Seeds of South Australia
Isotoma fluviatilis ssp. australis (Campanulaceae)
Swamp Isotome
List of species for Isotoma
Click on an image to enlarge it
Seed collecting:
December to February
Herbarium region:
South Eastern
NRM region:
South East
IBRA regions
Mount Gambier (SVP02)Southern Volcanic Plain
 Rare   (IUCN: RA d(ii))
Bridgewater (NCP01)Naracoorte Coastal Plain
 Regionally Extinct   [possibly extinct]
Glenelg Plain (NCP02) 
 Rare   (IUCN: RA d(ii))
Lucindale (NCP03) 
 Rare   (IUCN: RA d(ii))   [localised]
Wimmera (MDD05)Murray Darling Depression
 Vulnerable   (IUCN: VU D2)   (Probable Decline)   [edge of range]
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Isotoma]
Name derivation:
Isotoma from the Greek 'isos' meaning equal and 'tomos' meaning, a cutting; referring to the equally cut corolla lobes. Fluviatilis from the Latin 'fluvius' meaning river; alluding to the species habitat, growing in water. Australis means of or from the south; referring to the distribution of the species in southern Australia.
Found in the lower South-east in South Australia, growing in moist places. Also found in New South Wales, Victoria and Tasmania.
Native. Rare in South Australia. Common in the other states.
Plant description:
Mat-forming, glabrous to sparsely and minutely hair perennial herb, rooting at nodes. Leaves oblanceolate to elliptic or obovate, to 15 mm long and 7 mm wide, obtuse to acute, margins subentire to toothed. Flowers solitary in axils, irregularly spaced, bisexual, rarely female with white to intense blue or mauvish-blue flowers. Calyx-lobes to 2.5 mm long, corolla to 15 mm long, almost white to intense blue or mauvish-blue, lobes sub-equal or the upper 2 slightly more deeply cleft, tube to 7 mm long, shortly slit, filaments to 8 mm long, anther tube to 2.5 mm long. Flowering between November to January.
Fruit type:
Brown conical-cylindrical  to ovoid capsule, slightly compressed, to 7 mm long,
Seed type:
Dark brown elliptical seed to 0.6 mm long and 0.4 mm wide, weakly and irregularly reticulate.
Embryo type:
Spatulate under-developed.
Seed collecting:
Collect mature capsules, those that are fat, turning a pale straw colour and contain brown seeds. This can be very time consuming as not all capsules will be matured.
Seed cleaning:
Place the capsules in a tray and leave to dry for one weeks. Then rub the capsules gently by hand to dislodge the seeds. Use a sieve to separate the unwanted material. Be careful as the seeds are very small. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.
Seed viability:
From two collections, the seed viability were low to high, ranging from 20% to 90%. This may reflect the maturity of the capsules at collection.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA6400 (0.2 g)50+10-Jan-2008TST353
South Eastern
19-Sep-200820%+5°C, -18°C
BGA9600 (0.596 g)100+13-Dec-2007TST293
South Eastern
19-Sep-200890%+5°C, -18°C
Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.
Number of plants: This is the number of plants from which the seeds were collected.
Collection location: The Herbarium of South Australia's region name.
% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.