BRIEFER ARTICLES 



VARIATION IN HELIANTHUS 



In a recent number of this journal, Dr. George H. Shull' calls 

 • attention to the dark disk found in the wild sunflower of the prairie region, 



4 



but shows that certain material received from that region was heterozygous 

 with a yellow disk recessive. It may be worth while to report that this 

 wild plant does actually produce a yellow-disked Variety, which I have 

 observed both in Colorado and New Mexico. The western sunflower, 

 according to Rydberg, is separable as a distinct specks, Helia it Ih us lentic- 

 nlaris Dougl. This seems to be going too far, and I think it should be 

 called H. annuus lenlicularis . The color of the disk is considered a specific 

 character in Helianthus; but it certainly varies within specific limits, not 

 only in H. anmins, but in H. peliolaris also, as I have shown in Nature, 

 June lo, 1902, p. 174.— T. D. A. Cockerell, Boulder, Colorado. 



ENDOSPERM OF PONTEDERIACEAE 



(with four figures) 



In a recent paper^ on the seeds of Pontederiaceae, Coker makes some 

 references to my paper published in 1898,3 to which I wish to make a brier 

 reply. He says: ''Oddly enough he completely overlooked the interesting 

 pecuHarity in the endosperm of all three genera." The reason for m> 

 overlooking such a peculiarity is clear enough, as a very casual readmg o 

 the paper will show that I made no attempt to follow endosperm formation. 

 My 



m m 



Washington Park, Chicago, the endosperm nucleus almost never divides, 

 and the contents of the embryo sac disorganize without development of 

 endosperm or embryo. 



Some of my slides of Pontederia, however, extend beyond the fertiliza- 

 tion stage, and since Coker's article appeared I have reexamined these, an 

 am able in three cases to confirm his account of a division of the embryo 

 sac into upper and lower chambers. Fig. 3 shows the condition of the 



I Some new cases of Mendelian inheritance. Box. Gazette 45-^^3'^^^' ^^^ ' 

 = CoKER, W. C.» The development of the seed in the Pontederiaceae. 



Gazette 44:293-301. pi. 23. 1907. 



3 Smith, W. R., A contribution to the life history of the Pontederiaceae. 



Gazette 25:324-337. pis, ig, 20. 1898. 



Botanical Gazette, vol. 45] 



Box. 



Bot- 



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