354 CALIFORNIA ACADEMY OF SCIENCES. 



of the genus, the four somewhat unequal perianth seg- 

 ments enclose quite constantly but a pair of opposite sta- 

 mens, not infrequently increased to three in the larger 

 perianths, and more rarely reduced to a single one, and in- 

 stead of very short filaments, they are at maturity exsert 

 beyond the perianth. 



This character is so obvious on the most casual observa- 

 tion, that the only explanation of its having been heretofore 

 overlooked must be the fact that in the specimens from 

 ^hich the descriptions were drawn, the male flowers were 

 either wanting or not examined. 



As the character thus noted serves to give a unique feature 

 to all the various forms of Alniis heretofore includ- 

 ed under these two described species, and is eas- 

 ily recognized in all the specimens accessible to 

 me, including an undeveloped one in the Califor- 

 nia Academy herbarium, collected by Prof. Greene 

 in New Mexico, I am led to the conclusion that all these 

 western forms, varying only in unimportant leaf characters, 

 must be reduced to the earliest described specie?:, Alniis 

 rhomhifoUa, Nutt. ; A. ohlongifolia, Torr., representing the 

 jnost southern and eastern variety. 



Another fact in this connection, coming quite accidentally 

 Tinder my observation — more of morphological than sys- 

 tematic botanical interest — is a singular abnormal condi- 

 tion in which some of the lower staminate aments show a 

 transformation at the summit to regular pistillate flowers. 

 While to ordinary view such a transformation of floral or- 

 gans, involving absolute sterilit}^ and accomplishing no 

 apparent useful purpose in the vegetable economy, may be 

 poetically regarded as a " freak of nature." It is neverthe- 

 less true that by just such abnormal deviations from ordi- 

 nary processes, nature often gives us the clearest insight 

 into her regular plan of operations, though it may need the 

 genius of a Goethe to interpret their real significance. 



The whole subject suggests the value and importance of 

 supplementing or correcting systematic descriptions by 

 careful and intelligent field observations. 



