FLOWERS OF THE HEATHS AND MOORS 



187 



regions, where few or no annual plants are 

 known. As has been seen the period of flower- 

 ing is indeed very late, and the interval between 

 this period and winter is relatively very short; 

 the uniformly perennial character of bog and 

 marsh vegetation is therefore a natural char- 

 acteristic. A few, as Cranberry, Rosemary, 

 Bog Myrtle, are shrubs, and the Alder and 

 the Willows are trees. The only annual 

 is Marsh Lousewort, a hemi-parasite on Grass 

 roots. 



The Pollination of Bog and Marsh Plants. 

 As might naturally be expected in the case 

 of habitats so essentially moist as bogs and 

 marshes, insects that get their livelihood in 

 the imago stage are not conspicuously abun- 

 dant. None the less many bog- and marsh- 

 plants rely upon insect agency for effective 

 crossing. 



Such are Great Spearwort, Marsh Marigold, 

 Grass of Parnassus, the Sundew, Water Drop- 

 wort, Valerian, Cranberry, Rosemary, Water 

 Violet, Bog Bean, Bog Speedwell, Marsh Red 

 Rattle, Bladderwort, Butterwort, Marsh Helle- 

 borine, Bog Asphodel ; the Bog Pimpernel, 

 which grows almost covered up by other 

 plants, making it difficult to discover it, is 

 normally self-pollinated. 



Golden Dock and Bog Myrtle are pollinated 

 by the agency of the wind, as are all the Rush, 

 Sedge, and Grass types that occur. 



The Dispersal of Seeds of Bog and Marsh 

 Plants. The uniformity of the bogs and 

 marshes as a whole is a factor in the mode 

 of dispersal of the seeds, the wind playing an 

 important part generally. 



The Great Spearwort, Sundew, Bog Pimper- 

 nel, Marsh Red Rattle (in part), Butterwort, 

 Jointed Rush, Galingale, Common Spike Rush, 

 Great Prickly Twig Rush, Hummock Sedge, 



Great Prickly Sedge rely upon their own 

 special mechanisms for the dispersal of the 

 seeds at no great distance from the plant. 



Animals, especially birds, disperse the berries 

 of the Cranberry and the Bog Myrtle. Water 

 is responsible for the dispersal of the seeds of 

 the Water Violet and the Bladderwort. 



The Fungal Pests of Bogs and Marshes. 

 As has been noted elsewhere, a damp habitat 

 is not, as a whole, conducive to attack by 

 fungi. There are some few paludal types of 

 fungi, but they are not of frequent occurrence; 

 and though moulds attack the tissues of plants 

 in moist situations, when they have been al- 

 ready subjected to adverse conditions, plants 

 in a healthy state are not usually infected. 

 The fungi that infest bog and marsh plants 

 belong chiefly to the smaller parasitic types, 

 mainly rusts, smuts, mildews, and moulds. 



Methods of Survey. In some respects the 

 bog and marsh are difficult to study on a sys- 

 tematic plan ; for the peaty soil and wet condi- 

 tions render both inaccessible for a large part 

 of the year, and the vegetation is so close and 

 tall, that anything like the detailed survey 

 recommended for meadows, woods, the corn- 

 field, coast, &c., is rendered difficult. But 

 the frequent arrangement of the plants in 

 wide associations is a feature which renders the 

 survey less formidable than at first appears. 



Attention ought to be paid especially to the 

 soil, depth of peat, nature of the water, &c., 

 and these conditions should be correlated with 

 the adaptations of the plants to xeromorphic 

 conditions. Otherwise surveys may be made 

 as in the case of a meadow. 



In the marsh the tree associations may be 

 noted first, and then the scrub. The dominant 

 types and larger associations should be mapped 

 out on a broad basis. 



SECTION XI 



FLOWERS OF THE HEATHS AND MOORS 



Heaths and Moors. In Section VIII some 

 remarks have been made as to the similar 

 character of Bogs, Heaths, and Moors, and 

 the natural passage of one of them into the 

 others has been pointed out in Sections I-III 

 and V-VIII. Heaths in the usual sense are 

 lowland, and drier than moors, and are usually 

 developed upon a sandy or gravelly soil. Even 

 in the uplands a heath only merges into moor- 

 land vegetation where the surface forms hollows 



and thick peat accumulates. A moor requires 

 no surface soil of a particular character, but 

 it does demand a certain sort of water, acid in 

 character. 



The peat of a heath is also acid, but relatively 

 dry. Occasionally there is a thick impervious 

 layer of sand and gravel (moor pan), which 

 is cemented together by mineral solutions 

 derived from the peaty soil. In the case of 

 a wet heath there is a deeper layer of peat, 



