Common name: Swamp Isotome
Isotoma fluviatilis subsp. fluviatilis (R.Br.) F.Muell. APNI*
Synonyms: Hypsela sessiliflora E.Wimm. APNI*
Isotoma sessiliflora (E.Wimm.) Lammers APNI*
Description: Mat-forming, glabrous to sparsely puberulous perennial, rooting at the nodes.
Leaves lanceolate, oblanceolate, elliptic or obovate, 2–15(–19) mm long, 1–7(–9) mm wide, obtuse to acute, margins entire to toothed, petiole 0–2 mm long.
Flowers solitary in the axils, unisexual; bracteoles at base of pedicels minute; pedicels 0.5–35 mm long, glabrous or puberulous. Flowering hypanthium 1.3–3 mm long in females, 1–2 mm long in males, glabrous to minutely pubescent. Calyx lobes 0.5–2 mm long. Corolla (3–)4–8(–11) mm long, white to pale blue, often with deeper blue markings at base of lower 3 lobes, lobes subequal or the upper 2 slightly more deeply cleft, lanceolate to oblanceolate or elliptic, 1.6–4.5 mm long, 0.5–1.5 mm wide, glabrous; tube split to within 1.7–3 mm of base on the dorsal side, glabrous internally or rarely with few hairs. Filaments 1.8–3.2 mm long, distally connate for 0.2–0.7 mm long, adnate to the corolla tube for 0.9–2.2 mm; anther tube 1–1.2 mm long in males, 0.6–0.8 mm long in females, glabrous or very sparsely puberulous dorsally, seta of lower anthers 0.2–0.4 mm long, with a tuft of associated microhairs.
Capsule ovoid, ellipsoid or obovoid, not compressed to slightly compressed, 2.5–5 mm long, 1.5–3 mm wide; seeds (based on a small sample) broadly ellipsoid, slightly compressed, c. 0.35–0.5 mm long, c. 0.3–0.35 mm wide, light brown to yellowish-brown, weakly reticulate.
Flowering: Flowers in spring and summer.
Distribution and occurrence: Grows in wet places around dams and creeks on coastal plains north and west of Sydney, south from Gloucester, sometimes becoming weedy in lawns.
NSW subdivisions: NC, CC, CT, LHI
Text by Entered by Louisa Murray Sep 2016; text by following reference.
Taxon concept: David E. Albrecht , Neville G. Walsh, Richard W. Jobson, Eric B. Knox. (2015) The taxonomic status of Hypsela sessiliflora E.Wimm. (Campanulaceae: Lobelioideae) Telopea Volume 18: 455–462. dx.doi.org/10.7751/telopea9154
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.