124 MISSOURI BOTANICAL GARDEN. 



governs its position and im 



& 



specimens 



each blooms, so that the different species of the collection, 



flowering 



flowering at different times, may represent the lo 

 sible period of bloom. 



Very early bloomers like Forsythia, autumn 

 sorts, like Witch Hazel and all those that flower when 

 there is little else to gladden the eye, are always sought. 

 For landscape effect, the time of leafing and fruiting is of 

 equal importance. The Virginia Creeper, while it is an 

 excellent summer cover, is perhaps most appreciated for a 

 short time in autumn, when it assumes that crimson tinge, 

 quite in keeping with the season, after many of the 

 deciduous sorts have shed their leaves. The fact that 

 some sorts carry their fruit into the winter months adds 

 much to their value and helps to determine their relative 



The ripening rose hips, turning 



positions in a planting. 



from 

 mus < 



red berries, rich foliage and rugged twigs, each have a 

 winter beauty that is best brought out after a careful study 

 of their phenological characteristics. 



growth 



a- 



ture that cannot be definitely arrived at by any mechanical 

 method. While the thermometer may register the actual 

 temperature of the atmosphere or soil at any given time, it 

 does not, by any means, measure the sum total of heat 

 that has been received, during a given period, as does a 

 certain stage in the development of buds or leaves. This 

 fact is taken advantage of by the cultivator. In planting 

 for a succession of vegetables, for example, a difference of 

 four weeks, in sowing the seed, may result in a difference 



maturin 



table. 



may be indicated 



rapidity of growth of trees and shrubs. 



The phenological characteristics of plants also aid in 



