Psilosiphon scoparium Entwisle
“Plants occurring inclumes of some 10-20 erect axes subtended by a firm basal cushion of uniseriate filaments. Erect plants are olive-green, cylindrical, and 14-33 mm long by .5-1.5 mm in diameter. Axes producing short lateral branches only rarely and having smooth srfaces without nodulation, .5-1.5 mm in diameter. Each axial cell produces four periaxial cells and successive periaxial cells are orthositchous. The periaxial cells further divide and differentiate to produce longitudinal medullar filaments which then give rise to radial cortical filaments. Attachment rhizoidal filaments arise from the periaxial cells in the basal peortion. Ascending and descending medullar filaments derived from the axial cells do not densely surround the axial cell. Ultimately, the medulla becoming a mass of tangled medullar filaments, up to several hundred in cross-sections of mature axes, each 7-15 mm in diameter, enveloping a thick-walled (to 5 mm), axial cell, ca. 23 mm in diameter. Medullar filaments producing lateral, initially short, fascicles from an intermodal portion of the cell. The cortex appearing to be mostly adventitious and is relatively cohesive and firm, condidting of filaments 4 or 5 cells long and pseudo- di- trichotomously branching. Cortical filaments are sometimes terminated with a unicellular hair up to 60 mm long. In older plants, continuing growth of the cortical filaments resulting in numerous free-standing series, up to 12 cells long, of ellipsoidal cells. Inflated cells, 12-20 mm in diameter and 16-28 mm long often forming at th end of the external filaments and resembling chains of sporangia, but evidence of spore release no present. Adventitious plantlets, however, arising directly from some of these exogenous filaments, both as direct extension of attached filaments and on those which broken off in culture. In older plants, clumps of new multiserate plants sometimes arising from the thallus surface. “
Kumano, S. 2002. Freshwater red algae of the world. Biopress Ltd. 375pp.
Type Locality: Australia.
Distribution: Australia, New Zealand.