwort-plantain), Cardwus palustris 
(marsh-thistle), Senecio vulgaris (groundsel), S. Jacobecu 
(ragwort), Orchis mascula (early purple orchid), Traga- 
pogon pratensis (goat’s-beard), Prunella vulgaris (self-heal), 
Lapsana communis (nipplewort), Lathyrus pratensis (yellow 
meadow-vetchling), Cardamine pratensis (cuckoo-flower), 
Geranium pratense (meadow crane’s-bill), Spirea Ulmaria 
(meadow-sweet), Saxifraga granulata (meadow-saxifrage) ; 
and the rare Crocus vernus, Fritillaria Meleagris (snake’s - 
head), and Colchicum autumnale (autumn-crocus, meadow- 
saffron). Rhinanthus Crista-galli (yellow rattle) is found 
in almost ail meadows on clay land. 
In low-lying meadows near rivers the water-level is 
