252 



The Plant World. 



are the most abundant forms. Torreya or Tumion, or California 

 Nutmeg, is not a common tree, but there are many specimens of 

 it, some of a height of fifty feet or more, on the mountain sides 

 or in the narrow valleys in the mountains. 



About five miles westward is the great fault, the Portola or 

 Andreas Fault, along which repeated movements have taken 

 place resulting in earthquakes. In many places along this fault- 

 line there are ponds, some very small, others large enough to be 

 used as a part of the water supply of San Francisco. The vege- 

 tation of some of these ponds and their immediate surroundings 

 is extremely rich, and forms occur there not known elsewhere 

 in the region. The water in the higher of the ponds is less hard 

 than elsewhere on the peninsula. This may account in part for 

 the unusual abundance of Desmids and other strictly fresh- 

 water forms. 



! The streams from the mountains into the Bay are peculiar 

 in that their beds, in the lower part of their course, are raised 

 above the valley-floor. Along the shaded banks of these streams 

 and in the streams themselves, plants of all sizes from trees to 

 algae may be found which otherwise are very limited in their dis- 

 tribution. Thus, within a half mile of the botanical laboratory 

 I have found in the San Francisquito Creek, or on its banks, a 

 Batrachospermum, liverworts, and trees which do not other- 

 wise occur in the valley but are abundant in the coast ranges. 



I might go into details regarding the plants living in the 

 extremely diversified country lying within a radius of twenty 

 miles of Stanford University, but such detail would be more 

 valuable if given by systematists. The specialists on algae, 

 fungi and lichens, archegoniates, herbaceous plants, and trees, 

 have here abundant material under their hands, and no one's 

 energy is sapped by excessive heat or cold 



