Isoetes, from the Greek 'isos, meaning alike and 'etos', meaning year, referring to the submerged species remaining evergreen throughout the year. Muelleri, named after Baron Ferdinand von Mueller (1825-1896), botanist, plant collector and Government Botanist of Victoria.
Distribution and status
Found scattered across South Australia along a band from the north-western corner to the south-eastern corner, growing submerged in rock pools, slow-moving streams and small lakes, where its growth can continue year-round, or in damp soil near temporary water, growing from late autumn to spring. Also found in all States. Native. Uncommon in South Australia. Uncommon in New South Wales. Common in the other States.
Herbarium regions: North Western, Lake Eyre, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Southern Lofty, South Eastern
NRM regions: Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Eyre Peninsula, Northern and Yorke, South Australian Arid Lands, South East
AVH map: SA distribution map (external link)
Leaves erect or somewhat lax, to 30 cm long; apex narrowly cylindrical, gradually wider towards the base, with the base abruptly wider; flattened, loosely overlapping, spoon-shaped, lateral margins pale and papery. Spore structure (sporangia), orbicular to elliptical, to 6 mm long; wall pale, thin. Megaspores are found in the outer leaves; whitish-grey, dimorphic, variable in size and ornamentation; larger spores almost spherical, smaller spores flatter, almost hemispherical, with surface markings on all spores rounded (not angular); few tubercles, markings sometimes absent. Microspores absent; inner leaves sterile. Fruits are megaspores found in the hollow leaf base of the outer leaves. Seeds are white-grey megaspores.
Seed collection and propagation
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-grey megaspores. 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.