508 Osborn. — Some Observations on the Tuber of Phylloglossum . 
In South Australia the geophytic element in the flora of certain areas 
is very large. 1 Physiologically the tuber of Phylloglossum is comparable 
with the tubers, corms, &c., of the spermophytes among which it grows. 
Like them, it has an average depth to which the perennating organ is 
sunken, a depth that it maintains in spite of accidental circumstances that 
tend to bury or expose the tuber. In this respect its behaviour agrees with 
that of the geophytes of other countries. 2 
The analogy drawn by Wernham 3 between the tuber of Phylloglossum 
and the stalked droppers of Tulipa and Erythronium described by 
Mrs. Arber 4 seems particularly apt, though other workers have found 
nothing to justify his conclusions as to the morphological nature of the 
tuber. 
It may naturally be asked how far the development of adventitious 
tubers upon leaves is a normal occurrence and so of value for purposes of 
vegetative reproduction. Unfortunately no definite answer could be given 
to such a question. In 1917 seven leaves in various stages of tuber forma- 
tion were collected in the field. Had these been left undisturbed, possibly 
not more than two of them, those shown in Text-figs. 8 and 12, would 
have developed sufficiently to be of value for vegetative propagation before 
the oncoming dry season put a stop to all growth. On the other hand, in 
certain seasons the district near to Adelaide in which Phylloglossum grows 
may remain green and growth be possible until the end of December. In 
Rainfall in Inches at Belair, South Australia. 
Altitude 1,009 ft. 
Year. 
Jan. 
Feb. 
Mar. 
A pi. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Total. 
1915 
0-62 
0.03 
0.46 
2.58 
4.20 
6.92 
3.88 
4.67 
5.09 
0.94 
0.36 
0.07 
29.82 
1916 
0.65 
0.12 
0-40 
2.18 
1*20 
11.08 
3-55 
5-69 
1.96 
2.41 
4*08 
1.26 
34-58 
1917 
0.50 
2.77 
3-27 
i-39 
6-92 
4*53 
5*9i 
4.41 
5-54 
3.10 
1.23 
1.29 
40.86 
1918 
Average ' 
0.63 
0.68 
0.46 
1.58 
3.86 
4.88 
3*3 2 
4 ,]r 4 
i*35 
4*39 
o-45 
c*6o 
26-34 
Rainfall 
for 38 
years 
0.99 
0.65 
i-39 
2-59 
3-39 
4*95 
3*55 
3-5 2 
2-81 
2.24 
i-43 
1*12 
28-63 
such circumstances there is a reasonable chance that most leaves which 
began to form tubers would mature them. In this connexion it is interest- 
ing to recall that in some spots a considerable percentage of single-leaved 
plants was observed at the close of the 1917 growing season. 5 Many of 
these plants were very minute, yet all were from tubers of a preceding 
season. The year before, 191b, was unusually wet during November. 6 It 
1 Osborn, T. G. B. : loc. cit., p. 9. 2 Goebel, K. (1905): p. 466. 
3 Wernham, H. F. : loc. cit., p. 343. « 4 Robertson, A. (1906): Ann. Bot., xx, p. 429. 
5 Osborn, T. G. B. : loc. cit., p. 4. Of 184 plants 39 had one leaf only. 
6 I am indebted to Mr. E. Bromley, State Meteorologist, Commonwealth Meteorological 
Bureau, who has kindly furnished the rainfall records at Belair which are given above. 
