Species
Nitella opaca
Common Name(s)
Stonewort
Authority
Nitella opaca (Bruzelius) Agardh
Family
Characeae
Brief Description
Small branched submerged plant with easily punctured stems and branches. Distinctive forked branches.
Flora Category
Non Vascular - Native
Synonyms
Nitella flexilis
Distribution
Indigenous. New Zealand: Central North Island. Europe, America.
Habitat
Central North Island lakes.
Features
Aquatic, submerged, macro-algae. Simple, lax appearance (0.3-0.4 m). Regular, once forked branchlets arise in whorls from central stems, which are anchored in the sediment by colourless rhizoids. Stem and branchlets are comprised of strings of single cells that are easily punctured. The branchlet beyond the fork is comprised of single cells. Plant is dioecious, with only female plants encountered in New Zealand and, although contracted fruiting heads form, no oospores have been seen.
Similar Taxa
Like Nitella opaca, N. stuartii has single cells comprising the branchlet beyond the fork, but has an additional branchlet tier at each whorl, compared to the simple whorl in N. opaca.
Fruiting
Conspicuous contracted fruiting heads only bear oogonia. No oospores seen.
Propagation Technique
Fragments only?
References and further reading
Broady, P.A.; Flint, E.A.; Nelson, W.A.; Cassie Cooper, V.; de Winton, M.D.; Novis P.M. Chapter 23 Twenty –Three :Phyla Chlorophyta and Charophyta (Green Algae). In: New Zealand Inventory of Biodiversity (Volume 3), Gordon, D.P. (Ed), Canterbury University Press, 616pp.
Casanova, M.T.; de Winton, M.D.; Karol, K.G.; Clayton J.S. (2007). Nitella hookeri A. Braun (Characeae, Charophyceae) in New Zealand and Australia: implications for endemism, speciation and biogeography. Charophytes (1): 2-18
de Winton, M.D.; Dugdale, A.M.; Clayton, J.S. (2007). An identification key for oospores of the extant charophytes of New Zealand. New Zealand Journal of Botany:463-476
Wood RD, Mason R 1977. Characeae of New Zealand. New Zealand Journal of Botany 15: 87–180.
This page last updated on 7 Jan 2013