46 A CONTRIBUTION TO, ETC. 



surrounding influences of soil, light, and moisture, we may be led 

 to conclude that the same plant assumes a different appearance 

 when growing amongst the hard rocks, in the sheltered cave, or 

 on the alluvial bank of some creek. G. tnicropliylla when attain- 

 ing the height of two feet or more, and spreading its divided 

 fronds in wild profusion in spots favoured by nature with a rich 

 soil and abundant moisture, is one of our most elegant and grace- 

 ful ferns. It loses much of its beauty when dry, but it may be 

 kept verdant for a long time in a vase, if water be applied to it 

 occasionally ; or when tied in bundles and suspended from the 

 ceiling, it may be usefully employed .as a resting place for flies > 

 The extreme variableness of this species has been noticed when 

 under cultivation in Europe, and Berkeley remarks, " I have seen 

 at Kew, the minute pinnules of a Gleichenia expanded to three 

 times their normal length and breadth, and the margin at the 

 same time unfolded, when placed in a hot damp atmosphere." 

 (Int. to Crypt. Bot., p. 516.) G. flabellata is an ornamental 

 species, differing from the preceding in having the segments of 

 the fronds linear, and the sori near the middle or the forking of 

 the veinlets : it is also a larger plant, the fronds being divided 

 two or three times, and assuming a somewhat arborescent or 

 palm-like appearance. G. Hermcumi (Brown) or G. dichotoma 

 is chiefly a tropical species, still more divided than the last, the 

 ultimate branches bearing simply forked pinmr, and the segments 

 never decurrent. The last .two species are separated from 

 Gleichenia by some authors, and placed in the genus Mcrtemia (so 

 named in honor of the French botanist, E. C. Mertens), but 

 Hooker retains Brown's arrangement, and refers these species 

 to the sub-genera of Gleichenia. This genus was so called in 

 commemoration of Baron P. E. Von G leichen, a German botanist, 

 and the species to which I have referred have long been under 

 cultivation in England, not only at Kew, but in private nurseries. 

 In the very valuable list of Australian ferns, lately published 

 by Dr. E. Mueller, in the 37th number of his Fraymenta Phyto- 

 (jraphiw Australia, vol. 5, that learned writer extends our Glei- 

 clienioe to six species, uniting G. microphylla, G. speluncce, G. 

 rupestris, G. semivestita, and G. liecistoplujlla, under the name of 

 G. circinata. In the neighbourhood of Lane Cove, I have found 

 several forms of G. wicropJii/Ua, and G. Jlabellata, which lead me 



