REPORT OF THE STATE BOTANIST 1904 7 



In order to collect typical flowering specimens of as many of 

 these species as possible, this prolific locality was visited in the 

 flowering time of these plants and specimens were collected. It 

 was again visited in autumn and a corresponding set of fruiting 

 specimens was collected, so that now most of the Rochester species 

 are well and, we believe, correctly represented in the state her- 

 barium. These specimens will serve as a standard with which to 

 compare specimens of closely related species collected in other 

 localities. They exhibit the specific characters in some respects 

 with greater precision than the words of descriptions can do. 



It has been observed that there is some variability in the fruit 

 of some species even on the same shrub. The fruit on a certain 

 shrub of Crataegus delucida in 1903 was small, irregu- 

 lar and "wormy." The present ^'•ear it was noticeably larger, fair 

 and sound. The fruit of the Graves thorn, C. gravesii, 

 which is produced by a clump of bushes near North Albany, is 

 variegated when mature and ripening, dull red and green colors 

 being intermingled. Three years in succession this clump has 

 borne fruit of this character. Its failure to ripen its fruit evenly 

 is due to the attacks of a parasitic fungus related to, if not the same 

 species as, the one that causes apple scab on apples. A clump of 

 bushes of the same species growing in Tivoli hollow bears fruit that 

 is fair and uniformly colored when ripe. It appears to be exempt 

 from the attacks of the fungus. The fruit on some plants has been 

 more persistent this year than it was last year. This is perhaps 

 largely due to the absence of many of the insects that usually prey 

 on thorn apples. It is probably also due in part to favorable 

 weather conditions. A plentiful supply of moisture has enabled 

 the plants to maintain their growth and vigor late in the season. 

 The more vigorous the plant the stronger its tendency to hold its 

 foliage and fruit. In some species the fruit regularly persists long 

 after the leaves have fallen. 



The tendency of numerous species to crowd together in certain 

 localities is a noticeable character in these plants. It is not uncom- 

 mon to find two and three species growing close to each other and 

 intermingling their branches so intimately as to appear at first 

 sight to be a single intricately branched individual. If specimens 

 for the herbarium are taken from such a clump great confusion and 

 perplexity is likely to result unless the greatest care is taken not 

 to mingle samples from different species. But association on a 

 larger scale excites our wonder. That there should be 41 species 

 of Crataegus growing spontaneously in the parks of the city of 

 Rochester and in its immediate vicinity is a remarkable fact. On 



