Radiofilum Schmidle, 1894

Holotype species: Radiofilum conjunctivum Schmidle

Original publication and holotype designation: Schmidle, W. (1894). Aus der Chlorophyceenflora der Torfstiche zu Viernheim. Flora 78: 42-66.

Description: Cells mostly arranged in uniseriate unbranched rows embedded in distinct mucilaginous, transversely-stratified sheath. Filaments short and firm or long and flexible. Breakage of cell row sometimes leading to false branching or bi(multi)seriate cell rows. Instead of by a common transverse cell wall, cells sometimes united by gelatinous strands or polar wall thickenings. Transverse striping of mucilaginous sheath especially radiating from lateral cell walls. Cell wall not definite, homogeneous or bipartite in form of two scale-like hemispherical elements giving rise to specific cell division pattern whereby each daughter cell receives one-half of parental cell wall. Cells spherical, ellipsoid or spindle-shaped. Chloroplasts single (rarely two), parietal, laminate or cup-shaped, with 1 or 2 pyrenoids. Longitudinal axis of cells perpendicular to filament. Reproduction by asexual zoospores produced single in ordinary cells and liberated through lateral rupture. Method of sexual reproduction unknown. Radiofilum widespread, planktonic in lakes and swamps; also associated with desmids in soft and acidic waters. Radiofilum difficult to delimit with certainty because changes to circumscription probably based on unrelated specimens. Some algae ascribed to Radiofilum described with bipartite cell wall and cell division similar to placoderm desmids and Microsporaceae. Accordingly, Radiofilum classified to these groups by some authors. Other species assigned to Radiofilum have homogeneous walls and discard parental wall during cell division. Consequently, Radiofilum divided into two groups Radiofilum sensu stricto with type species, characterized by bipartite cell walls; 3-4 former Radiofilum species with homogeneous cell walls transferred to Geminella. That traditional Radiofilum is a heterogeneous assemblage is exemplified by inclusion of an alga with bipartite walls, but in which daughter cells detach immediately after cell division or remain united by intercellular gelatinous strands , forming irregular cell row configurations. This irregularity attributed to non-median gelatinous connections between lower portions of daughter cells (median in Radiofilum); some authors place this species in Interfilum. More meaningful characterization of Radiofilum awaits further comparative light an electron microscopy.

Information contributed by: G.M. Lokhorst. The most recent alteration to this page was made on 2012-01-27 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: John, D.M. (2002). Orders Chaetophorales, Klebshormidiales, Microsporales, Ulotrichales. In: The Freshwater Algal Flora of the British Isles. An identification guide to freshwater and terrestrial algae. (John, D.M., Whitton, B.A. & Brook, A.J. Eds), pp. 433-468. Cambridge: Cambridge University Press.

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=43491

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 27 January 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 27 November 2024