scolecopteris

Hairs on sporangia are a typical feature of 5 of the 15 Scolecopteris species distinguished by Millay [1]. They are assumed to be completely absent on the sporangia of the “Maggot Fern” from Doehlen basin, Sc. elegans. In view of the several pieces of evidence lately accumulated which indicate the presence of more than one Scolecopteris species at the type locality of Sc. elegans it is not surprising that, among the hundreds of chert samples cut and polished in the latter years, hairy sporangia have been discovered in two of them (Fig.1 & Fig.2).

It is not obvious how to interpret these observations. The hairs could be an incidentally re-activated old feature inherited from hairy ancestors but normally suppressed in Sc. elegans, or else they could indicate the presence of other species. Anyway it is worth while trying to relate the finds to the 5 hairy species listed below. *

						Fig.1: cross-section of a synangium with hairy sporangia
						Fig.2: Sporangium tips with hairs

The synangium cross-section in Fig.1 is compatible with Sc. minor but not with the others: Sc. latifolia looks quite different according to a picture in [1], the sporangia of Sc. mamayi have the hairs only at their tips, those of Sc. monothrix have only one very long hair each, and also the hairs of Sc. vallumii are much longer. The sporangia with two hairs each near the tip as seen in clear chalcedony in Fig.2 do not seem to fit onto any of the hairy species: Pinnules with forked veins have been found near the sporangia, most probably being related to them. This excludes Sc. mamayi, which is said to have non-forked veins. Again, Sc. monothrix and Sc. vallumii can be excluded because of the length of their hairs. The existence of two types of hairy sporangia adds to the evidence hinting at the presence of other species at the type locality of Sc. elegans. (See also the contributions on forked pinnule veins.)

Hairs on Scolecopteris sporangia