Plants of
South Australia
Triglochin isingiana
Long-spurred Arrowgrass,
Spurred Arrowgrass
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Regional Species Conservation Assessments per IBRA subregion.
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Near threatened
Critically endangered
Data deficient
Coober Pedy
Mount Gambier
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Botanical art

Kath Alcock paintings: 6

Prior names

Triglochin calcitrapum, orth.var., partly

Triglochin calcitrapa, partly

Triglochin sp. B Flora of Australia (P.G.Wilson 4294)

Triglochin sp. B (J.Z.Weber 1330)

Triglochin calcitrapa var. pedunculata

Triglochin elongata, nom.illeg., non Buchenau(1903)

Triglochin calcitrapa var. isingiana

Triglochin calcitrapum, orth.var., partly

Common names

Long-spurred Arrowgrass

Spurred Arrowgrass


Triglochin from the Greek 'treis' meaning three and 'glochis' meaning a point; referring to its three-sided carpels. Isingana named after Ernest Horace Ising (1884-1973), an Adelaide born railways clerk and botanist, who devoted the best part of his life to the study of botany and plant collecting especially in South Australia including the type specimen from Coglin Creek, Central Australia in 1931.

Distribution and status

Found across south Australia, growing on temporarily damp soil in a variety of habitats. Also found in all mainland states. Native. Common in South Australia. Common in the other states.
Herbarium regions: North Western, Lake Eyre, Nullarbor, Gairdner-Torrens, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, South Eastern, Green Adelaide
NRM regions: Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Eyre Peninsula, Northern and Yorke, South Australian Arid Lands, South Australian Murray-Darling Basin, South East
AVH map: SA distribution map (external link)

Plant description

Slender annual herb to 17 cm high. Leaves flat and thread-like, to 9 cm long, shorter than or as long as the inflorescence. Inflorescence erect or ascending, to 9 cm long with the fruiting part at the top to 2 cm long with 6–16 fruits. Flowering between August and October. Fruits are straw-coloured (sometime tinged purple) narrowly pyramid fruit to 7 mm long and 1.2 mm wide just on a short stalk with six seed segments (carpels), 3 fertile alternating with 3 undeveloped sterile ones. Seeds are straw-coloured (sometime tinged purple) narrow wedge-shaped seed to 7 mm long and 0.5 mm wide, with 2 lateral recurved to upcurved spurs to 1.5 mm long at the base. Seed embryo type is linear.

Seed collection and propagation

Collect seeds between September and November. Collect mature fruits either by breaking off individual spikes or by removing plants that are drying off with fruits that are straw-colour and seed segments coming apart easily. Place the fruit spikes in a tray and leave to dry for 1 to 2 weeks. Then rub the dried fruit spikes with a rubber bung to dislodge the seeds. Use a sieve to separate any unwanted material. 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.

Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA23,900 (16.33 g)31-Aug-2016JRG406
North Western
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.
Germination table: