T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Schoenoplectus californicus (California bulrush)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Cyperaceae
Genus: Schoenoplectus
Species: S. californicus
Binomial name: Schoenoplectus californicus
Synonyms: Scirpus californicus
Common names: California bulrush, Southern bulrush, Giant bulrush

Schoenoplectus californicus is a very aggressive invasive perennial sedge with knotty rhizomes and inhabits marshy areas, coastal river banks and estuaries. It is native to the southern and western United States as well as Mexico, Central America, South America, Easter Island, and the Falkland Islands. It is now naturalised in New Zealand. In New Zealand it is restricted to the Waikato River delta area, Northern Wairoa River and has been widely planted (usually in error as people thought it was the indigenous S. tabernaemontani) for use in wetlands treating effluent. The native S. tabernaemontani  has bluish-green stems and erect flower stalks that do not droop.
It is spreads in many ways including water, wind, contaminated soil and feed, machinery, wildlife and it forms dense beds that colonise mobile sand deposits and river margins where it displaces native sedges by out-competing and suppressing their growth.
Schoenoplectus californicus has bright-green stems, growing up to 3 m tall. The stems (culms) are terete (circular) in the lower third to half and trigonous (triangular cross section) in the upper 2/3 to half. Its leaves form sheathing bracts (about 30 cm long) at the base of the stems. This sheaths becomes loose and papery.\
During November to April it has a pendant inflorescence of cream to grey nut like seeds (2.9 mm long) on the stems tip.

For more details download a published article by Peter J. de Lange, Rhys O. Gardner, Paul D. Champion & Chris C. Tanner (1998) Schoenoplectus californicus (Cyperaceae) in New Zealand, New Zealand Journal of Botany, 36:3,319-327
http://dx.doi.org/10.1080/0028825X.1998.9512573