488 Durand : Classification of the Fleshy Pezizineae 



The inner excipular layer is made up of long, slender, hyaline 

 threads which continue upward to form the inner part of the mar- 

 gin. The hypothecium is thin and obscure. 



Beloniella Dehnii (Rab.) Sacc. PI. 32, Fig. 17 



This plant is parasitic on the stem and petioles of Potentilla 

 As in other Mollisiaceous plants, the hypothecium is little prom- 

 inent. The excipulum resembles that of Pscudopeziza trifolii. It 

 is made up of polygonal cells, 10-12 /j. in diameter. The inner- 

 most cells have thin, hyaline walls, but toward the surface they 

 become thicker and dark brown in color. The excipular tissue is 

 continuous at the base with the intercellular nutritive mycelium. 



Orbilia vinosa (A. & S.) Karst. PL 32, Fig. 16 



The plants of this species are small and gelatinous, becoming 

 contorted when dry. The cups are sessile, smooth, with a clear 

 wine-purple color. The species represents a group which was 

 formerly placed in the Bulgariaceae. Rehm,* however, suggested 

 that on the basis of excipular structure they approach mostly the 

 division Mollisiaceae, and should, perhaps, be united wholly with it. 

 Schroterf there foreunited the most of Rehm's Callorieae to the 

 Mollisiaceae, in the same way that he did the Bulgarieae to the 

 Helotiaceae. 



In Orbilia vinosa the hypothecium is poorly developed. The 

 excipulum has two layers. The inner one is composed of fine, 

 closely interwoven hyphae. The outer layer consists of iso- 

 diametric cells, 9-12 ji in diameter with thin walls. It forms a 

 stratum three to five cells thick over the whole exterior of the cup. 



Reviezv of the Mollisiaceae. — It will be seen that both prosen- 

 chyma and pseudo-parenchyma are found in this family. The 

 former tissue when it occurs resembles that of the Helotiaceae. 

 The latter is always present and forms the principal sterile tissue 

 in the family. Except in the gelatinous group, the cells, at least the 

 outer ones, have thick brown walls. This is a striking character- 

 istic of all the Mollisiaceous plants. There seems to be no struc- 

 tural reason why Orbilia should not as well be united with the 



*Rehm, p. 445. 



f Schroter ( l), p. 120; (2), p. 217. 



