132 proceedings: botanical society 



stated that no potable waters in this country have enough iodine to have 

 any effect in preventing goitre, if a lack of iodine is the cause of that dis- 

 ease. Cook quoted his analyses of corals, showing a selective absorp- 

 tion of iodine by these organisms, 



Robert B. Sosman, Acting Secretary. 



THE BOTANICAL SOCIETY OF WASHINGTON 



The 85th regular meeting of the Botanical Society of Washington was 

 held at the Cosmos Club, Tuesday evening, Januar}?- 7, 1913. The 

 following scientific program was presented: 



Dr. David Griffiths : Performances in species of opuntia (illustrated 

 with lantern slides) . This paper will be published in the near future as 

 a bulletin of the Bureau of Plant Industry. 



Mr. J. B. Norton : So7ne interesting facts concerning the genus Asparagus 

 (illustrated with lantern slides). This paper gave a review of features 

 connected with the work of breeding a rust resistant variety of asparagus. 

 Asparagus officinalis has never been found to be completel}^ immune 

 to the attacks of its rust, Puccinia asparagi. Plants nearly immune 

 to the destructive summer stages show no resistance to the aecidial stage 

 of the fungus. Resistance seems to be due to morphological causes. 

 Related species are attacked by the rust but the members of other sec- 

 tions of the genus seem immune. The genus Asparagus and its relatives 

 are entirely limited to the old world, the majority being African. A 

 study is being made of the relationships of this group and many new 

 characters based on the manner of growth, roots, stems, leaf scales, 

 cladodes, etc., have been found. The arrangement of the stomata on 

 the cladodes is very characteristic in the various groups. The old 

 genus Asparagus contains several very distinct groups of species entitled 

 to generic rank. 



Only one hybrid form of known parentage has been secured, a cross 

 between A . officinalis and A . davuricus. Many other combinations have 

 failed to produce seed. Asparagus grows rapidly, — some species average 

 nine inches per day. The seed germination takes from twelve days with 

 officinalis to sixty or more days with some African species. Several new 

 ornamental forms were described. • 



C. L. Shear, Corresponding Secretary. 



