FLORAL CHARACTERISTICS. 27 



Watson, in his Cybele Britannica, was one of the first to 

 systematise the distribution of plants in the British Islands. 

 Considering the Flora, first of all, with reference to the climate, 

 he arranged it under two regions, called respectively the 

 Agrarian and the Arctic, each containing three zones, rising 

 in altitude, and distinguished by the presence or absence of 

 certain well-known plant forms. Following his arrangement, 

 the lowest Agrarian zone is marked by the presence of the 

 southern-type plants, Clematis vitalba, Rubia pereyrina and 

 Cyperus longus ; the mid- Agrarian zone by the absence of these 

 species, but the presence still of Rhamnus catharticus ; the 

 highest Agrarian zone by the absence of Rhamnus, but the 

 presence of Pteris aquilina. The lowest Arctic zone is, in its 

 turn, distinguished by Erica tetralix, without Pteris ; the mid- 

 Arctic zone by Calluna vulgaris, without Erica ; and the 

 highest Arctic zone by Salix herbacea, without Calluna.* 



As will be seen from the first record in the Flora, the 

 district of Harleston lies in the lowest Agrarian zone ; though 

 Rubia and Cyperus are not found in the neighbourhood, 

 Clematis is decidedly frequent. In fact, all the country south 

 of the Humber and the Dee, or an imaginary line drawn from 

 Liverpool to Hull, is included in this lowest zone, except the 

 mountainous tracts of Wales, and the high moors of the Severn 

 provinces. The following plants found in the Harleston dis- 

 trict are, in most cases, generally distributed throughout the 

 zone to which it belongs, but are unknown as natives in the 

 mid- Agrarian zone immediately above it : Helleborus fcetidus, 

 Aconitum napellus, Trifolium glomeratum, Trifolium suffo- 

 catum, Latliyrus aphaca, Tilloea muscosa, GEnanthe Jluviatilis, 

 Fceniculum vulgare, Galium anglicum, Linaria spuria, Cheno- 

 podium hybridism, Rumex pulcher, Carpinus Betulus, Ruscus 

 aculeatus, Fritillaria meleagris, Ornithogalum pyrenaicum, 

 Tulipa sylvestris, Alopecurus fulvus; while the following 

 denizens are absent in the succeeding zone : Adonis autumnalis, 

 Erysimum cheiranthoides, Verbascum Blattaria, Setaria viridis. 

 No mention is here made of the more local species which are 

 enumerated under the next section. 



Mr. Cottrell Watson then proceeds to resolve the British 

 Flora into types with reference to geographical position. 



1. The British Type includes thirty-four species of plants 

 thoroughly native to our island, though not to be considered 

 necessarily of sole British origin. All of these the Harleston 

 Flora possesses. 



2. The English Type includes thirteen species adapted to 



* Cf. Cybele Britannica, vol. i., p. 40; Compendium of the Cybele, pp. 

 1432. 



