Hi Waltraud. I confirmed on your certainty. If you are having a problem with your confirmations, it is probably best to communicate directly with Aaron, rather than using the comments, which are not always seen.
PS. The reason you are having trouble with confirmations is that the area of your reporting does not seem to be part of the Mount Majura Nature Reserve. This report is for Hackett.
The ACT Census of Vascular Plants lists Ludwigia peploides subs. montevidensis (Onagraceae) as an exotic plant; PlantNET lists the species as native for ST; see http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=in&name=Ludwigia~peploides~subsp.+montevidensis.
Hi Waltraud, This is a difficult one, PLantNET indicates this plant was collected in Australia in 1803. However, the plant was first described in 1825 as Jussiaea montevidensis from a collection in Montevideo (Sprengel, C.P.J. (1825), Systema Vegetabilium Edn. 17, 2: 232 which can be accessed online at the Biodiversity Heritage Library). Later work by Raven, P.H. (1963), The old world species of Ludwigia (including Jussiaea), with a synopsis of the genus Onagraceae). Reinwardtia 6(4): 395, places it as a subspecies in Ludwigia peploides. Unfortunately while this paper appears to be online the PDF cuts out before it gets to page 395. You might have to contact the ANBG if you want to resolve this issue. Ken
You will notice another sighting from Bodalla NSW. This belongs to Betty Wood. She has it as native in her book III of Flowers of the South Coast and Ranges of NSW.
I used the Flora of NSW decision that is is native when that book was published. Plantnet did not exist at that time. I don't know the basis of the decision to call it Introduced in the ACT. ACT could well be outside its natural range.
Thanks everyone. I contacted the ANBG reg the reason to list the species an "Exotic" in the Census given that PlantNet NSW list it native for the Southern Tablelands. Here is the reply from the manager of Botanical information:
The listing of Ludwigia peploides subsp. montevidensis in the ACT Census as “Exotic [EA]” (a taxon introduced to Australia and the ACT (i.e. extra-Australian)) is incorrect. The earliest ACT specimens in the Australian National Herbarium were collected in 1984, so it’s not entirely clear whether it has become naturalised from outside the ACT (e.g. from NSW, where it is regarded as being native) or was overlooked earlier. Given some of the intensive plant collection activity in the ACT in the 1960s and 1970s we might lean towards the former explanation but it’s not really possible to be sure.
This will certainly be corrected in the next edition of the ACT Census, so thank you again for drawing it to our attention."
Strangely the species has now been entirely removed from the new Census of vascular plants. I shall collect a specimen for the Australian herbarium. Waltraud