Plants of
South Australia
Isoetes drummondii ssp. drummondii
Trilobed Plain Quillwort,
Plain Quillwort
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Regional Species Conservation Assessments per IBRA subregion.
Least concern
Near threatened
Critically endangered
Data deficient
Coober Pedy
Mount Gambier
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Botanical art

Kath Alcock paintings: 2

Common names

Trilobed Plain Quillwort

Plain Quillwort


Isoetes from the Greek 'isos' meaning alike and 'etos' meaning year; referring to the submerged species remaining evergreen throughout the year. Drummondii named after James Drummond (1786-1863), a Scottish born botanist and naturalist who was the curator of the government gardens in Cork, Ireland and an early settler in Western Australia.

Distribution and status

Found on Kangaroo Island, Mount Lofty Ranges and the South-east in South Australia, growing in wet depressions subject to flooding in winter and spring months. Also found in Western Australia, Queensland, Victoria and Tasmania. Native. Uncommon in South Australia. Rare in Western Australia, Queensland and Tasmania. Common in Victoria.
Herbarium regions: Northern Lofty, Murray, Southern Lofty, Kangaroo Island, South Eastern, Green Adelaide
AVH map: SA distribution map (external link)

Plant description

Small freshwater aquatic or semi-aquatic herb with trilobed corm embedded in the soil. Leaves are tufted at the top of the stem, erect or spreading, to 20 cm long, narrowly cylindrical and tapering with the bases abruptly wider, flattened, overlapping and spoon-shaped with lateral margins having paler, papery wings. Spore structures (sporangia), globular, sac-like and found in the hollowed leaf bases. Megaspores are found in the outer leaves, white and tuberculate. Microspores numerous forming dark powdery mass in the inner leaves. This species differ from the other subspecies found in South Australia, Isoetes drummondii ssp. anomala which has bilobed corm, irregularly shaped megaspores (globular or flattened) and no microspores. Fruits are megaspores found in the hollow leaf base of the outer leaves and microspores found on the inside leaves. Seeds are white megaspores and dark powdery microspores.

Seed collection and propagation

Collect seeds between July and November. Check to seed if the plant has any spores by pulling a leaf out of the ground from the base and looking inside the fat, hollow leaf base for a sack of white globular megaspores or dark powdery mass. If present, pull off a few of the leaves and place in a seal paper bags to prevent spores from fulling out. Leave the spores in the paper bag to dry. Then remove the leaf covering carefully to expose the spore sack. Store the spores in an air tight container in a cool and dry place or in a -20oC freezer.