260 MR. $. MOORE ON THE FLORA 
The exclusively gnamma-rock plants observed by me are the 
following :— 
Keraudrenia integrifolia, Stackhousia spp., Cryptandra petrea, 
Owylobium graniticum, Mirbelia microphylloides, Drosera spp., 
Kunzea sericea, Podolepis pallida, Helichrysum semipapposum» 
Helipterum Manglesii, Goodenia hederacea, Dampiera lavandu- 
lacea, Isotoma petrea, Solanum lasiophyllum, Eremophila gra- 
nitica, Prostanthera Baxteri, Grevillea nematophylla, Hakea 
suberea, Parietaria debilis, Thelymitra longifolia and T. anten- 
nifera, Pterostylis pyramidalis, Borya nitida, Juncus bufonius, 
Centrolepis mutica, Scirpus cartilagineus and X. cernuus, Notho- 
lena distans, Gymnogramme Pozoi. 
The presence at the rocks of many of the herbs in this list, 
especially the Droseras, the Orchids, Parietaria debilis, the 
Cyperacex, and the Ferns, is undoubtedly due in part to the fact 
that the places where they have managed to establish themselves 
are specially favoured by their position, and are enabled to retain 
moisture longer than other spots ; in the case of ferns, too, shade 
as well as moisture is essential. One finds such plants, there- 
fore, only in crannies between the rocks, or on level spaces 
abutting upon a sloping rock-face down which the water pours 
during a storm. But this explanation will not suffice for Hakea 
suberea which is a tree, nor for such large shrubs with long roots 
as the Aeraudrenia, the Oxylobium, Kunzea sericea, Eremophila 
granitica, and Grevillea nematophylla. Why, too, should we find 
such lowly herbs as Podolepis pallida and Helichrysum semipap- 
posum near gnamma-rocks, it may be weeks after rain has fallen 
and all surface-water has drained away, while on red soil not 
more dry, their place is taken by IZelipterum Fitzgibboni and 
rubellum, Schenia Cassiniana and Cephalipterum Drummondii? 
l know of low-lying spots between Coolgardie and Gibraltar 
where rain-water lies for some time, and where in the spring 
there is a perfect carpet of flowering herbs, yet not one of them 
is identical with a gnamma-rock species. Professor Tate? met 
with a somewhat similar rock-flora in Central Australia; but I 
cannot agree with him in thinking these plants to be representa- 
tives of an ancient flora driven, by gradually increasing drought, 
to take refuge among the rocks for the sake of the supposed 
larger amount of surface water to be found there, though in a 
* ‘Botany of the Horn Expedition,’ p. 120, 
