Electronic Flora of South Australia Genus Fact Sheet

Genus URONEMA Lagerheim 1887: 517

Phylum Chlorophyta – Order Ulotrichales – Family Ulotrichaceae

Thallus of slender, unbranched filaments, each basally attached by a conical to discoid, gelatinous holdfast, filaments usually slightly to markedly increasing in diameter upwards, apical cell usually tapering. Cells mostly two to several times longer than broad, with a single chloroplast occupying most of the cell periphery, with 1–4 pyrenoids.

Reproduction: Reproduction (Printz 1964, p. 34) by biflagellate and quadriflagellate zooids and by aplanospores.

Life history uncertain.

Type species: U. confervicolum Lagerheim.

Taxonomic notes: A genus of about 7 species (Chaudhary 1979), all from fresh water or soil.

Uronema is often regarded as scarcely distinct from Ulothrix (e.g. Fritsch 1935, p. 201) but the basal discoid attachment (not rhizoidal) and the relatively long cells appear to separate it satisfactorily (Mitra 1947; Printz 1964, pp. 6, 34; Lee 1978). In the type species and some others the terminal cell has an acuminate tip or is often somewhat asymmetric, but this is not consistently shown in some species (Mitra 1947, p. 360), nor in the Australian species described below. In some species of Uronema, the filaments are rather short compared to Ulothrix, and this applies to the Australian species.

References:

CHAUDHARY, B.R. (1979). Some observations on the morphology, reproduction and cytology of the genus Uronema Lagh. (Ulotrichales, Chlorophyceae). Phycologia 18, 299–302.

FRITSCH, F.E. (1935). The structure and reproduction of the algae. Vol. I. (Univ. Press: Cambridge.)

LAGERHEIM, G. (1887). Note sur l'Uronema, nouveau genre des agues d'eau douce. Malpigia 1, 517–523.

LEE, K.W. (1978). Uronema trentonense sp. nov. (Chlorophycophyta, Ulotrichales): a new edaphic alga from New Jersey. Phycologia 17, 191–195.

MITRA, A. (1947). On the structure and reproduction of Uronema terrestre n.sp. Ann. Bot. n.s. 11, 349–361.

PRINTZ, H. (1964). Die Chaetophoralen der Binnengewasser. Hydrobiologia 24, 1–376.

The Marine Benthic Flora of Southern Australia Part I complete list of references.

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
Part I
©Board of the Botanic Gardens and State Herbarium, Government of South Australia


Disclaimer Copyright Disclaimer Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Department of Environment, Water and Natural Resources