The Sporophyte and Sporeling of Bryopteris filicina (Sw.) Nees

Abstract

The shoot-sporophyte relationship, sporophyte structure, and sporeling pattern of the liverwort Bryopteris filicina were studied in serial sections. As has been recorded for other members of the Lejeuneaceae, the sporophyte of B. filicina develops entirely within the enlarged calyptra. The foot is simple and lacks a collar. The seta is articulate, and in transverse section is of Douin's general type, a type which differs from that usually found in the Lejeuneaceae. The two-layered capsule wall has characteristic thickenings, the elaters are unispiral, and the spores are marked with distinct rosette patterns. Sporeling development from a globose protonema within the exospore is of the Frullania type. Bryopteris filicina (Sw.) Nees, the type species of the tropical genus Bryopteris, belongs to the tribe Holostipae of the family Lejeuneaceae. The mature plant consists of a prostrate caudex with scalelike leaves from which arise erect, freely branching, leafy stems or axes. The underleaves on these leafy axes are undivided, as is characteristic of the Holostipae, and the leaves are complicate-bilobed with a large ovate dorsal lobe and a small, inflated, ventral lobule. The female inflorescence is borne on a special, short, lateral branch without vegetative leaves (Fig. 1). In contrast to the single series of female bracts and bracteoles common in most members of the Lejeuneaceae, B. filicina has three to four series of bracts and bracteoles, all of which differ from the vegetative leaves (Fig. 1, BR, BE). In both bracts and bracteoles there is a gradual increase in size and marginal configuration from the small, appressed, basal series to the large, spreading, innermost series. The lobes and lobules of the bracts are acute in the basal series, long acuminate in the inner series. The basal bracteole is small and undivided, while the innermost bracteole is as long as the innermost bracts, is keeled, and is divided halfway into two equal, long, acuminate lobes, coarsely toothed along the outer margin. The mature perianth, which is mostly concealed by the innermost bracts and bracteoles, is more or less oblong in outline and has three sharp keels, two lateral and one ventral (Fig. 2). In all previous descriptions of B. filicina, no details of the sporophyte structure, the shoot-sporophyte relationship, or sporeling development have been included. SPOROPHYTE STRUCTURE Serial sections were made of material collected by George S. Bryan3 in 1923 in Huanuco, in the vicinity of Mufia, Peru, and preserved in formyl-acetic alcohol in the 1 Part of a thesis submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of Master of Science. I thank Dr. Margaret Fulford for her help in this study. 2 Department of Biology, University of Cincinnati, Cincinnati, Ohio 45221. 'After Dr. Bryan's death this material was sent to Dr. Fulford by Dr. Iltis of the University of Wisconsin, and it is now at the University of Cincinnati. This content downloaded from 157.55.39.217 on Mon, 18 Apr 2016 06:36:53 UTC All use subject to http://about.jstor.org/terms 424 THE BRYOLOGIST [Volume 70