Two popular house plants were missing in action when government drew up its list of all the plants known to be present in New Zealand, prior to the HSNO Act coming into force in 1998. Monstera standleyana (five holes plants) and Pilea peperomioides (Chinese money plant) were missed off the list and their official status is "new to New Zealand" unless proven otherwise.
Both plants are regularly traded on social media sites but commercial nurseries are reluctant to propagate them for fear of the potential repercussions. NZPPI has been undertaking some work to change their status with officials so they can be sold in New Zealand, though they still won't be able to be imported.
In the case of Monstera standleyana, working with Christchurch Botanic Gardens' curators, we have uncovered a conservatory record which dates back to 1959, and a herbarium voucher of the same specimen made in 1971. The plant was purchased from Anderson's nursery in Napier, a major producer of potted colour and bedding plants back in the day. Undoubtedly many of these tropical houseplants were sold and distributed throughout New Zealand but it is the written evidence that the Environmental Protection Authority need to have in order to make a statutory determination that these plants are "not new". NZPPI is working with Murray Dawson's "Taking Stock" project to present this case to the EPA for their decision.
Pilea peperomioides is in a similar boat. Anecdotally they've been in New Zealand for thirty years or more and many people have them. They came to MPI's attention a few years ago and they were removed from all the sales channels. MPI completed a risk assessment and found it presents a negligible risk to the environment. They're so widespread amongst houseplant enthusiasts that it's really no longer feasible to eradicate them and as long as people aren't smuggling them into the country and just propagating them from NZ stock plants, then MPI are going to direct their energy and limited resources on more important things.
It still leaves us in 'no man's land' with respect to their official status, so NZPPI will apply to change the status of this plant through an Order in Council. There is no charge to do this, but obviously there's no guarantee and the process could take up to 12 months.