2006 Volume 100 Pages 53-67
The salient features of Xenothallus vulcanicola R. M. Schust. are illustrated, including details of gemma, conducting strand, and gynoecial anatomy. In addition, the sporophyte generation of Xenothallus R. M. Schust. is described for the first time, based on samples collected from a population of this taxon from Arthur's Pass, South Island, New Zealand. The sporophytes, which matured in a vermiculite culture of the plants, closely resemble those found in Symphyogyna undulata Colenso and Greeneothallus gemmiparus Hässel. The capsule is short cylindric, with an apical mamilla, the capsule wall is 2-layered, the elaters are 3 or 4 spiralled and occasionally branched, and the distal spore wall is ornamented with densely packed, thick, truncate lamellae. These findings provide morphological evidence congruent with recently published molecular analyses that resolve Xenothallus and Greeneothallus Hässel nested within Symphyogyna Nees & Mont.
