Isotoma fluviatilis subsp. australis McComb

Swamp Isotome

Contr. New South Wales Natl Herb. 4: 109 (1970) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Mat-forming, glabrous to sparsely and minutely pubescent perennial, rooting at nodes. Leaves oblanceolate to elliptic or obovate, 2–15 mm long, 1–7 mm wide, obtuse to acute, margins subentire to toothed; petiole 0–2.5 mm long. Flowers solitary in axils, irregularly spaced, bisexual, rarely female; pedicels 3–50(–85) mm long, glabrous or minutely pubescent. Calyx-lobes 0.9–2.5 mm long; corolla 6.5–15 mm long, almost white to intense blue or mauvish-blue, lobes sub-equal or the upper 2 slightly more deeply cleft, lanceolate to oblanceolate, 2.5–9(–11) mm long, 0.8–3 mm wide, tube 3–7 mm long, shortly slit; filaments 4–8 mm long, anther tube 1.3–2.5 mm long, seta of lower anthers 0.4–0.5 mm long. Capsule c. obovoid, slightly compressed, 2.5–7 mm long, seeds broadly ellipsoid, slightly compressed, 0.4–0.5 mm long, light brown to brown, weakly and irregularly reticulate.  Flowers Sep.–Jun.; fruits Oct.–Jul.

CVU, DunT, EGL, EGU, GipP, Glep, Gold, GGr, HNF, HSF, LoM, MonT, MuF, MuM, NIS, OtP, OtR, SnM, Strz, VAlp, VRiv, VVP, WaP, Wim. Widely distributed species occurring mainly in seasonally moist depressions.

The two other subspecies recognized by McComb (1970), Isotoma fluviatilis subsp. fluviatilis and Isotoma fluviatilis subsp. borealis McComb, both occur in central New South Wales to southern Queensland.

Source: Albrecht, D.E.; Walsh, N.G. (1999). Campanulaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 4, Cornaceae to Asteraceae. Inkata Press, Melbourne.
Updated by: Daniel Ohlsen, 2016-03-15
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Distribution map


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Isotoma fluviatilis subsp. australis in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Isotoma fluviatilis subsp. australis in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Lowan Mallee present native
Murray Mallee present native
Wimmera present native
Glenelg Plain present native
Victorian Volcanic Plain present native
Victorian Riverina present native
Murray Fans present native
Gippsland Plain present native
Otway Plain present native
Warrnambool Plain present native
Goldfields present native
Central Victorian Uplands present native
Greater Grampians present native
Dundas Tablelands present native
Northern Inland Slopes present native
East Gippsland Lowlands present native
East Gippsland Uplands present native
Highlands-Southern Fall present native
Highlands-Northern Fall present native
Otway Ranges present native
Strzelecki Ranges present native
Monaro Tablelands present native
Victorian Alps present native
Snowy Mountains present native

State distribution

Distribution map
Western Australia
South Australia
New South Wales
Australian Capital Territory