LINDBLADIA 153 



^Ethalium thin, very flat, olivaceous or ochraceous, smooth, 

 under the lens punctate, in section showing the columnar or 

 prismatic sporangia, which are normally six-sided, having at the 

 edges six simple threads, the remains of the peridium, extend- 

 ing from base to apex, where the peridium remains intact, arcu- 

 ate ; hypothallus prominent, radiating far around the aethalium, 

 silvery white ; spores in mass, ochraceous, or dull brownish 

 yellow, by transmitted light almost colorless, rough, 9-10 /u,. 



Not rare, on decaying logs, especially of Tilia amcricana, 

 where in the same place successive fructifications follow each 

 other sometimes for weeks together in the latter part of sum- 

 mer and early fall. The sethalium is generally elliptical or 

 elongate, 2-3 cm. in extent, sometimes irregular or branched, 

 varying in color according to degree of maturity, weathering, 

 etc. Plasmodium at first watery, then pink, or flesh-colored. 



Eastern United States ; common. 



C. TUBIFERE^:. 



Fructification aethalioid ; sporangia well defined, tubular, often 

 prismatic by mutual pressure, seated on a common, well-marked 

 hypothallus, at length dehiscent by the irregular rupture of the 

 peridium, in typical cases at the apex, its walls remaining then 

 otherwise entire. 



Key to the Genera of the Tubifereas. 



A. Spores olivaceous ; sporangia in one or several series, i. LINDBLADIA 



B. Spores umber ; sporangia in a single series . . 2. TUBIFERA 



1. Lindbladia Fries. 



1849. Lindbladia Fries, Sum. Veg. Scand., p. 449. 



Fructification aethalioid; the sporangia short, tubular, some- 

 times superimposed, sometimes forming a simple stratum, in 

 the latter case generally sessile, but sometimes short stipitate, 

 the peridium at first entire, at length opening irregularly either 

 at the sides or apex, beset with granules ; spores olivaceous. 



