66 Kelly, Plant Distribution in the Healesville District, [v^'k xxxi. 



particular district, but more or less to the class of country of 

 which it forms a part. 



Rock Covering. — The railway line has been opened about 

 twenty-seven years, and the cutting has looked much the same 

 during the last ten years, at the least. The hard face of almost 

 vertical rock is patched over with flat lichens, mostly round, 

 from little more than apparent stains to those considerably 

 raised, just as one sees them on a neglected slate roof, and it 

 is understandable why the symbiotic habit of this plant, with 

 its humble allies, is necessary to sustain life in such conditions, 

 on the sharing principle of Jack Sprat and his wife. Here 

 Nature leaves her finger-prints upon the wall that she may be 

 identified. 



Mosses, next in vegetative progression, fill little nooks and 

 crannies and cling to the softer portions of the wall. On the 

 banks where the surface has been removed are large patches 

 of moss, chiefly Polytrichum, and these, drying in midsummer, 

 afford fine colour protection for the grasshopper, Exarna 

 australis. In places where there is a little more soil are many 

 kinds of the herbaceous Xerophytes, such as Erythrea australis, 

 Hypericum japonicum, and the Willow Herb, Epilobium 

 glahelluni, and, in stunted forms, the neighbouring shrubs and 

 trees, Kunzea peduncularis, Leptospermum scopariiim, Pultcncca 

 Gunnii, Daviesia latifolia, D. corymbosa, Goodia lotifolia, 

 Cassinia aculeata, Exocarpus cupressiformis, Casuarina 

 suberosa, and three eucalypts, E. obliqua, E. rubida, and E. 

 amygdalina, with the welcome variation of trails of Harden- 

 bergia monophylla. The Whiptail Fern, Asplenium flabelli- 

 Jolimn, is almost a lithophyte, fastening into rocks which have 

 scarcely any covering but moss or lichen. Having so clung, 

 it hides, however, in a shady crevice or beneath a shelf. This 

 habit is noticeable, too, in the common maiden-hair fern, 

 which, however, can adapt itself to many situations, from 

 barren rocks to the wet loam of a stream bank. Somewhat 

 different are the species that adapt themselves to hard road- 

 sides, as the Knotweed, Polygonum aviculare, white clover, and 

 Lythrum hyssopifolia, defying the traffic to a considerable 

 extent. Those that favour the less-used roadside might be 

 justly classed with the chersophytes (waste land j)lants) found 

 mostly in back yards and rubbish tips, and between the two, 

 and including most of their components, is the more modern 

 sodality, the vegetation of railway lines, the cradle of exotic 

 weeds. 



Of the carpet vegetation of the flats, except such as consists 

 of grasses, the dominant features have been fairly indicated. 

 The lowest hill-covering differs considerably. It is an associa- 

 tion of most of the lithophytes, dwarf forms of many of the 



