Fragilariforma rakiuriensis C.Kilroy & K.Sabbe
Deceit Peaks, Stewart Island, New Zealand, M. Charteris, 10 November 1997. CHR 565732.
Isotypes: BM 101033; BRM Zu 5/44; CAS 221054; NIWA diatom collection,
Christchurch, New Zealand (#A6/426).
Institution holding the type material
Stewart Island: Deceit Peaks, open rocky stream at 500 m, pH 5; Table Hill, flowing and standing water, pH 5.2-5.6, EC 100 µS/cm.
Tasmania: Western Lakes, e.g. Sappho Lake, pH c. 6.1, EC 16 µS/cm.
EtymologyMeaning "from Rakiura", one of the Māori names for Stewart Island.
Valves 11-55 µm long, (5.5-)6.5-9 µm wide. Girdle view: narrowly rectangular. Colonies linear. Open girdle bands 2-4, with rows of poroids on edges facing epitheca. Valve view: lanceolate, constricted centrally, with distinctly protracted apices, to rhombic with narrow protracted apices. Constricted-rhombic transition at 22.5-29 µm long. Striae 11-14 in 10 µm, fine, continuous across valve and mantle, approx. parallel but usually irregular, axial break only occasional; areolae not visible in LM. Marginal spines simple tapering hollow tubes on interstriae, absent at apices. Mantle plaques usually absent.
NOTE: abridged to satisfy the publisher's copyright requirements.