63 



A NEW MICROTIS. 



By R. S. Rogers, M.A., M.D. 



[Read November 6, 1906.] 



Plate XX., Fig. 1. 



Altiiough the genus Microtis is widely distributed 

 tlirougiiout Australia, it is represented by only a few species. 

 In this and the eastern States three have been recorded, viz., 

 M. j)orri folia, M. parviflora, and M. atrata. Of these, the 

 second has been regarded by Baron von Mueller and others 

 merely as a variety of the first. M. porrifolia is found in 

 all the States and in New Zealand. 



M. 'parviflora is a rarer form, but occurs in all the eastern 

 States, though not in South Australia. 



Both these species were discovered by Robert Brown in 

 1802. 



M. atrata is a minute species, rather sparsely distributed 

 in this State and in Victoria. It was named by Lindley in 

 1839. 



The discovery of a totally new species in this State is 

 therefore of more than usual interest. I found this plant 

 on November 2, growing in a swamp at Myponga, a place 

 situated about thirty-seven miles south of Adelaide. It was 

 not rare in this locality, and I was able to collect a large 

 number of specimens w^ithout difficulty. 



Because of its round tongue, I have named it "Microtis 

 orhicvlaris." 



Microtis orbicularis, nov. sp. 



The plant varies from about 7 to 12 inches in height. 



Its stem is rather slender, with a marked and character- 

 istic angulation, or shoulder, where it emerges from the sheath. 

 This divergence from the vertical often makes an angle of 45 

 degrees, and is present in over a hundred specimens which I 

 have preserved. There seems to be a marked uniformity, too, 

 in the distance between the fistula in the leaf and the beginning 

 of the inflorescence. This is about half-an-inch. 



The leaf rarely reaches more than halfway up the spike 



The spike varies in my specimens from J in. to 3J in. It 

 presents a generally flatter appearance than in ''M. porri folia,'' 

 and the flowers are not so crowded as in that species, varying 

 from 5 in the shortest specimens to 30 in the longest. 



The flowers are minute, sessile, and subtended by a wide, 

 obtuse, clasping bract, which covers in the greater portion of 



