It's so nice to see a positive comment about this site for a change!! And yes, plant ID here is faster and more accurate than just about anywhere else you can find. And once you have a plant identified properly, then you can find all manner of references on its growing conditions and behavior........many of which originate from here as well :-)

We as a group so enjoy being able to not only name but as in your case give pertinent info regarding the plant(s). Thank you so much for posting your query here. It helps keep us sharp and I have learned so much about plants I am unfamiliar with.

I've been using a facebook plant ID group for a while now and have the same positive experience learning about this new-to-me zone and the plants in it. Not sure why I don't think about using Gardenweb as my ID resource - just not a habit I guess. But I'd like to bookmark the appropriate forum - can someone link it please? Thanks!

Name That Plant!

I love that forum and the amazing people who are so knowledgeable! I go there often to learn. Just looking and reading you gain so much interesting information. We have so many wonderful, inspiring, intelligent people here on GW.

What?

I love my arum italicum . . . those are sweet surprises when they reappear.

I've not found them invasive at all.

Nancy, this is quite a read. There is a sub-discussion on how herbicides work on woody plants that I found interesting. And updates from people working on the woodland garden that started the conversation.

Arum Italicum - 15 year discussion

You are in a very small minority with that opinion. Venice? Do they give you that Italian ambience?

Invasive plant species seldom show their invasiveness in one's own garden :-) It is when they freely invade natural areas (or croplands) that the problem surfaces.

Having said that, Arum italicum is not considered invasive in CA......a state that has the longest and most detailed listing of invasive plant species of anywhere in the country. It has apparently naturalized a bit but not to the point where it is considered a threat.

Location/regionality is a primary factor with invasive characteristics. I don't imagine SoCal's heat and dryness encourage its spread.

I'm noticing a lot of people in the east having that particular arum pop up in their gardens. It is interesting how regional conditions determine what will be invasive or not. Butterfly bushes aren't invasive here. We hope for vollunteers. Then, of course you have your all star invasive thugs that wreak havoc no matter which part of the country they are in. So this Italian arum is mostly an eastern scourge. Haven't heard any reports of it being in the midwest.

I'm in coastal California, so heat isn't the issue -- the prolonged summer drought of a Mediterranean climate (plus the general droughts we experience in Southern California) inhibit the spread.

If you want invasive in So Cal, try pampas grass or arundo/giant reed or Spanish broom or wild mustard.

Edited to add: Our lack of freezes and extended cold weather encourage certain plants to become invasive.

" your all star invasive thugs that wreak havoc no matter which part of the country they are in. "

Very few of those - location, location, location :-)

" So this Italian arum is mostly an eastern scourge. Haven't heard any reports of it being in the midwest. "

Same as above - location, location, location :-) And it is considered invasive in the PNW as well as the east coast.

GW/Houzz has good users. The forum software is a bit unpredictable but I guess I appreciate that Houzz has found a way to monetize the forums without being SUPER obnoxious (although it could be my browser settings that make it tolerable).

The arums pop up in my yard, but I don't see them in the nearby wilderness areas (east SF Bay coast and hills). Probably too dry? I like them. They aren't around long enough to pull up even if they're in the wrong place. I suspect most people in my neighborhood don't tolerate rogue plants, though.

When I mentioned the Arum's thuggish habits to the OP I did not use the term 'invasive' and I would not use that word if I simply meant it spreads easily in a garden. I do not know enough about the OP's local area to know if A italicum is invasive there in the strict sense of the term.

My warning related only to the Arum's potential to outgrow and crowd out graywings' Sternbergia lutea, not to whether it was an invasive species.

I would not want that Arum anywhere in my yard.