MISSOURI BOTANICAL GARDEN BULLETIN 11 
new diagnostic characters and completely revises the Amer- 
ican forms. Thirty-six species are Saectibed, twenty-nine of 
which occur from the Gulf States to Brazil. Ten new species 
are established. 
Duggar, B. M., and W. W. Bonns (Ann. Mo. Bot. Gard. 
5 : 153-176) have made extensive tests of the effect of Bor- 
deaux mixture upon the loss of water in various plants. The 
data indicate that while the average water loss of sprayed 
plants is considerably greater than that of unsprayed plants, 
this increased loss occurs largely during the night intervals. 
It is explained on the ground that water loss at this time is 
related to incipient guttation, and this is further confirmed 
by the fact that in plants which generally exhibit guttation 
phenomena transpiration is unaffected by spraying. 
Greenman, J. M. (Ann. Mo. Bot. Gard. 5 : 37-108) has 
continued his monograph of the genus Senecio, and in the 
present publication presents the tomentose forms, bringing 
the total number of species thus far discussed to 131. 
Greenman, J. M., and Norma E. Pfeiffer (Ann. Mo. Bot. 
Gard. 5: 205-210) describe a new Selaginella from Mexico 
which has been designated S. Landi, belonging to the 8. 
i, nd group so widely distributed in the United States. 
oore, George T. (Ann. Mo. Bot. Gard. 5: 211-224) has 
prepared an account of an alga, Gomontia lignicola, a species 
which penetrates wood. The life history of the form has 
been followed and the species has proven to be new. 
Payson, E. B. (Ann. Mo. Bot. Gard. 5 : 143-151) presents 
descriptive notes upon twenty species and varieties of North 
American Cruciferae, the majority of species having been 
recently collected in the Southwest. 
Zeller, S. M. (Ann. Mo. Bot. Gard. 5: 109-118) presents 
extensive data showing the correlation of the strength and 
durability of southern pine, Pinus palustris, and proves es- 
sentially that the stronger pieces of heart-wood are always 
the more durable. Strength is related to specific gravity, as 
previously pointed out, in this case; but this does not apply 
to sap-wood, where decay is rapid irrespective of specific 
gravity. 
Zeller, S. M., and C. W. Dodge (Ann. Mo. Bot. Gard. 
5 : 1-86) furnish a complete account of the hymenogastra- 
ceous genus Rhizopogon in North America. lve Amer- 
ican species are discussed, among which six are new and 
one a new combination. In addition, they describe fifteen 
extra-limital forms, among which two are new. 
Zeller, S. M., and C. W. Dodge (Ann. Mo. Bot. Gard. 5: 
133-142). Following their discussion of Rhizopogon in 
North America the authors have naturally turned attention 
