The Romance of our Hawthorns 



By John Dunbar, KS* 



SOMETHING ABOUT THE DISCOVERY OF A HOST OF SPLENDID 

 HARDY NATIVE TREES THAT HAVE MASSES OF FLOWERS 

 AND SHOWY FRUITS — THEIR POSSIBILITIES FOR GARDENS 



(Editor's Note. — Our native hawthorns have so far been but little appreciated as garden possibilities and the almost sudden realization that instead of a mere 

 handful of species there were perhaps a thousand seemed likely to put off still longer a real popular appreciation of these rugged, sturdy trees. It is fortunate then 

 that these plants have been studied horliculturally by Mr. Dunbar in the parks of Rochester, keeping pace with the botanists' researches. Indeed, Mr. Dunbar and 

 Professor Sargent have worked together and in presenting this crystal ization of his studies to a dozen kinds having the most garden or landscape merit Mr. 

 Dunbar has rendered a great service to a future generation of planters.) 



TWENTY years ago there were 

 generally recognized fourteen 

 species and a few supposed vari- 

 eties of American hawthorns; at 

 the present time there are approximately 

 nine hundred species known to science. 

 No story in the botanical and horticultural 

 features of the North American continent 

 has been more interesting during the past 

 dozen years than the investigation and 

 discovery of these numerous new plants 

 which had all the time been growing 

 right under our very eyes. 



Some twenty-five to thirty years ago, 

 Dr. C. S. Sargent, Director of the Arnold 

 Arboretum, Harvard University, received 

 large quantities of American hawthorn 

 seeds, from different parts of the North 

 American continent (but they came mostly 

 from George Letterman, Newport, Ark.,) 

 Those seeds were sent under numbers 

 and records, and the individuals from 

 which the seeds were collected were 

 known. About 1896, when these 

 seedlings began to flower and 

 fruit, Dr. Sargent's interest was , r 



roused by the fact that they 

 differed constantly from any 

 of the described and known 

 species. It was observed, 

 for instance, that different 

 plants, which it had been 

 supposed belonged to one 

 species, differed in time of 

 blooming, in the number of 

 stamens, color of anthers, 

 periods of ripening the fruit, 

 as well as in the formation 

 and texture of the fruit 

 and shape of the nutlets. 

 The conclusion forced itself 

 on Doctor Sargent's mind, 

 that these characters were 

 constant and could be de- 

 pended on as distinguishing 

 specific features. It might be 

 said here, that Doctor Sargent 

 had prejudices to the contrary 

 view, but he could not shut his 

 eyes to facts which stared him in 

 the face. He immediately went to 

 work, and with the assistance of a num- 

 ber of collaborators, made collections " of 

 hawthorns from Quebec to Florida under 

 rigidly careful numbers, records and ob- 

 servations from individual trees and bushes, 

 upon which the descriptions were based and 

 from which seeds were also gathered and 



sowed, and these young plants are now 

 growing in the Arboretum. In the progeny, 

 which so far has flowered and fruited, all 

 evidence has pointed to the fact that they 

 are true to the parents in all specific 

 characters. 



The question naturally arises in the minds 

 of some people, how it came about that so 

 many new species were observed and 

 brought to light in such a short time, 

 when men like Torrey, Gray, Engelmann, 

 and others failed to notice them. It may 

 be said perhaps, that these men were 

 largely dealing in pioneer work, and did 



Specimen native hawthorn left when clearing ofl 

 the ground on the estate of Mr. Bayard Thayer, at 

 South Lancaster. Mass. Could anything be prettier? 



189 



not have much time to specialize with cer- 

 tain families of plants, as they were dealing 

 most of their lives with vast aggregates. 

 This is an era of specialization in all scien- 

 tific studies, botany included, and it is 

 practically impossible to-day, in the keen 

 searching tests applied in botanical investi- 

 gation, for a man to have an exact knowl- 

 edge of any genus of plants that contains 

 a considerable number of species, without 

 having given it keen observation for a 

 number of years in the field, herbarium, 

 germination of seedling, study of the 

 progeny in relation to the parents, and 

 other details. The investigator who has 

 done this is walking over a field every foot 

 of which he knows thoroughly. When 

 certain observers who have given the genus 

 no special investigation, mildly ridicule the 

 making of so many new species of haw- 

 thorn, their criticisms surely have no 

 relevancy. 



The American hawthorns, as at 

 present understood and interpre- 

 ted, fall into twenty-one natural 

 groups, and the different in- 

 dividuals in those various 

 groups can be recognized 

 by an expert at a glance. 

 Botanists, however, with 

 broad ideas in regard to 

 the limitation of species, 

 are inclined to regard 

 those twenty-one groups 

 as twenty-one distinct 

 species; and when they are 

 confronted with those 

 numerous forms that sur- 

 round and group them- 

 selves with those types; 

 they regard them as 

 varieties. 

 Other botanists, who 

 have investigated the 

 American hawthorn on the 

 most rigid scientific lines, have 

 been forced to the conclusion 

 that they are distinct and true 

 species. A species, as we under- 

 stand it, is "a unit composed of a 

 number of individuals which repro- 

 duces itself from seed, with definite 

 constant characters, within certain limited 

 variation," and it has been abundantly 

 demonstrated that the vast army of newly 

 described American hawthorns meet these 

 requirements. It has been said that Nature 

 in her operations knows no species; she 



