pg . 80
NQ DRY TROPICS WEED FREE
DELTA ARROWHEAD OR SAGITTARIA
Sagittaria platyphylla
DELTA ARROWHEAD OR SAGITTARIA
WATER WEEDS
DESCRIPTION
Sagittaria is a perennial aquatic herb with both a submerged and emergent form .
Leaves Glossy green , broadly elongated 280 x 100mm borne on erect stalks to 800 mm long , triangular in cross-section with a prominent parallel vein . While submergent leaves are thin and strap-like , 500 x 20mm .
Flowers appear from the base on a leafless erect stem with three white petals and yellow centers .
Fruit is a 5-10 mm wide cluster of tiny one seeded segments .
Roots are underground stems ( rhizomes ) which commonly develop underground tubers 40cm long and 15mm wide
Habitat Grows in still or slow-flowing permanent freshwater , such as lagoons , dams , bunded watercourses , irrigation channels , drains and rivers .
Weed characteristics Capable of rapid growth and colonisation reducing the efficiency of irrigation networks and affecting stream health and biodiversity . A single plant produces up to 20,000 seeds .
Dispersal Spread by seed , rhizomes , tubers and floating entire plants . Cultivated as an ornamental .
BIOSECURITY MATTER
This species is listed as a Weed of National Significance ( WONS ) and is under a regional containment program .
HOW TO ACT
All suspected plants must be reported to NQ Dry Tropics . Don ’ t sell or buy this plant through online aquarium trade networks . Don ’ t release aquarium plants , soil or water into natural waterways . Recreational water users should maintain a high standard of vessel hygiene at all times and washdown wherever possible .