Sagittaria subulata
Family
Alismataceae
Flora category
Vascular – Exotic
Structural class
Herbs - Monocots
Conservation status
Not applicable
Brief description
Small (relatively short compared with other Sagittaria spp. In NZ) aquatic plant that grows in clumps (roesttes) and produces stolons enabling lateral spread.
Distribution
Few field sites in Auckland, Waikato and Tasman.
Habitat
Still and slow flowing water bodies.
Detailed description
Plants stoloniferous, rosette-forming with emegent plants having petiolate ovoid leaves 2-6 cm x 0.5-2 cm. Submerged leaves strap-like 6-60 cm long and up to 0.6 cm wide. Submerged and emergent plants flower with 1 to 10 whorls of flowers, males above female whorls. Flowers 3-petalled, white 1-3.5 cm across. fruiting heads globose, 0.5-0.7 cm across, each with many seeds. Seeds are brown, wedge shaped, 1.5-2 mm long, 1 mm wide, with a characteristic beak.
Similar taxa
Submerged forms similar to other Sagittaria species and Vallisneria australis. All other species have much broader strap-like leaves.
Flowering
Summer
Flower colours
White
Fruiting
Autumn
Life cycle
Seeds. Water dispersed, also deliberate planting.
Year naturalised
1993
Origin
Eastern USA and South America.
Reason for introduction
Ornamental aquarium plant
Control techniques
Not usually controlled in New Zealand, but may be controlled manually, or mechanically.
Etymology
subulata: From the Latin subulam ‘awl’, meaning awl-shaped
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
References and further reading
Kasselmann C (2003). Aquarium plants. Krieger Publishing company, Florida, 518pp.