12 



NOTES ON BEITISH PLANTS. 



No. 1. — CRATiBGUs OxYACANTHOiDES, TliuiL and C. MONOGYNA, Jacq. 



By C. p. Hobkirk. 



The two forms of Cratcegu^, liave for a long time been the subject of 

 observations, which in some quarters have been renewed year by year, and it 

 is with a view of calling the attention of our English local botanists to their 

 distribution in this country that I have been led to put together these few 

 notes on the subject. 



In many works on English botany the common hawthorn is generally 

 given as C. oxyacantha, L. under which term are united two very distinct 

 forms, viz. : — C. oxyacantlioides, Thuil. and C. monogyna, Jacq. 



Many continental authors as Koch, Eries, Doll, Kirschleger, de Brebis- 

 gon, Crepin, Des Moulins, Grenier, Boreau &c., are in favour of considering 

 the two forms as specifically distinct, whilst others, as Cosson and Germaiuj 

 Moris, Caruel, Wesmael &c. , and the greater proportion of our English • 

 botanists rank them merely as varieties of the same species. 



Prof. Babingtoti (Manual ed 5. p. 116,) gives theni as varieties, regarding 

 C. oxyacantha, as the typical form apparently, and stating ^. monogyna^ 

 to be " the more common form." 



The following diagnosis of the two forms is translated from Boreau's 

 " Elore du Centre" (vol. ii., p. 234) : — 



" C. oxyacantlioides, Thuill, ! flor. par. p. 245. 0. o^AyacantJia, Jacq. non L. — 

 Tufted slirub, leaves oboval ordinarily with three not deeply cut inciso-dentate lobes, 

 glabrous, of a deep shining green colour, with converging nerves ; corymbs lateral wnth 

 glabrous peduncles, calyx teeth oval ; styles two ; fruit red, enclosing two nuts. 

 Flowers white ; beginning of May." 



'* C. monogyna, Jacq., C. oxyacantha, L., sp. 683i A much branched shrub, often 

 passing into an arborescent form, leaves cuneiform oboval, deeply divided into three or 

 five inciso-dentate lobes, of a light green colour ; with both the nerves and lobes diver- 

 gent ; corymbs lateral, generally pubescent ; calyx teeth lanceolate ; for the most part 

 the flowers have only one style ; fruit red, rarely yellow, with one nut. Flowei's white, 

 somewhat rarely rose-coloured. " 



M. Boreau, further remarks, that " besides the very important character 



of the direction of the nerves, the latter species is easily distinguished from 



IliG preceding, by its smaller and less shining leaves, which are more deeply 



