The Hawthorns 



and opinion on the subject be considered as final. It takes time 

 to test the stabiHty of species. Thousands of seeds have been 

 collected from haws and planted in the nurseries of the Arnold 

 Arboretum. Probably no such undertaking was ever projected 

 and carried out. What is it all about? Take an example. 



A new kind of hawthorn was found growing wild on a hillside 

 within the very gates of the Arboretum. It was evidently related 

 to C. mollis, but was considered sufficiently distinct to deserve 

 rank as a new species. Professor Sargent called it Cratcegus 

 Arnoldiana. A keen-eyed scientist found the same species growing 

 wild along the river banks at Medford, Massachusetts. Does it 

 grow elsewhere? Nobody knovv's, yet. Seeds from both groups 

 are growing in the nursery. They have shov/n their foliage. 

 They will be set out in due time, and ultimately will produce 

 flowers and fruit for comparison with the parent trees. If they 

 are alike and "true to type," the inference is that the species is 

 distinct set off by clear-cut characters from its near relatives. 

 If, on the other hand, these seedling trees closely resemble C. mol- 

 lis, rather than their own parents, the variability is evidence against 

 their deserving a distinct name and a place among species. Their 

 seeds must be planted, and seedling trees brought to bearing. 

 What will their testimony be? How will they compare with their 

 parents and grandparents? 



It takes years of careful study to find out these things. Accu- 

 rate records must be kept ; each tree has its pedigree and biography 

 written in full in the card catalogue, and a prophecy of its value 

 in cultivation. 



Perhaps there are not so many species as are now described. 

 One student of the genus thinks that the virgin forests kept 

 hawthorns suppressed. The clearing of the land gave them a 

 chance. The multitude of forms now seen, he thinks may be 

 seminal variations, due to the more favourable auspices under 

 which the seedling trees now grow. Until recent years, nobody 

 was making observations on the subject. Now, in many regions, 

 this scientific study is being carried on independently or in con- 

 junction with Professor Sargent. The outcome will be a large 

 body of knowledge regarding the genus. 



The horticulturist is beginning to realise the value of the 

 hawthorns. The showy flowers and fruits, the vivid colouring 

 of autumn foliage, and the striking character expressed in winter 



304 



