HOBKIRK : CRATAEGUS. 



IS 



cut, and its smaller fruit, and flowers, the latter opening fifteen days later " 

 [than C. oxyacantlioides.'\ 



This character of the later opening of the flowers, is further insisted on 

 as a most important " biological difference", by Prof. Crepin (Bulletins de la 

 Societe Royale de Botanique de la Belgique vol. ii. p. 262 et seq.) He says : 

 — " I have recognised two forms apparently well distinguished by several 

 organic characters, and above all by a biological difference, which certainly 

 should cause some hesitation with those who are inclined towards a reduction 

 of species. In the Famenne I have always remarked that C. oxyacantlia, 

 had already flowered and commenced leafing, when (7. monogij7ia, had 

 scarcely opened either flower or leaf-buds, and that, in the same locaUty and 



soil, and under the same exposure The flowering of C. monogyna is 



from eight to twelve days later." Prof Babington, (Manual) takes no note 

 whatever of this difference in time of flowering, nor yet of the different 

 direction of the veins of the leaves, whilst Hooker and Arnott (British Plora, 

 Ed. 8. p. 140.) remark simply that the species is " variable in the form of its 

 leaves, in the downiness of the calyx, and in the colour of the flower and 

 fruit," thus evidently ignoring the existence of these two distinct forms. 



Alexander Irvine (British Plants, p. 613, 1858,) notices the /(2^(3r flower- 

 ing of his var. /3. oxijacanthoides, which is evidently a mistake, as by his 

 description, this is Thuillier's plant which other authors state to be the 

 earlier one in flower. His variety a. vulgaris, is evidently C. monogyna, 

 Jacq., though he makes no mention of the direction of the nerves of the 

 leaf. This seems a very marked character, if persistent, as it gives quite a 

 different form to the leaf, and it should be carefully examined, in order to 

 ascertain if the converging nerves are always present along with glabrous 

 peduncles, oval calyx teeth, and a double nutted fruit, whilst diverging 

 nerves and lobes are persistent with the opposite chara"ters of monogyna. 



In the new Edition of " English Botany" edited by Mr. Boswell-Syme, 

 are two excellent figures of these forms, but in the diagram of the leaf of 

 G. oxyacantJioides f. 479, the principal nerves of the lower lobes are 

 made somewhat divergent at their tips, which is scarcely the case in a speci- 

 men I have of this plant, gathered by Mr. Syme himself, at Hampstead, and 

 kindly sent me by Mr. J. G. Baker, of the Kew Herbarium : and further 

 Mr. Syme makes no mention of the direction of the nerves in his 

 description of either plant merely stating that the leaves of C. 

 oxyacantJioides, have the " margins slightly convex from the base to 

 the apex of the first lobe " (vol. iii, p. 236) ; and of C. monogyna^ 



