108 MISSOURI BOTANICAL GARDEN BULLETIN 
WEIGHT 
COMMON NAME SCIENTIFIC NAME LBS, PER CU. FT. 
Baise oe: .«..Ochroma Lagopus .....:...<.... 7.3 
ork: 2. '.... (from eork oak, Quercus Cuber) .. 13.7 
Missouri corkwood. Leitneria floridana ............. 18.1 
White pine .......... PURe BOONE oes Ee 23.7 
Cathie; ss Oatalpa speciosa ............... 26.2 
Cypress. 2) Sos s Taxodium distichum ........ cere 6221 
Douglas fir........ Pseudotsuga mucronata ........ 32.4 
Syveamore Ss Platanus occidentalis ........... 35.5 
Hed oak: 32. Querots PUNE a i 40.5 
MS DIG. one AOC BOCCRNOON 6 oa oon eek pee 43.0 
Longleaf pine...... Pind patustria . seo 43.6 
Mahogany.......... Swietenia Mahagoni ............ 45.0 
Locust.os5 358. | Robinia Pseudo-Acacia .......... 45.5 
White oak......... Onereas alec 8 eS 46.8 
Hickory... ... 7°. <p ONY GIDE eas es a ae = 54.2 
Fave CNR Quercus virginiana ............. 60.5 
fronbark - 2.0... 70s Eucalyptus leucorylon .......... 70.5 
Lignum-vitae....... Guaiacum sanctum ............. HD 
BROMY 6 sccsr Ves Diospyrus Ebenus .............. 73.6 
Black ironwood.... Krugiodendron ferreum ......... 81.0 
Until recently it was supposed that the Missouri corkwood 
(Leitneria floridana), small trees of which are growing in 
the Garden, was the lightest. It will be noted that this 
weighs 18.1 pounds per cubic foot as compared with 7.3 
pounds per cubic foot for Balsa wood. Another striking 
comparison is with cork. Ordinary cork weighs about 13.7 
ounds per cubic foot; that is, it is about twice as heavy as 
Balsa wood. 
The ironbark shown in the photograph comes from Aus- 
tralia, and is being extensively imported to the United States, 
particularly for use as rudder posts for ships, where it is 
especially serviceable because of its great strength and 
resilience. 
In Porto Rico and other West Indies, Balsa wood has 
been used probably for a great many years for floats. The 
Consul General of Costa Rica has Uindiy advised that he 
remembers using pieces of Balsa wood during his boyhood 
while swimming, and that there was nothing equal to it 
for that purpose. Prof. Gifford says that in the West Indies 
the natives use it for poles “somewhat as the Chinese use 
bamboo for shoulder poles, tobacco poles, etc., all uses where 
a light, rather strong pole is needed.” 
The physical characteristics of the wood have not yet been 
fully determined. It is extremely soft and can readily be 
indented with the oo nail; is easily cut with tools, planes 
well and is remarkab y uniform in texture. The pieces re- 
ceived at the Garden have no sign of any defects, such as 
knots and checks. Balsa wood has the characteristic uniform 
