124 MISSOUEI BOTANICAL GARDEN. 



largely governs its position and importance in planting. 

 In selecting specimens it is desirable to know the date that 

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

 flowering at different times, may represent the longest pos- 

 sible period of bloom. 



Very early bloomers like Forsjiihia, autumn flowering 

 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 

 positions in a planting. The ripening rose hips, turning 

 from green to golden, red and brown, the fruits of Euony- 

 mus or Burning Bush, the Christmas Holly, with its bright 

 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. 



The different stages of the season's growth of trees and 

 shrubs indicate to the meteorologist conditions of tempera- 

 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 

 of only one or two weeks in maturing the plants for the 

 table. The time to plant, then, may be indicated by the 

 rapidity of growth of trees and shrubs. 



The phenological characteristics of plants also aid in 



