Myriophyllum crispatum

Water Millfoil at Monash, ACT

Request use of media

Identification history

Myriophyllum crispatum	9 Aug 2023	JaneR
Myriophyllum papillosum	10 May 2021	JaneR
Myriophyllum papillosum	10 May 2021	michaelb
Myriophyllum crispatum	2 May 2021	michaelb

Identify this sighting

Please Login or Register to identify this sighting.

User's notes

At Isabella Pond.

6 comments

JaneR wrote:

10 May 2021

Hi Michael,
There are two Myriophyllum species in our region that are robust, with erect stems in shallow water. They are very similar !! Defining characteristics are:
Myriophyllum crispatum: crisped hairs on stem, usually;: flowers solitary in axils; female flowers deep red: emergent leaves in whorls of 6-9 and terete.
Myriophyllum papillosum: papillae on stems (usually): flowers in fascicles in axils, female flowers deep reddish purple; emergent leaves in whorls of 4-6, linear sometimes dentate.

The only character clearly visible is that emergent leaves are slightly dentate; possibly they are in whorls of 4-6.
Based on this, then more likely M. papillosum.
Perhaps ther is some drift material on the shore that could give a closer look ?

A bonus is that there seems to be some Marsilea mutica out there as well.

perhaps another opinion ?

michaelb wrote:

10 May 2021

It is 2 months since my visit & I don't have time to return just now. Note that these were planted in the new landscaped arrangement. Your analysis is much more thorough than mine, so I would be happy to accept your suggestion. Otherwise we could go with Myriophyllum sp.

JaneR wrote:

10 May 2021

is there a tick box for "plantings" for these plants ?
it is useful to know for people interested in dispersal mechanisms and invasiveness

michaelb wrote:

11 May 2021

There is no tick box at the moment.

JaneR wrote:

9 Aug 2023

I think this is more likely to be Myriophyllum crispatum.
Reviewing distribution records shows that Myriophyllum papillosum is not a local species.

michaelb wrote:

10 Aug 2023

Thanks Jane