Weeds of National Significance WILLOW IDENTIFICATION An essential skill for effective willow management Part 1 Intro and Part 2 Supported by the State Government of Victoria.

Did you know? Q: How many types of willows are there in the world? Clue: more than 100 have been imported to Australia in the past, so lots more than this. A: More than 300 different species, varieties, cultivars and hybrids > 30 of these are naturalised in Australia New hybrids are forming every day

Willow groupings Genus: Salix (all willows) Salix “tree willows” Chamaetia “alpine willows” Vetrix “shrub willows”

Did you know? Q: What kind of sportsmen would pay top dollar for a bit of willow wood? Clue: If we got one of these players as our ambassador, our motto could be ‘Waugh on willows’ A: Cricket players Cricket bats are made from the cricket bat willow (Salix alba var. coerulea)

Why identify willows? 1.How brittle are the branches? Ease of spread by twigs/branches To prevent the future spread and impacts of problem willows:

Is it a tree or shrub willow? Is it male or female or both? Does it produce viable seed? Ease of hybridisation and spread by seed Why identify willows? * For hybridisation to occur and/or seed produced, you must have: male and female catkins same subgenus flowering times overlap

‘Trees’ VS ‘Shrubs’ Features to look for: form twigs / branches bark leaves catkins (flowers)

single - stemmed multi-stemmed ‘Trees’ - form

upright weeping 10-20m tall at full size

‘Shrubs’ - form always multi-stemmed

‘Shrubs’ always multi-stemmed always multi-stemmed bark rather smooth (but varies with age) bark rather smooth (but varies with age)

‘Trees’ - bark Generally rough or fissured

Tree - twigs/branches Crack more easilyCrack more easily –Break off the twig/branch at its base How easily and cleanly does it break?

‘Trees’ - leaves and catkins Long and narrow leavesLong and narrow leaves Catkins emerge at same time as leavesCatkins emerge at same time as leaves

‘Shrubs’ - leaves and catkins Catkins often emerge before the leavesCatkins often emerge before the leaves Pussy willowsOsiers Both leaves and catkins short and oval-shaped Both leaves and catkins long and narrow Diff from ‘trees’ - often smooth margins along leaf and many stems

Form Is this a tree or a shrub?

Bark

Leaves, stems & flowers

FormTwigs Bark LeavesFlowers

Is this a tree or a shrub? Form

Bark

Flowers and leaves? Is this a tree or a shrub?

Twigs Grey sallow (Salix cinerea)

Shrub willow Is it male or female? Form Leaves? FlowersTwigs Bark