HORTICULTURE AND LANDSCAPE GARDENING. 119 



Sumacs: Smoke-tree, Rhus Cotinus. 

 Common, R. typliina. 

 Ds^rarf, R. copallina. 

 Tamarisk: TamaiHx Gallica. 

 Thorns: English, Cratcegus Oxyacantha. 

 Cock-spur, C. Crus-galli. 

 Eed, C. coccinea. 

 Punctate, C. punctata. 

 Douglas', G. Douglasii. 

 Viburnums: Snow-ball, Viburnum Opulus. 



Arrow-wood, V. dentatam and F. puhescens. 

 Dockmackie, V. acerifolium. 

 Sheep-berry, V. Lentago. 

 Virginia Creeper and Japanese Ivy: Ampelopsis quinquefolia. 



Ivy, A. tricuspidata. 

 Walnut: Juglans nigra. 



White-wood: Tulip-tree, Liriodendron Tulipifera. 

 Willows: Wisconsin weeping, Salix Bahylonica? 

 Black, 8. nigra. 

 White, 8. alba. 

 Shining, 8. lucida. 

 Petioled, 8. petiolaris. 

 Pussey, 8. discolor. 

 Beaked, 8, rostrata 

 Winter-bery: Ilex verticillata. 

 Wistaria: Wistaria 8ine7isis. 

 Witch Hazel : HamameUs Virginica. 

 Yellow-wood: Cladrastis tincloria. 



VI. Calendae of Teebs and Sheubs. — A knowledge of the times of 

 the appearing and fall of the leaves of plants is important in many respects, 

 especially when the observation extends over a period of years. lb is neces- 

 sary to a correct knowledge of the vital processes in plants. It is also inval- 

 uable in determining the varying periods of growth in different latitudes 

 and under varying conditions. It also enables us to form an accurate judg- 

 ment of the comparative progress of the seasons in different years. For 

 two and a half years we have kept an accurate record of the appeariug and 

 the fall of leaves in various trees and shrubs upon the College grounds. These 

 records are now presented in a tabulated form. 



In almost every case a single average tree or shrub has been selected for 

 observation during the three years. While this method gives us the charac- 

 teristics of the individual rather than of the species, it is, nevertheless, 

 invaluable from the fact that it eliminates all variations due to soil and 

 exposure; and the writer is confident, from a considerable observation, that 

 even these selected and isolated specimens represent very closely the char- 

 acteristics of the species. 



It is of course impossible to fix an exact date upon which the leaves of any 

 plant begin to fall. An occasional leaf may fall at any time. In the fol- 

 lowing table the date of the first falling of the leaves designates the day 

 when the first conspicuous fall, due to the maturity of the leaf, took place. 

 In the instance of the oaks, which usually hold a portion of their leaves 



