What is the difference between Calla and arum lily?

Decoding the Lilies: Calla vs. Arum – What’s Really the Difference?

Ever get tripped up by “calla lily” and “arum lily”? You’re definitely not alone! Even folks with green thumbs sometimes mix them up. Both flaunt that elegant, almost sculptural look and belong to the same family, Araceae. But here’s the thing: they’re not quite the same plant. Knowing what sets them apart is super helpful, whether you’re planning your dream garden or just want to avoid accidentally unleashing an invasive species.

Why the Mix-Up?

Okay, so where does all the confusion come from? Well, Zantedeschia aethiopica – a real mouthful, I know – is often called both “calla lily” and “arum lily.” Think of it this way: “Calla lily” is often used for the fancier, hybrid versions of Zantedeschia. “Arum lily,” on the other hand, often points specifically to good ol’ Zantedeschia aethiopica. And just to make things extra interesting, there’s also Arum maculatum, which also gets called an Arum Lily! Confused yet? Don’t worry, we’ll sort it out.

Genus Level: Getting Technical (But Not Too Technical)

Zantedeschia is a genus – basically, a group of related plants – within the Araceae family. So, when you hear “calla lily” or “arum lily,” they’re usually talking about something in the Zantedeschia genus. Arum, however, is a different genus, also in the Araceae family. Related, yes, but definitely not twins.

Cracking the Code: Key Differences

Ready to get down to the nitty-gritty? Let’s look at what makes Zantedeschia aethiopica (that “Arum Lily/Calla Lily”) different from other Zantedeschia species (the “Calla Lilies”) and Arum maculatum:

• Size and Toughness: Zantedeschia aethiopica is a bit of a giant compared to other Zantedeschias. It stands taller and can handle cooler weather – down to about Zone 8, and maybe even Zone 7 if you give it a little TLC in the winter. Arum maculatum is much smaller, usually topping out around 18 inches.

• Color, Color, Color: Zantedeschia aethiopica tends to stick to whites, pinks, and greens. But the hybrid Zantedeschia calla lilies? They go wild with color! You’ll find them in sunny yellows, vibrant oranges, pretty pinks, soft lavenders, and even dramatic dark maroons. Arum maculatum is more subtle, with pale green or purplish flowers.

• Home Sweet Home: Zantedeschia aethiopica is happiest in damp, shady spots. Think pond edges or bog gardens. The other Zantedeschia callas prefer sunshine and well-drained soil. Arum maculatum is a woodland creature, loving shade and moist soil.

• Watch Out! Invasiveness: Here’s a crucial point: Zantedeschia aethiopica can be a bit of a bully in some areas. In places like Australia and California, it can spread like crazy and push out native plants. The other Zantedeschias are generally better behaved. Arum maculatum can also spread quickly.

• Leaf Shape: Arum maculatum has arrow-shaped leaves that are glossy green, often with cool purplish-black blotches.

A Word About Arum maculatum (aka Lords-and-Ladies)

Arum maculatum, also known as “Lords-and-Ladies” (or the less polite “Cuckoo Pint”), is a European native that’s pretty interesting. It has a unique flower structure – a spadix (that poker-shaped bit) surrounded by a spathe (a hood-like leaf). And get this: it attracts pollinators with a stinky, almost fecal smell and by actually heating up! All parts of this plant are poisonous, so definitely don’t eat it.

A Little on the Poisonous Side

Speaking of which, both Zantedeschia aethiopica and Arum maculatum contain those nasty calcium oxalate crystals. So, nibbling on them is a bad idea. It can cause a really unpleasant burning sensation and swelling. Arum maculatum is a pretty common cause of plant poisoning, especially in kids.

The Cheat Sheet: A Quick Comparison

FeatureZantedeschia aethiopica (Arum Lily/Calla Lily)Other Zantedeschia species (Calla Lilies)Arum maculatum (Lords-and-Ladies)SizeTall and proud (2-3 feet)More petiteShort and sweet (12-18 inches)HardinessCan handle a bit of chill (Zone 8, maybe 7)Needs warmer weatherPretty hardy (Zone 7)ColorClassic whites, pinks, and greensA rainbow of options!Green with a touch of purpleHabitatLoves a good soak in a shady spotPrefers sunshine and good drainageHappy in a shady woodlandInvasivenessCan be a bit of a troublemakerGenerally well-behavedCan be a bit of a troublemakerOther NamesPig Lily, Lily of the NileCuckoo Pint