184 



Now, in a tree, the transpiring surface (the leaves) is at a greater distance 

 from the water supply in the soil than it is in the shrub or herb ; besides this, 

 the strata of air surrounding that transpiring surface have properties different 

 to a certain extent from those nearer the soil ; finally, at least in many cases, 

 the transpiring surface of the tree is larger when compared with the corres- 

 ponding surface of the ground than it is in the shrug or herb. 



What is essential to the existence of trees is the continuous presence of a 

 supply of water within reach of the extremities of the roots, and therefore at 

 a considerable depth in the soil. It is immaterial during what season this 

 supply is renewed. In our treeless plains it is (usually) the case that the 

 supply of water several feet below the surface is wanting, or at all events is 

 too intermittent to permit the continued existence of tree-life. The winds are 

 also an important factor, inasmuch as they agitate the air and greatly increase 

 the transpiration of the leaves. The water transpired can only be drawn up 

 from below, arid finally a balance is reached between the efforts of the wind to 

 dissipate the moisture of the leaves and those of the tree roots to keep up the" 

 supply. Thus the winds may result in the death of trees and of the tendency 

 -of the country to form plains or savannahs or steppes. 



The Belah prefers fairly good, slightly undulating, or rather flat land, 

 liable to inundations. 



Generally found in gilgai country. Plentiful in this district. (District 

 Forester Marriott, Dubbo.) Acacia Creek, Macpherson Range. (Forest 

 Guard W. Dunn.) 



Following are some localities for Belah, represented in the National 

 Herbarium, Sydney: 



NEW SOUTH WALES. 



Denilinquin (District Forester O. Wilshire) ; Balranald; Gunbar, 50 miles 

 from Hay, " Belah or Scrub Oak " ; none within 20 or 30 miles from Hay 

 {D. A. Wilson, Acting Forester) ; common near Moama (District Forester 

 O. Wilshire) ; Wagga Wagga ; Cootamundra ; West of Grenfell (District 

 Forester Osborn, J.H.M.) ; Cowra; Forbes district (J. B. Donkin, R. H. 

 Cambage) ; Condobolin (J.H.M.) ; on rich, dark, loamy soil, in the immedi- 

 ate neighbourhood of Myall and Salt-bush plains (R. Kidston, Condobolin) ; 

 "" between the Upper Bogan and Lachlan " (Mr. L. Morton) ; Dandaloo, 

 Bogan River (R. H. Cambage). This is near the place where Richard 

 Cunningham, the Botanist and Superintendent of the Botanic Gardens, 

 lost his life in 1835. The Belah is 



" The gloomy Casuarina trees that witnessed the bloody deed " 



of Richard Cunningham's murder (Mitchell, Trop. Aust., 24) ; Coolabah 

 and the Bogan generally (J.H.M.) ; East Nymagee (R. H. Cambage) ; 

 Bourke (J.H.M.) ; also on the Hungerford-road (see photo.) ; Nyngan 

 (J.H.M.); Dubbo (District Forester Marriott); Coonamble; Curlewis; 

 Moree (W. S. Campbell) ; Narrabri (J.H.M.) ; Porcupine Ridge, Gunnedah 

 (W. W. Froggatt) ; Warrah, on sandy ridges (Jesse Gregson). 

 Found also in Victoria and South Australia. 



EXPLANATION OF PLATE 51. 



A. Type specimen (fruit). 1, Young cone; 2, Ripe cone; 3, Winged 



nut, containing seed. " Between the Bogan and Lachlan Rivers." 



B. Type specimens (staminiferous flowers). Between the Upper 



Bogan and Lachlan." 

 c. Part of a branch showing portions of two .ioints. 



D. Whorled bracts representing leaves, opened out. 



E. A single staminiferous flower, consisting of a single stamen between 



two floral bracts. 



F. Winged nut, containing seed, much enlarged. 



G. Ripe cone. 



