42 



Mycologia 



being used in its broader sense to include any fungous growth 

 which produces its ascigerous stage only after a period of rest. 



The order contains approximately two hundred species in the 

 region covered in the present work, which are distributed through- 

 out temperate and tropical America. While many species occur 

 throughout North America, others are found only in the tropics. 



The classification of the order is a question concerning which 

 there are many different views. A single family is usually rec- 

 ognized, and this is divided by Lindau* into six subfamilies. The 

 system adopted in the present monograph corresponds in many 

 respects with that proposed by Lindau, but differs in that peri- 

 thecial and stromatic characters are considered of primary impor- 

 tance in the separation of the order into families and tribes, while 

 spore characters (color, form, septation, etc.) are retained as of 

 generic or specific importance only. 



The genus Nectria as commonly considered includes both stro- 

 matic and non-stromatic species. This difference was recognized 

 by Fries, and has continued to be recognized as a sectional or 

 subgeneric character up to the present time. Dr. M. C. Cooke 

 went a step further and raised Saccardo's subgenus Dialonectria 

 to generic rank, although this is not commonly so recognized. 

 The separation of this genus on the presence or absence of a 

 stroma is here maintained, but since the type of the genus Nectria 

 falls among the non-stromatic species, the name Nectria is retained 

 for those forms, while a new name is proposed for the stromatic 

 species. In recent times, other genera, such as Ophionectria with 

 filiform spores and Calonectria with many-septate spores, have 

 been segregated from the old genus and a separation of Nectria 

 on the presence or absence of a stroma necessitates a similar sepa- 

 ration of other genera in which stromatic and non-stromatic 

 species have been associated. The free (non-stromatic) forms of 

 nectriaceous plants are here brought together in the tribe Nec- 

 trieae. 



With the stromatic and perithecial characters as a basis, the 

 order consists of two well-defined groups, which are here treated 

 as families, each of which is in turn divided into two tribes. The 

 details of this classification are contained in the synopsis given 

 below. 



* E. & P. Nat. Pfl. i 1 : 346. 1897. 



