Weeds of National Significance WILLOW IDENTIFICATION Part 3 – male or female Supported by the State Government of Victoria.

Only males produce pollen

Pollen primarily dispersed by bees or wind

Only males produce pollen Several stamens per flower each with a bright yellow pollen sack

Only males produce pollen

Females have bulbous green ovaries Each with a single stigma

Females have bulbous green ovaries

Females have bulbous green * ovaries * May look yellow if water/heat stressed * Turns brown when sheds seed and dries out

Females produce seed What is happening here?

Females shed lots of seed! Pollinations is likely to occur and seed produced if you have: male and female flowers (within approx. 2km) male and female flowers (within approx. 2km) same subgenus (trees or shrubs) same subgenus (trees or shrubs) flowering times overlap flowering times overlap (varies among taxa from Aug to Nov)

Golden Weeping Willow (Salix x sepulcralis var. chrysocoma) New Zealand hybrid willow (Salix alba x S. matsudana) Female flowers Male flowers What is strange about these pictures? Female flowers Male flowers

Seed viability? One willow can produce thousands of seed each spring Must germinate within 1-2 weeks to survive Can germinate within just 6-8 hours! Biggest known culprits – Salix nigra (black willow) Salix cinerea (grey sallow)