Previous descriptions of Dicranolejeunea axillaris (Nees & Mont.) Schiffn. lack details of the sporophyte anatomy and shoot-sporophyte relationship. A study of serial sections shows that the sporophyte develops entirely within the enlarged calyptra and does not penetrate the gametophyte axis. The foot is highly reduced, consisting of only a few cells, and the seta is articulate and of Schuster's (1966) Brachiolejeunea type. The capsule wall is two-layered and has extensive fenestrate thickenings on the inner tangential wall. The elaters are unispiral and remain attached to the capsule valves after dehiscence. The spores are papillose, lack the rosette markings usually found on Lejeuneaceous spores, and undergo precocious germination in the capsule. In general, the sporophyte phase of the leafy hepatics is fairly conservative, often undergoing only slight diversification from one genus or family to the next. This overall uniformity of sporophyte characters within a genus and/or family as well as the frequent inaccessibility of the sporophyte phase has often led to the omission of or only cursory treatment of details of the sporophyte anatomy and shoot-sporophyte relationship. Actually, however, because of this apparent stability, the characteristics of the sporophyte are extremely important as criteria for the more natural delineation of genera, families, and perhaps even suborders. As Schuster (1966) has aptly demonstrated, many more data are needed on the fine anatomy of the sporangia in order to solve some of the perplexing problems of liverwort taxonomy. Certainly, one of the more disconcerting families in which such data may prove valuable is the complex Lejeuneaceae, in which detailed investigations of the sporophyte and shoot-sporophyte relationship are more frequently lacking than present. A study of these structures in D. axillaris (Nees & Mont.) Schiffn., the type species of the lejeuneaceous genus Dicranolejeunea (Bonner, Bischler & Miller, 1961), is considered to be particularly significant since this species has what seem to be more or less primitive characters for the family and for the tribe Holostipae, namely, athecal or collarless branches of the Frullania and Radula types with a lack of branches of the Lejeunea type (Crandall, 1969), a three-keeled Mastigolejeunoa-Lepidozia-type perianth as defined by Schuster (1966), and a simple Stictolejeunea-type sporeling (Fulford, 1956). Although a few sporophyte characters have previously been reported for this genus (Spruce, 1884; Mizutani, 1961), many valuable aspects of the sporophyte anatomy and shoot-sporophyte relationship have been neglected. 1 We thank Dr. Margaret Fulford for the use of her library and herbarium materials. 2 Department of Botany, University of Wisconsin, Milwaukee, Wisconsin 53201. 3 Cell Research Institute and Department of Botany, University of Texas, Austin, Texas 78712. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:22:36 UTC All use subject to http://about.jstor.org/terms 388 THE BRYOLOGIST [Volume 72