44 



Mycologia 



Tribe i. Nectrieae 



Perithecia free (without stroma) and occurring singly but 

 often gregarious and occasionally more or less crowded on the 

 surface of the substratum, or formed beneath the epidermis and 

 becoming erumpent-superficial, smooth, verrucose, or clothed with 

 deciduous mycelial threads or well-developed hairs; asci cylin- 

 drical to clavate or subovoid, 4-8-spored; spores simple or com- 

 pound, globose to filiform, hyaline or colored ; conidial phase 

 never forming a stroma. 



Spores hyaline. 



Perithecia subepidermal, becoming erumpent-super- 

 ficial. 



Spores simple. i. Hyponectria. 



Spores septate. 2. Nectriella. 

 Perithecia superficial on the substratum. 

 Spores simple. 



Spores appendiculate ; perithecia beaked. 3. Eleuthromyces. 

 Spores without appendages ; perithecia not 



beaked. 4. Pseudonectria. 

 Spores compound, i-many-septate. 



Spores i-septate. 5. Nectria. 

 Spores more than i-septate. 



Perithecia light-colored, yellow or red. 



Spores elliptical to fusiform. 6. Calonectria. 



Spores filiform or subfiliform. 7. Ophionectria. 



Perithecia dark-colored, blue. 8. Gibberella.* 

 Spores dark-colored, brown or blackish. 

 Spores simple. 



Spores subglobose, rough ; perithecia subglobose. 9. Neocosmospora. 



Spores elliptical, smooth ; perithecia flask-shaped. 10. Melanospora. 



Spores compound, 1 -septate. 11. Letendraea. 



i. Hyponectria Sacc. Michelia 1 : 250. 1878 



Perithecia globose or subglobose, subepidermal, often becoming 

 erumpent ; asci 8-spored ; spores elliptical or subelliptical, hyaline, 

 simple. Distinguished from Nectriella by the simple spores. 



Type species : Sphaeria Buxi DC. 



Spores 5-6 X 1.5-2 mic, on stems of Opuntia sp. 1. H. Cacti. 



Spores 10 X 2-2.5 mic, on herbaceous stems. 2. H. dakotensis. 



* See Creonectrieae. 



