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BRYOBARTRAMIACEAE

(R.E. Magill)

The family is monotypic, found only in Australia and South Africa. The family shows similarities to both the Pottiaceae and Encalyptaceae but is maintained as a separate family based on its persistent epigonium.

Bryobartramia Sainsbury

The genus has a single species (B. novae-valesiae (Broth.) I.G.Stone & G.A.M.Scott) found in southern Australia and the southwestern Cape of South Africa.

Plants small, scattered or in small groups, green to yellow-green. Stems erect to 3 mm tall, occasionally branched above; in cross-section without a central strand. Leaves erect-spreading, ligulate, lingulate or lanceolate, 0.3-0.5 mm long; apex broadly acute to obtuse; margins plane, entire; costa subpercurrent or ending below apex: in section guide cells 2, ventral cells large, in single row, dorsal stereid or substereid band 2-3 cells thick; upper leaf cells quadrate to subhexagonal, weakly thickened, with 2-4 C-shaped papillae; basal cells rectangular, thin-walled, smooth; alar cells not differentiated. Paroicous. Perichaetia terminal, leaves linear-lanceolate, 1.8-2.0 mm long. Seta 0.2-0.4 mm long. Capsules cleistocarpic, immersed, globose to oval, apiculate, 0.8 mm long; exothecial cells isodiametric thin-walled, stomata phaneroporic, scattered over urn; epigonia persistent, oval-rostrate, 1.7-2.2 mm long, cells below beak prorate. Spores subround, 35-40 µm, warty, yellow-brown.

Habitat. On clay or sandy soil in open, arid shrubland.

Discussion. The genus might be confused with Goniomitrium, but the narrow papillose leaves and persistent epigonium will help separate Bryobartramia. The epigonium of most mosses splits into two parts as the sporophyte develops, however in Bryobartramia, the epigonium continues to enlarge to accommodate the entire sporophyte. Spores are only released when both the epigonium and capsule walls break down. The epigonium frequently outlasts the capsule.

Literature. Magill, R.E., 1981. Flora of Southern Africa. Part 1 Mosses. Fascicle 1: 269-270. Stone, I.G. 1977. Some morphological and anatomical features of the monotypic genus Bryobartramia Sainsbury (Musci). Australian Journal of Botany 25: 141-157.

accepted 11.06.2003