10 



tuberous plants, together with ephemerals, are all character- 

 istic of this formation. As yet the associations within this 

 formation have to be denned. Forest is represented in 

 the Adelaide district by stringybark (Eucalyptus obliqua and 

 capitellata), while scrub is typical of the quartzite hill slopes. 



The characteristic scrub association of the sclerophyllous 

 woodland has Eucalyptus leucoxylon as the dominant tree, 

 but the bulk of the vegetation consists of very many species of 

 shrubs averaging 1-1*5 m. high, and sometimes forming a close 

 thicket. But little shade is cast, however, owing to the small 

 size of the leaves. Such an association has been compared 

 with the maqui of the Mediterranean, or the chaparral of 

 California by Warming (13: p. 308). Bulbous and tuberous 

 plants are common in this association in South Australia, as 

 in those of the Mediterranean and Cape Colony. In the 

 alluvial area considered they are, however, unusually abund- 

 ant. It is, moreover atypical in the abundance of the sedge 

 (Schoenus apogon) and in the change between the relative 

 proportions of shrubs on the one hand and geophytes and 

 ephemerals on the other. In this respect it agrees with the 

 alluvial swamp described by Diels floe. cit.J. Provided it be 

 understood that the presence of standing water, or indeed any 

 considerable soil moisture, is merely seasonal, and that there 

 is a prolonged period in which the ground is baked hard, 

 the area may be regarded as a swamp. True fresh-water 

 swamps, the soil of which is wet most of the year, are not 

 common in the hilly regions of South Australia, and they 

 present a very different flora. 



It is as members of the geophytic element in this seasonal 

 swamp on alluvial sands that Isoetes and Phylloglossum 

 occur. Isoetes appears to have a wider range, but in all 

 other stations known at present it is a geophyte on alluvial 

 sandy soil, only isolated plants being actually submerged 

 during the growing season. Isoetes (fig. 3) agrees with many 

 of its cogeners in general size and approximate depth to which 

 the stock is buried. Phylloglossum is a much smaller plant 

 than the other geophytes, for which reason Diels perhaps was 

 led to class it with the ephemerals. It is, however, not 

 ephemeral, but typically geophilous in its growth. Its 

 annual tuber, sunken by a stalk to a constant average depth, 

 is functionally comparable with the many other tubers, etc., 

 developed by its geophytic neighbours, from which Phyllo- 

 glossum differs so markedly in size. 



Summary. 

 1. Isoetes Drummondii and Phylloglossum Drummondii 

 are recorded for the first time from South Australia, thus 



