III.— BOTANY 



Art. XXVIII. — A Short Account of the Plant-covering of 



Chatham Island. 



By L. Cockayne. 



r Read before the Philosophical Institute of Canterbury, 6th November, 



1901.] 



Plates XVI.-XIX. 



The group of islands and rocks known collectively as the 

 " Chatham Islands " lies isolated in the South Pacific Ocean, 

 at a distance of about four hundred and fifty miles east- 

 south-east from the nearest point in New Zealand. It lies 

 between the parallels 43° 30' and 44° 30' south latitude, and 

 the meridians 175° 40' and 177° 15' west longitude. The 

 largest member of the group — Chatham Island — is about 

 thirty miles in length, and contains 222,490 acres. Pitt 

 Island is next in size, with a length of barely eight miles 

 and a half, and an area of about 15,000 acres. The only 

 other islands sufficiently large to contain flowering-plants to 

 any extent are Mangere and South-east Island, each of which 

 is about a mile and a half in length. Pitt Island lies to 

 the south of Chatham Island, from which it is separated by 

 a narrow passage of water, about fourteen miles in width, 

 called Pitt Strait. Mangere lies to the west and South-east 

 Island to the south-east of Pitt Island, from which the 

 former is distant a mile and a half and the latter a mile and a 

 •quarter. 



The botanical history of the Chathams dates from the year 

 1840, when Dr. Dieffenbach visited the islands on behalf of the 

 New Zealand Company, and made at the same time a small 

 collection of the plants. These are recorded in the " Flora 

 Nova>Zelandiae," and comprise only some twelve species 

 of phanerogams and vascular cryptogams. For a space of 

 eighteen years after Dr. Dieffenbach's visit nothing more was 

 done botanically, when, a direct trade being established between 

 Melbourne and the islands, a few plants were from time to 

 time brought to Baron F. von Mueller, including the remark- 

 able Myosotidium nobile (45, p. 2) ; but it was not until the 

 year 1863 that the first real botanical exploration of the 



