Diachea splendens Peck (1878: 50)

Moreno, G., Castillo, A. & Thüs, H., 2024, Critical revision of Physarales and Reticulariales (Myxomycetes) at the Natural History Museum London (BM), Phytotaxa 644 (2), pp. 79-101 : 95

Diachea splendens Peck (1878: 50)

≡ Diachea bulbillosa var. splendens (Peck) G. Lister , in Lister (1925: 103).

Material studied:— USA. New York: North Greenbush, 6 November 1899, C.H. Peck, box P.15 [ BM001247519 !], corresponding slide s.n. [ BM001247530 !], ex herb. H.J. Howard, [as Diachea splendens Peck , type ex herb. N.Y. St. Mus.] .

The sample studied comes from the type locality (North Greenbush, USA), and was collected by L.M. Peck on dry leaves, like the original material described by Peck (1878), however, the date of collection does not coincide with the date of the original publication, which indicates the month of October and not November. However, the material which we have studied and its substratum is very similar to the leaf iconographed in Plate II of Peck’s work (1878), so it may represent a topotype collected later from the same locality as the nomenclatorial type material.

Diachea splendens is a species characterised by its stipitate sporocarps, with globose sporothecae, and spores with an ornamentation formed by irregular ridges. In Lister’s monograph (1925), G. Lister regarded it as a variety of Diachea bulbillosa and described its spores as “ marked with scattered tubercles, more or less connected by low ridges to form an imperfect reticulation”. The spore diameter according to the original description varies from 0.0003’– 0.0004’ which is equivalent to 7.5–10 µm, although it was not indicated whether spore ornamentation was included. This size is similar to what we have measured in this work. Martin & Alexopoulos (1969) reported a somewhat larger diameter between 10–11(–12) µm due to their inclusion of the ornamentation in the measured diameter.