S3 2 



NOTE— FUNGI. 

 'Large Fairy Rings at Fillingham Castle, Lincolnshire.'— It is 



very unusual to see 'fairy rinses' attain so great a circumference as 

 mentioned by Mr. Burton in last month's ' Naturalist.' It is stated that 

 these 'rings' commence to form from a common centre, which no doubt 

 they do. Year after year the circle is enlarged as the mycelium of the 

 fungus travels radially further atield. Probably, as the mycelium exhausts 

 the soil of food suitable to itself, it continues to advance in search of more, 

 and thus extends its sphere of operations. If we may judge from the robust 

 look of the grass forming the rings, the presence of the mycelium amongst 

 its roots does not appear to exercise any injurious effect upon it. On the 

 contrary, may it not render some of the soil contents more suitable for 

 absorption by the grass roots, and thus be of real benefit to them? 



Some able student might work out this problem, if it has not already 

 been done, as probably it has. At any rate, it would be interesting if some 

 one favourably located would take the trouble to note the annual increase 

 of diameter made in a few such rings, also whether any other kind of 

 Agarics inhabited them besides Marasmius arcades. Other observations, if 

 accurately taken— such, for instance, as altitude, level or incline of field 

 (pasture or meadow), open or shaded, moist or dry, kind of soil, etc. — would 

 add to the interest. — C. Crossland, Halifax, 3rd October 1900. 



NOTES— FLOWERING PLANTS. 



Alien Plants: a Query. — In regard to the list of alien plants in 

 Lincolnshire, it would interest some of your botanical readers to know on 

 what grounds Mr. Woodruffe- Peacock names as Alien (see Oct. number of 

 'The Naturalist') Lepidium rude rale and Chenopodium vulvaria. In J. E. 

 Smith's botany they are not marked ' vix indigena,' his usual phrase when 

 doubtfully native. Smith's references of these two species are to Hudson, 

 Ray (1790), and Withering. — H. Payne, Newhill Hall, 3rd October [900. 



Alien : A Definition. — The late Hewett Cottrell Watson's definitions 

 of Denizen, Colonist, and Alien are what all botanists use in Britain, and 

 far beyond our shores. They are from the ' Cybele Britannica,' and run as 

 follows : — 



'A Denizen is a species suspected to have been introduced by man, and 

 which maintains its habitat. 



'A Colonist \s one found only in ground adapted by man for its g-rowth 

 and continuous maintenance. 



' An Alien has presumably been introduced by human agency.' 



These general rules cannot, however, be followed without careful con- 

 sideration in any particular case. A plant may be a Native of England and 

 Alien in any given spot. Trifoliuin ocliroleucon is such if found anywhere 

 except in the eastern counties south of the Humber. A species may be 

 Native on a given soil and Alien if found growing on others in a given 

 county. Trifoliuin ocliroleucon is Native on the boulder-clay soils in Lincoln- 

 shire, and Alien elsewhere ; while Potentilla argentea is only Native on the 

 Spilsby sandstone. In this county, too, Afropa, Hyoscyamus, and the 

 Verbascums, with a larg-e number of others, are most certainly Denizens. 

 All the Papaver, Diplotaxis, and Erysimum are Colonists. Quite a vast 

 number are Alien, for the sake of example, Vicia lutea, V. Icevigata, 

 V. hybrida, Caucalis la ti folia, C. daucoides, Mentha viridis, and Salvia 

 pratensis. To this latter class belong Chenopodium pseudo-botryoides and 

 C. vulvaria, Fceniculum and the Lepidiums I named in a short list on 

 p. 299 of 'The Naturalist ' for 1900. They are only found at Grimsby on 

 made ground with scores of foreign Aliens, many of which still require 

 naming, quite away from their native habitats. After using the Drift Maps 

 for ten years, and studying species wholly from the point of view of soils in 

 botanising, I am generally in a position now to say where a species can 

 grow naturally and where it cannot on the soils of Lincolnshire. — E. Adrian 

 Woodruffe-Peacock, Cadney, Brigg, Lincolnshire, 20th Octob er iqqo. 



Naturalist, 



