Howe: Preliminary notes on the genus Usnea 315 



and, so far as I can ascertain, has an approximately coextensive 

 range ; from obtainable data, however, it seems to be somewhat 

 littoral^ though I have examined specimens from the interior of 

 North America. * One from Fayette, Ohio, is dichroic. Some 

 have supposed that strigosa represents an aged condition of 

 florida, but I do not think that this can be proved. I have 

 observed in the field fresh normal specimens of florida in 

 three years grow old and blacken, becoming somewhat ligne- 

 ous, brittle, and abraded, losing in this way their fibrils and as- 

 suming an estrigose appearance, but the short rami, the ample and 

 therefore necessarily crowded apothecia are conditions that cer- 

 tainly in the second instance (short rami) cannot be brought about 

 by age, and are characteristic of certain plants which can be re- 

 ferred only to Acharius' strigosa^ a form o^ florida w^hich may or 

 may not be worthy of recognition — a form, I believe, that repre- 

 sents only an unusually luxuriant condition, brought about by 

 abundant moisture, such as the littoral examples of the Atlantic 

 seaboard, which are affected by fog, and particularly those seen 

 from Mexico (Hidalgo, over 7,000 feet) and other regions of ex- 

 cessive moisture and luxuriant growth. 



Usnea barbata ceratixa (Ach.) Schaer. 



With the filamentous forms the diflficulty of determination is 

 increased threefold,* for immediately a greater similarity seems 

 evident. If we remember, however, that so far we have consid- 

 ered only papillate forms, our work is greatly simplified. It is the 

 present subspecies that I feel sure has caused the greatest per- 

 plexity in the determination of New England Usneas, for if we 

 accept Schaerer*s later diagnosis literally f (see pi. /, Enum. Crit. 

 Lich. 1850), I have seen but three examples of a truly filamentous 

 L/snea from these states bearing large or even middling-sized 

 apothecia. There are distributed in herbaria under this subspe- 

 cies a great many specimens distinctly referable to barbata (sterile 



florida), and more often to 



dasyp 



Throwing out the question of '*apotheciis magnis," which oi course 



*The great luxuriance of Pacific coast specimens, due evidently to abundant mois- 

 ture, if used for comparison, is very misleading. 



f Enum. Crit. Lich. Eur. 3. 1850. See also Nylander, Syn. Meth. Lich. 269, 

 "Thallus aut erectus aut pendulus." 



