CRAT^GUS 419 



CRAT^EGUS. THORNS. ROSACES. 



The thorns in cultivation are deciduous trees or shrubs, nearly always 

 more or less armed, sometimes very formidably, with spines. Some of 

 the species from the southern United States are inclined to be semi- 

 evergreen, but the only truly evergreen ones that have been included 

 in the genus are three species of the Pyracahtha group, which in this 

 work are treated as a separate genus (see PYRACANTHA). Crataegus is very 

 sparsely represented in China, Japan, the Himalaya, and in Western 

 N. America. About a dozen species occur in Europe and Asia Minor. 

 Most of the remainder are natives of Eastern and Central N. America, 

 where an extraordinary number of beautiful species exist. A curious 

 ignorance of the wealth of Crataegi in this region prevailed until the last 

 twenty years. Sargent, dealing with the genus in his great Silva of 

 North America, in 1892, described only fourteen species. Ten years 

 later, in a supplement, the number increased to eighty-four. A census 

 of American Crataegi made in Nov. 1911 at Kew, showed that 922 

 so-called species had by then been described by various authors. It 

 is scarcely credible that anything like so vast a number of genuine species 

 exist there. A great many can differ from each other scarcely more 

 than garden varieties of "apples do. The classification of the American 

 thorns must at present be regarded as in an uncertain state. The various 

 authors who have taken up the subject have each a different view as to 

 the limits and characters of the various sections, and there appears to 

 have been a lack of co-operation among them. Many of the species are 

 nevertheless very distinct as well as beautiful, and there is no doubt that 

 the future will see the garden value of the genus much enhanced. But at 

 present only the old and leading types can be satisfactorily dealt 

 with here. 



Leaves alternate, always toothed or lobed, often both; those of the 

 vigorous non-flowering shoots of the year being usually much larger and 

 broader at the base than those of the flowering shoots. They have also, 

 as a rule, much larger and more persistent stipules. The stipules of 

 Crataegus, however, vary so much, even on the same plant, that they do 

 not afford very good differentiating characters. Flowers J to f in. in 

 diameter; nearly always white, sometimes yellowish white, sometimes 

 red in garden varieties ; produced mostly in May and June, in flattish or 

 rounded corymbs at the end of short, leafy shoots, which spring from the 

 buds of the previous year's growths. In rare instances the flowers are 

 solitary. Petals and calyx-lobes five ; stamens five to twenty-five ; styles 

 one to five. Fruit a pome, consisting of a fleshy exterior, enclosing as 

 many bony nutlets as there are styles. The fruits are of various colours, 

 mostly red, but also black, yellow, and blue. 



The nearest ally to Cratoegus is Cotoneaster, which has, however, 

 entire leaves and no thorns. Mespilus is also allied, but has large, 

 solitary, scarcely stalked flowers, with long leaf-like lobes to the calyx. 

 (See also PVRACAXTHA.) 



The cultivation of the thorns presents no problems. They all like a 



