THE FLOWEIU>rG-TTMES OF SOME ERTTTSIT ELMS 41 



1913, March 10 {ahoui). — A single young- tree (height 41 feet) 

 growing in a meadow beside College Wood (a portion of which, cut 

 down within my recollection, formerly included it) had not come into 

 llovver when visited at this date. 



JMarcli 30. — The tree has flowered since the 10th inst., and young 

 samaras are just beginning to form. 



April 6. — The samaras are now largely developed, giving a 

 decidedly green tinge to the tree, though no foliage has yet appeared. 



1914, March 22. — Tree in flower very fully. 

 April 29. — Tree bearing samaras in abundance. 



1915, April 5. — Tree in flower very fully. 

 1916. — Date of flowering not noted. 



I made also a few observations on ten or a dozen trees of the 

 same species, growing near Chobbins Farm, a few hundred yards 

 distant : — 



1917, March 24. — Flowers not yet open or very few, if any. 

 (This is unusually late for this species.) 



1919, March 2. — Trees just beginning to flower. 



The foregoing observations show that in Essex TTlmus montana 

 flowers, with fair regularity, about the middle or the end of March, 

 though sometimes not until the beginning of April, as in 1915 and 

 1917 : that is to say, its flowering-time averages from four to six 

 weeks later than that of Z7. nitens. 



In most years, therefore, there is little probability of these two 

 species hybridizing, even when they grow in close proximity to one 

 another, as they did round my house. Yet in years in which U. nitens 

 happens to flower exceptionally late (as it does sometimes), the 

 flowering-times of the two become synclu'onous. This was the case, 

 for instance, in 1917, when the trees of both species which grew 

 round my house flowered together during the last week of March. 

 In such years hybrids may easily be produced. Few botanists realize, 

 I fancy, how profuse is the amount of pollen produced by our Elms. 

 I have several times brought into the house twigs of both the species 

 noticed above and bearing flowers with anthers just about to dehisce, 

 and I have been surprised the following morning by the amount of 

 pollen the anthers, assisted by the warmth of the room, had shed 

 on my writing-desk. This abundance of pollen, carried by the wind, 

 would, of course, facilitate hybridization, probably even between 

 trees growing a mile or more apart. 



In addition to the foregoing, I made one observation on a single 

 tree (pronounced by Prof. Henry to be probably Z7. major Sm.) 

 growing in a roadside hedge at Stisted in North Essex. It had a 

 much rounder head than any typical example of U. nitens, and the 

 ends of the lower branches were remarkably long and pendant. It 

 may have been a hybrid with some ornamental tree in an adjacent 

 garden. 



1911, February 12. — Tree in full flower. 



May IG. — It was reported to me that this tree had produced no 

 fruit. 



