The temperature's been warm, the sun was sighted (a bit) over the weekend, and Memorial Day brings the unofficial start of summer. That can mean only one thing:

It's giant hogweed time!

You can have your summer Ozone Action Days, which seem as routine as a Pittsburgh election with no Republican candidates. To obtain a sense of menace without shelling out $8 for yet another "Terminator" installment, we much prefer a good giant hogweed infestation alert like the one issued by the Pennsylvania Department of Agriculture Friday.

Priding itself on its urban roots, The Morning File never previously even heard of giant hogweed (or of the Department of Agriculture, for that matter, which sounds so 1800s retro) despite at least four previous references in the Pittsburgh Post-Gazette. (Hey, who has time to read these days anyway? Here's one.) Forgive us for thinking hogweed was connected to swine flu, as maybe just something pigs rolled around in when they felt achy.

We might comprehend it better if the city neighborhoods provided us with sightings of some tamer version -- a modest hogweed -- the way city-dwellers sometimes have unkempt front yards to prepare you for going to the country to see property overflowing with rusted appliances and trucks.

The latest giant hogweed sighting was in Evans City. That's right, the same area the zombies flooded in George Romero's "Night of the Living Dead." (Coincidence? We think not.)

In sending a warning to all residents (our own warning: Morning File hyperbole alert) to stay inside, lock doors and tear apart furniture to use the wood to board up the windows, the ag department called giant hogweed "a noxious and invasive weed that can cause blistering and scarring on the skin of susceptible people."

Susceptible people? Who's that?

Am I susceptible? How do I know? Is it based on my size, my skin complexion, or willingness to go along with whatever a plant tells me ("Feed me! Feed me!")? Should I call the Giant Hogweed Hotline? What, are you kidding me, Pennsylvania really has a Giant Hogweed Hotline? (Yep, 877-464-9333, but how'd we get that hotline before one for reporting excessive legislative perks?)

Operator: Hello, Giant Hogweed Hotline here.

Caller: Yes, I'd like to report an infestation.

Operator: Are you blistering? Can you give me the location?

Caller: Well, that's a pretty personal question. Do you, by any chance, have a urologist on duty?

Operator: No, sir, I meant the location of your giant hogweed. Where is it?

Caller: Oh. Yes, it's in my living room here in Butler County. I took some off the side of the road to pot it after my other houseplants died. I'm terrible with plants, usually. This guy's growing great though. He's a monster. You should see it.

Operator: Sir, we don't really recommend domestication of giant hogweed.

Caller: Are you suggesting it might harm my pet python? Do you have a herpetologist on staff who can offer advice?

Operator: I'm afraid it's just me and the other 20 giant hogweed phone bank operators standing by to take your calls.

Caller: Do you get a lot of giant hogweed calls?

Operator: More than you would think.

Caller: I'm guessing that means, like, three this year then?

Operator: Uh huh.

The good news in the giant hogweed scourge is its economic benefit in these trying times.

The Agriculture Department has to employ staff to try to eradicate it, spraying with the kind of chemicals you can't find in the hardware store. ("I just love the smell of giant hogweed killer in the morning.")

The agriculture officials say there are 274 "active" giant hogweed sites across the state, which presumably means they're on the move, heading toward my front door and yours.

It is possible that if we all work together, using immense powers of detection (actually, the danged thing grows over 10 feet tall, so it's not exactly like looking for Osama bin Laden), the giant hogweed plague will end before our grandchildren's grandchildren are scarred by it.

Til then, let's get the best scare out of it we can.