38 THE DISTRIBUTION OF EAST RIDING PLANTS. 



and R. Flammula, Nasturtium officinale, N. palustre, N. 

 sylvestre, Stellaria aquatica, Lychnis Flos-cuculi, Myrio- 

 phyllum alterniflorum, and M. verticillatum, Sium latifolium 

 and S. erectum, Qinanthe fistulosa, CE. Lachenalii and 

 CE. Phellandrium, Senecio aquaticus, Hottonia palustris, 

 Lysimachia Nummularia, Menyanthes trifoliata, Myosotis 

 palustris, and M. repens, Utricularia vulgaris, and U. Minor, 

 Mentha hirsuta, Lycopus europoeus, Hydrocaris Morsus-ranae, 

 Elodea canadensis, Stratiotes Aloides, Iris Pseudacorus, 

 Typha latifolia, and T. ang-ustifolia, Sparganium ramosum, 

 and S. simplex, Acorus Calamus, Lemna minor and the other 

 three species of duckweed, Alisma ranunculoides, Potamo- 

 geton natans, P. polygonifolius, P. perfoliatus, P. crispus, 

 P. densus, P. pectinatus, and P. flabellatus, Zannichellia 

 palustris, Phragmites communis, and Glyceria fiuitans. 



(c) Of marshy places, carrs, and ings, or damp grass 

 lands on the boulder clay, or clayey alluvium of Holderness 

 — not peat bogs, as these are now almost entirely absent 

 from this division — there is yet another group of aquatics, 

 or semi-aquatic species, almost as distinct as that under the 

 last sub-division (b). It includes Caltha palustris, Viola pal- 

 ustris, Stellaria palustris, Hypericum quadratum, Lathyrus 

 palustris, Lotus major, Potentilla palustris, Lythrum salicaria, 

 Lysimachia vulgaris, Menyanthes trifoliata, Pinguicula vul- 

 garis, Salix triandra and S. pentandra, Epipactis palustris, 

 Juncus communis, J. glaucus, J. acutiflorus, Scirpus pauci- 

 florus, Carex dioica, C. teretiuscula, C. paradoxa, C. paniculata, 

 C. muricata, C. filiformis, and C. vesicaria; of sedges, indeed, 

 a wonderfully fine array. Calamagrostis Epigejos, and C. 

 lanceolata, Lastrea Thelypteris, Equisetum palustre, and 

 E. limosum. 



(d) In marshy places in the Derwent district, the sandy 

 alluvial tract and the spring marshes at the foot of the Wolds, 

 although many of the hygrophiles in (r) are present, there 

 are also some members of the association never found in 

 Holderness. Such are, Sagina nodosa, Peplis Portula, 

 Hypericum elodes, Parnassia palustris (abundant also on 

 damp clay cliffs, but preferring the sandy or gravelly 

 bottomed marsh), Drosera rotundifolia, and t). intermedia, 

 Anagallis tenella, Gentiana Pneumonanthe, Limosella aqua- 

 tica, Mentha Pulegium, Litorella juncea, Salix repens, 

 Narthecium Ossifragum, Carex pulicaris, Osmunda regalis, 

 and Pilularia globulifera. 



