PRELIMINARY STUDIES ON ANTHOCEROTAE Rudolf M. Schuster Cryptogaraic Laboratory Hadley, Mass. 01035 1, Generic-Subgeneric Limits in Anthocerotaceae Introduction ; In the completion of the last volume of my The Hepati-cae and Anthocerotae of North America for Columbia Univ. fress, ttie MS of which is now in the publisher's hands, a last task was to re-vise the Anthocerotae. My initial treatment of that group was prepared in 1953-56 while I was at Duke University; it underwent substantial revision after study of plants from south Chile, collected in October, 1969; it un-derwent further refinement after study of the New Zealand taxa, first in 1961-62, again in 1976 and 198A. The following attempt at an e-valuation of supra-specific concepts was initially prepared in 1976, after consideration of the Australasian taxa. Philosophical con-cepts for any such attempt derive from the following considerations: (1) No major progress in comprehension of the group will result until the innumerable poorly known taxa are assigned to supraspecific groups. (2) Subfamilial and subgeneric categories are currently un-employed in the Anthocerotales; their utilization will give us ad-ditional "depth" in any hierarchy to be set up. Use of the subgenus category, especially, seems long overdue; its use will also mediate between extreme taxonomic positions. A single example: the taxa placed by Hasegawa (1984) in Folioceros were regarded by Proskauer to be congeneric with Anthoceros s. lat. ( Aspiromitus in the sense of this paper). I here accept an intermediate position and would recognize Folioceros as an autonomous subgenus. (3) Unless and un-til biochemical or other criteria so far undiscovered come to light, our classification must remain "conservative" since morphological and. anatomical criteria — the only criteria currently employed in constructing a classification — are few, and the organisms exhi-bit considerable phenotypic malleability. Indeed, the exceptional architectural uniformity of the Anthocerotae is linked with equal-ly exceptional levels of phenotypic (and probably genotypic) var-iation. Recent study of the spermatids of Anthocerotales thus far fails to reveal significant differences between those of Anthocer-os s. lat. and Nptothvlas (Renzaglia & Carothers, 1986). Re-luctantly, I must conclude that the Notothylaceae are best regard-ed as merely a subfamily of Anthocerotaceae. The classification of the Anthocerotaceae remains a "dark chapter" in part because the approximately 200 binomials have yet to be fully digested. As with, e.g., Riccia , herbarium material is hardly suitable for critical study. Even the generic/suj»generic position of many taxa remains to be established and most will surely 193
BioStor
