72 J. B. CLELAND. 



NOTE on the GROWTH of the FLOWERING STEM 



OF Xantliorrhcea hastilis, R.Br. 



By J. Burton Cleland, m.d., cii.m. 



[Read before the Royal Society of N. S. Wales, June 4, 1913.'] 



In April, 1912, one of several specimens of grass-tree 

 (Xantliorrhcea hastilis, R. Br.), which had been rescued 

 from destruction when the ground, which is now my garden, 

 was cleared for building, started sending up its flowering- 

 stalk. This stem eventually reached a height of about 

 eight feet with a diameter of about an inch. My attention 

 was soon attracted by two features, the rapidity of growth 

 and the inhibitory influence of direct sunlight. The former 

 soon led me to take measurements with a foot rule, and 

 the latter induced me to note the height both morning and 

 evening. Appended are the daily measurements taken. 

 The most rapid rate of growth, it will be noted, was 

 between 6 p.m. on April 15 and 8 a.m. next morning, dur- 

 ing which the height had increased by 4 inches. The 

 preceding hours of daylight had only added f in. and the 

 (Succeeding ones | in. The next night saw a further addition 

 of 3 in., and the following day \\ in. The night of April 

 18 — 19 saw 3J ins., the preceding day having added \ in. 

 only, and the succeeding one nothing. These are the most 

 striking instances of rapid growth by night and slight 

 growth by day, but throughout, if the weather were bright 

 and sunny, the same tendency was manifest. On April 27, 

 the influence of direct sunlight was strikingly displayed. 

 At 8 a.m. the stem was straight, height 4 feet 10 inches. 

 On my return at 1 p.m., I was dismayed to see, as I thought, 

 the stem dying away. It was bent over towards the sun, 

 so that its upper half formed almost a complete semicircle. 



