62 ERYTHEA. 



oases of verdure and to reflect^ how nature tries to cover over the 

 defacements of man and once again make all beautiful. 



In December, grasses and erodiums are quite evident; through 

 January and February the appearance suggests a pasture whereon 

 a few cows or sheep might obtain a fair living ; while through 

 March, April, and May the height of the season prevails and the 

 greatest number of species are in bloom. From then to December 

 again the dry brown aspect of summer prevails, though a flowering 

 plant may occasionally be found. To ride in the cable- cars in the 

 winter months, within a short distance of the most crowded part of 

 the city, up steep hills, where the vegetation almost conceals the 

 iron rails of the car-track, is an experience.that amazes the stranger 

 and causes him to marvel at the wonderful effects of soil and 

 climate. 



Nob Hill is the best known of all the hills of San Francisco. At 

 its base, to the east, lies Chinatown, where more inhabitants are to 

 be found to the square-rod than in any other part of the city. On 

 its summit rise the almost uninhabited palaces of the most wealthy. 



During the winter of 1896 my morning walk led me over Nob 

 Hill. I became interested in the plants, that were appearing every 

 day, and began to collect with a view of finding out. how many 

 species could get a living in such apparently unfavorable surround- 

 ings, as well as what kinds of plants they were, where they had 

 come from and what seemed to be their prospects. Mason, Taylor, 

 and Jones Streets from California to Bush-Streets; Jackson, Wash- 

 ington and Clay- Streets from Jones to Powell Streets, were my 

 collecting grounds. The greatest number of species came from 

 Washington- Street, though Jones-Street presented the most luxuri- 

 ant appearance. This is probably clue to the steep incline of Jones 

 Street and its sunny southern exposure. Very rarely is a team 

 driven up these streets, so that there is little danger of the plants 

 being tramped down. 



As the streets of Nob-Hill were not paved so very long ago, and 

 there were no plants left, no seeds even, when the cobble-stones 

 were laid, this recent flora suggests the most adventurous and most 

 hardy plant-pioneers. Some seeds have undoubtedly been washed 

 down from the Reservoir Hill, where alfalfa, clover,, and grasses 

 have been planted; some have come from the kill that rises cliff-like 



