Studies in the Development of two Myriangium Species and the Systematic Position of the Order Myriangiales

SUMMARY

The characters of Myriangium Duriaei and M. Curtisii have been studied in serial sections. The fertile disc in the former arises from one archicarp, and consists of asci and ascogenous hyphae; while in the latter the disc is compound, consisting of several such systems.

The ascal locule cannot be homologized with the locule in the Pseudosphaeriales nor in the Dothideales, because the interthecial tissue is ontogenetically different in each case. So these orders cannot have their roots in the Myriangiales through the monascous locule.

The globose asci, arising from lateral or terminal positions on the ascogenous hyphae, and being separated by these hyphae at different levels, are all characters which indicate a close Plectascales relationship.