234 



NOTES ON A NEW TASMANIAN PLANT. 



How restricted some parasites are in this respect is demon- 

 strated in Tasmania and Victoria by the Cyttaria Gunnii, 

 which never occurs on any other tree than Fagus 

 Cunninghami, all other Cyttarias occurring also only on 

 Beech-trees. 



For Australian phytogeography the finding of a Thismia 

 not as might have been looked for in North-Eastern 

 Australia, but in such an extreme extratropic isolation, is one 

 of the most remarkable additions to our recent knowledge in 

 this direction. But the discovery of this plant is also in 

 other respects of special interest, because it shows that the 

 genera Geomitra and Bagnisia should be united with Thismia, 

 the merging of Geomitra into Bagnisia having already (1883) 

 been advised by Bentham and Hooker, a view acted on by 

 Engler in the " Pflanzen-Eamilien," 21 Lief. p. 48 (1888) 

 Those who prefer smaller genera for systematic arrangements 

 against more natural and more easily employed larger genera 

 with subdivisions, might assign to our new plant even generic 

 rank, then as Eodwaya, but such a separation would mainly 

 rest on the reduction of three of the calyx-lobes to extreme 

 minuteness, and on the coalescence of the tips of the longer 

 calyx-lobes somewhat in the manner of the Southwellias 

 within the otherwise far disallied genus Sterculia ; in typical 

 Thismia the lobes are perfectly disunited, much differing 

 as regards form in various species, while in Bagnisia and 

 Geomitra they are variously united. Adopting all these 

 plants for one generic group, we would obtain chiefly chrono- 

 logically the following arrangement, so far as the species are 

 hitherto known ; but their series will likely in the course 

 of time receive considerable augmentation yet. 



1. Thismia Brunoniana ; Griffith in the transact, of the 



Lmnean Soc. xix., 341-344 t. 39 (1844). Tenasserim. 



2. Thismia Gardneriana ; J. Hooker in Thwaites enuin. plant 



Zeylan. 325 (1864). Ceylon. 



3. Thismia Macahensis ; Bentham and J. Hooker, gen. plant 



iii., 459 (1883) implied. 

 Ophiomeris Macahensis ; Miers in transact. Linn. Soc xx 



374-379, t. 15 (1847). Eio de Janeiro. 

 This and the closely allied O. Ignassuensis (Miers I.e.) 

 have an obliquely bulging calyx, free stamens, bicaudulate- 

 filaments and upwards converging anther-cells, so that the 

 genus Ophiomeris, against the views of B. and H. might 

 perhaps be kept up. 



4. Thismia hyalina ; Bentham and J. Hooker, gen. plant, iii , 



459 (1883) implied. 



Myostoma hyalinum ; Miers in transact., Linn. Soc. ixv 

 474-475 t. 17 (1866). Organ-Mountains. 



