Hakea decurrens subsp. decurrens

Bushy Needlewood at Campbell, ACT

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Identification history

	Hakea decurrens subsp. decurrens	14 Oct 2018	BettyDonWood
	Hakea decurrens subsp. decurrens	13 Oct 2018	BettyDonWood

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13 comments

MichaelMulvaney wrote:

14 Jun 2015

Silke it is pretty hard to tell the invasive decurrens subspecies from that of physocarpa subspecies. This looks like Hakea decurrens subs'. physocarpa. The Flora of NSW identifies the two sub-species by the width of the pod and the width of pale wood when the pod is split in half. decurrens has a 14-19 wide pod and a pale wood zone in the pod of 3-6mm, while physocarpa has a 15-35mm wide pod and pale wood zone of 6-12mm. I leave it to you to confirm

MichaelMulvaney wrote:

14 Jun 2015

Sorry Silke actually Hakea decurrens subs decurrens is the native subspecies and physocarpa the weedy one

SilkeSma wrote:

14 Jun 2015

Thanks Michael, I was indeed wondering how to tell the decurrens apart. I'll go and do some measuring.

SilkeSma wrote:

18 Jun 2015

Hi Michael, I had a look at some pods today. It's not entirely clear cut but but on average I'll go with the physocarpa subsp. The size of the pods is at the low end of physocarpa.

BettyDonWood wrote:

28 Mar 2018

Sorry. I reversed the ID before reading the comments. Though three years down the track, with no other sightings of this subspecies, it might be an idea to find an open pod and redo the measurements. The place to do it is beside the seed cavity.

waltraud wrote:

8 Oct 2018

Given there are large numbers of the local subsp decurrens further north I indeed wonder whether this is physocarpa.
Silke, would you be able to collect the fruits of this specimen? They will open after a couple of days and then you can carry out measurements as suggested by Betty.

SilkeSma wrote:

9 Oct 2018

No problem, I'll get some when I'm over that way next time.

SilkeSma wrote:

14 Oct 2018

I've taken a photo of the seed pods with a ruler next to it. I still can't make up my mind. Over to the experts please.

BettyDonWood wrote:

14 Oct 2018

I cannot remember why I thought it was subsp. physocarpa at the time. Presumably on the diameter of the nuts (follicles according to botanists). Having looked at the pale wood zone of the nuts (usually 6-12 mm wide in physocarpa, usually 3.5-6 mm wide in decurrens) and the outer layer (usually 2.5-5 mm wide in physocarpa, usually 1-2.5 mm wide in subsp. decurrens), and the fact that is extremely unlikely for the coastal subsp, physocarpa to have been planted in the ACT, I have decided it must be subsp. decurrens, the conmon subspecies in the ACT.

MichaelMulvaney wrote:

15 Oct 2018

Thanks for being so persistent Silke and helping us come to the right ID

waltraud wrote:

15 Oct 2018

Great! thanks Silke.

BettyDonWood wrote:

15 Oct 2018

Everyone. The reason both suggested names are subsp. decurrens now and the dates the same is that I merged subsp. physocarpa into subsp. decurrens over the weekend, not realising that the background maintenance was down. Everything went pear shaped. Rohan has said he will try to fix it.

waltraud wrote:

16 Oct 2018

Yes, these kind of things happen when working with huge mega data stuff. We all understand and are very grateful to the CNM background scewing team who work hard to get things running as amazingly smooth as possible.

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