214 86. GRAIVUNA. 



again stopped and repeated the process; having succes- 

 sively set do^-n the names of the following plants in the 

 order of first seeing them between the two points of rest, 

 Triodia decumbens, Pedicularis sylvatica, Pedicularis pa- 

 Instris, Cynosurus cristatus, Carex binervis, Carex pi- 

 lulifera, Linum catharticum, Carduus palustris, Pteris 

 aquilina. On afterwards calculating the altitude of the 

 two stations (Luzula spicata and Pteris aquilina) I found 

 them to be 1800 and 1400 feet. And as the name of 

 Cynosurus cristatus was entered in my note-book in the 

 middle of the short list of plants noted between those two 

 altitudes, I assumed the height of the grass to be about 

 1600 feet; it might be rather more or rather less, and is 

 called 500 yards (1500 feet) in the formula, in order to be 

 on the safer side, below rather than above the extreme 

 height for an ascending species. But if the Luzula 

 spicata had been again seen with the Cynosurus, I should 

 have reckoned the height of the rush at 550 yards (1650 

 feet), and not 500 yards; because that was a descending 

 species, and any chance of mis-estimate should be kept 

 within the actual range. It will be borne in mind here 

 that no narrower steps of altitude than 50 yards are used 

 in this work. 



1338. Cynostjrxjs echinatus, Linn. 



Area (1 2 3) ,^ * * * [8 9 10 11 ***** * 18], 

 Alien in Britain. Native Sarnian. Occasionally intro- 

 duced into Britain with agiicultui'al seeds, or in ballast ; 

 but usually soon disappearing again from any spot in 

 which it may be found ; so that it can scarcely be ad- 

 mitted among British plants in any sense of the term, 

 even extended so as to include the semi-naturalized 



