L 
xxiv INTRODUCTION 
The question of what should be included in the Introduction 
was never discussed. I only know that it was Sir Henry’s inten- 
tion to compile a Glossary, and I undertook to prepare a Synopsis 
of the Natural Orders. I am wholly responsible for this part of 
the book, except that I am indebted to my friends Mr. C. W. 
Hope, late of the Engineering Department, Government of India, 
for a list of the Ferns, and Mr. J. S. Gamble, C.I.E., F.E.S., 
formerly Conservator of Forests to the Government of India, and 
Director of the School of Forestry at Dehra Dun, for some notes 
on the Vegetation. He and Sir Henry were old friends, and they 
botanised together the district of Simla. 
POSITION, AREA AND CLIMATE 
The area is defined or rather described in the Preface, and the 
Map supplies further information. 
The town of Simla, the centre of the district whose Flora is 
described in the following pages, is situated in about 31° 6' N. 
latitude, and 77° 10' E. longitude, at an altitude of 7,230 ft., and 
exactly on the watershed of the two great river- systems, the 
Ganges and the Indus. The rivulets flowing northward and 
westward are feeders of the Sutlej, which rises in Western Tibet 
and forms the most easterly of the five principal tributaries of the 
Indus, which flows into the Arabian Sea ; whilst the Giri river and 
its affluents to the east flow into the Jumna, one of the great 
tributaries of the Ganges, which debouches into the Bay of 
Bengal. 
The climate of the district exhibits considerable variations at 
different elevations and exposures. In round numbers there is a 
total difference of 8,000 ft. in elevation ; and then there is the 
factor of aspect, whether northern or southern, to be taken into 
account. From observations near Simla at about 7,000 ft. the 
mean temperature of January, the coldest month, is 40°*6 Fahr., 
and of June, the warmest month, 67°'l ; whilst for the year it is 
54°*86. The lowest temperature recorded, 26 0, 6, occurred on two 
days in February 1882, and the highest, 86°, on three days in May 
Abies Smithiana. Full synonymy, however, is given in the Flora of British 
India, to which the inquirer is referred. 
One more explanation I may give here. It has been represented to me 
that amateurs generally are puzzled by the ‘ authors,’ that is, the names or 
abbreviations of names, cited after the names of the plants. Briefly the ‘ author ’ 
is the person who described the plant under the genus in question, or referred it 
to that genus, even without description, the plant having been already adequately 
described though, inferentially, referred to the wrong genus. 
