320 BROOKLYN BOTANIC GARDEN MEMOIRS 



able. But here again this is dupHcated by Heracleum and other 

 Umbellifers, as well as by many Araliads. 



The writer can never forget his first knowledge obtained for the 

 almost exactly synchronous floral expansion in Oenothera grandiflora. 

 Two enthusiastic botanical lady friends had cultivated many of these 

 handsome plants along with numerous other species nearly twenty- 

 three years ago. He was asked to pay a visit about 7 P.M. on a mid- 

 July evening. Chairs were set out amongst a group of the Oenotheras 

 and he was asked to watch and listen. From 7.15 to 7.50 a constant 

 succession of "pfuft's" was heard, that indicated the bursting of the 

 sepals and unfolding of the petals, which rapidly took place before 

 one's eye. From the condition where scarcely a flower was open to 

 begin with, to that seen at 7.50 the change was striking, for now the 

 plants were gay with large expanded blossoms. Six years afterward 

 the writer was carried by train from Botzen to Meran in the Tirol 

 toward 7 P.M. and running for miles by the banks of the Adige River 

 he witnessed the same synchronous series of events for plants of 

 Oenothera that had been introduced there. 



In connection with genetical studies increasing attention has been 

 paid during the past fifteen years to the behavior of varieties and 

 hybrids. But extremely little has been published as to the relative 

 period of flowering, fruiting or like phenological conditions for each 

 parent and for the hybrid. But a very wide field for exact observa- 

 tion is here awaiting study. The writer has drawn attention to some 

 results and has since accumulated others. Thus, the relative pro- 

 duction or not in the wild state of hybrid Sarracenias is almost wholly 

 determined by the synchronous or asynchronous relation of the 

 flowers. So the scarcity of wild hybrids of S. rubra with other species 

 is in part due to difference in locality, but in large measure to later 

 blooming period of that species. Under cultivation by placing plants 

 in greenhouses of different temperatures a synchronous blooming can 

 be effected, and such striking hybrids as vS. Popei and S. Chelsonii 

 represent the progeny. In such cases then an exact expenditure or 

 retardation of definite heat units effects a synchrony that in their 

 natural environment does not exist. The practical application of such 

 methods in the prosecution of hybridization experiments will ensure 

 success where failure might otherwise result. 



The writer has watched with interest the phenological behavior of a 

 wild hybrid between Myrica cerijera and M. carolinensis, that his 

 former graduate student. Dr. Youngken, has described under the 

 name of M. Macfarlanei. The first of these is a narrow-leaved ever- 

 green shrub or low tree, that has its northern limit in New Jersey 

 round the mouth of the Great Egg Harbor River, and there the rather 



