BOTANICAL REMINISCENCES OF SAN FRANCISCO. 171 



Conchalagua, against the intermittent fevers, dyspepsia, etc. 



Tiiis vegetation disappeared in summer without leaving 

 any trace, and, only where subterranean water courses 

 approached the surface, luxuriant bunches of Bnccharis 

 Dougldsii, En'geron Philadelphicus, Aster Chamissonis 

 and Helcniiim 'puberulum covered the ground, occasionally 

 overspread by the flowering Twin-berry, Lonicerdinvolitcratd 

 with its shining blackberries in their dark red involucres, or 

 Sawhucns glauca and Ribes glidinosum. 



These moist spots became confluent towards the North 

 but towards the South the steep declivity of the ridge 

 separated, in a very decided way, dry sand and inaccessible 

 bog without any intervening transitional formation. 



The bog itself was perceptibly lower at the foot of the liills 

 than towards its center, which was occupied by a character- 

 istic swelling of the turf, which gave origin to a net of inter- 

 woven little water-courses, permeating a kind of meadow and 

 themselves covered by a moss-like carpet of an Azolla. The 

 water seemed remarkably clear, but nevertheless deposited 

 on the stems and lower leaves of grasses and herbs a thick 

 ochraceous crust. 



The vegetation of this locality was exceedingly character- 

 istic. It was a kind of Arctic oasis amidst a vegetation of 

 California type. 



Where the water collected into small rivulets, it became 

 hidden under the dense, mossy, and very deceiving carpet of 

 Azolla. The turf consisted to a great extent of Cyperaceae, 

 especially Scirpus, Carex, and, in one locality, even an 

 Eriophorum. Out of this turf emerged the fragrant 

 Habenaria leucostachys and Menyanthes trifoliata and, in 

 one locality, Epipactis gignntea, with Sisyrinchiiim bellum. 

 These were the most conspicuous and at the same time the 

 most frequent plants of the formation. 



Where the rivulets approached and extended to the serpen- 

 tine courses of the tide water creek, the formation changed; the 

 Azolla carpet dissolved into floating islands before disap- 

 pearing entirely, the grasses and Cyperaceae lost their dens>> 



