THE FLORA OF S. E. QUEENSLAND. 271 



Mr. Marks, B.A., in his report on " The Coal Measures of South- 

 east Moreton," p. 51, says, "The basalt — or rather andesite — 

 seems to be the result of at least two flows, the later of which has 

 developed in many places a well marked columnar structure. The 

 earher flow, as seen in the head of Sandy Creek, has more of a 

 laminar structure, and is more readily decomposed." These two 

 basalts overlap on the eastern side of each mountain, but towards 

 the west, especially on Tambourine, the older basalt projects from 

 under the recent flow, and forms the so-called " Cedar Shelf." which 

 on the N. mountain is 5-6 miles long, and supplied to the saw-miller 

 an immense quantity of cedar (Cedrela toona Roxb.), timber now 

 mainly exhausted. 



3. Favourable Conditions. — The decomposition of the basalt 

 produces a very rich soil, in most places of a considerable depth, 

 the distance from the sea is usually less than 30 miles, and the 

 prevailing winds are from the S.E. for the greater portion of the 

 year. This combination of rich soil and a plentiful rainfall produces 

 a most prolific vegetation. As the basalt cap protects the sedi- 

 mentary or metamorphic rocks below from the disintegration of 

 their upper surface, the drainage channels are sharply but not 

 deeply cut in the volcanic rock. Below the basalt the sandstones 

 and conglomerates are weathered into inaccessible precipices, and 

 over them the small streams from the tablelands fall in beautiful 

 cataracts. Near these the basalt is sometimes cut back by water 

 action sufficiently deeply to show the upper layers of the Trias- Jura 

 rocks, here much altered by the action of heat. 



4. Peculiarities of Mountain Floras. — The flora of each of 

 these tablelands has its peculiarities. On Springbrook Ritbus 

 Moorei F. v. M. is plentiful, and reminds one in its wait-a-bit nature 

 of Rubiis aiistralis, the bush lawyer of New Zealand. This rosaceous 

 plant is not found on Beech or Tambouiine mountains. Again, on 

 Springbrook the commonest fern in the vine scrubs is Gleichenia 

 flagellaris, Spreng., which is very rarely seen on the other tablelands. 

 Beech Mountain has generally a growth of Goodia lotifolia, Salis., 

 at the junction of scrub and forest, and the vine scrubs abound 

 with species of Solanum, of which 5. sporadotrichimi, F.v.M., S. 

 aviculare, Forst., 5. simile, F. v.M., are among the most common. 

 Tambourine Mountain has usually a fringe of the moujitain bracken 

 surrounding its scrubs, and marking the junction of scrub and forest. 

 This is the fern Davallia diibia, R. Br., which so closely, in outward 

 appearance, resembles Hypolepis tennifolia, Bernh. On this 

 mountain, too, the open forest is marked by thickets of Indigo fer a 

 aiistralis, Willd, v. minor, one of the most shrubby of the numerous 

 varieties of this variable leguminous plant. 



5. Plant Formations. — The plant associations on these moun- 

 tains are four in number : — 



1. The plants of the jungles, known locally as vine scrubs. 



2. The plants of the open forest country. 



