Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Planothidium victori P.M.Novis, J.Braidwood & C.Kilroy

Planothidium victori

Type slide

NEW ZEALAND: Canterbury: Styx River (lat. 43°27.800, long. 172°36.213), periphyton, P.M. Novis and J. Braidwood, 4 November 2009 (CHR618408; cleaned frustules made from culture LCR-S:18:1:1).

Institution holding the type material


Known distribution

Styx River, Christchurch, New Zealand.


Named after Victor Brown, a volunteer co-ordinator of the Styx Living Laboratory Trust water quality monitoring program.


Frustules elliptic-lanceolate in valve view, monoraphid, 14.0-16.5 μm long, 5.0-5.2 μm wide. Frustules rotationally asymmetric to a variable degree in valve view, from almost linear to slightly curved near one pole to incised near one pole to form a hook. Striae transverse to slightly radiate at central area to more strongly radiate at poles, 14-15(-16) in 10 μm, multiseriate. Araphid valve asymmetric at central area where striae are interrupted by a "hoofmark" structure appressed to inner valve surface. Position of hooked pole relative to hoofmark shows that hook can occur at either pole (but never both). Araphid valve slightly convex, raphid valve slightly concave; frustules thus curved in girdle view, 3.6-4.5 μm wide. Raphe straight, with expanded proximal area and terminal fissures curved towards the secondary valve side; internally, central ends are weakly curved. Sternum linear.


Funding from TFBIS (Terrestrial and Freshwater Biodiversity Information System), administered by the New Zealand Department of Conservation, is gratefully acknowledged.


Novis PM, Braidwood J, Kilroy C 2012. Small diatoms (Bacillariophyta) in cultures from the Styx River, New Zealand, including descriptions of three new species. Phytotaxa 64: 11–45.