ADULTPLANTS
Plants / Oxalidaceae / Purple shamrock / Toxic to cats

Is purple shamrock toxic to cats?

Oxalis triangularis

Yes

Yes. Purple shamrock is toxic to cats, graded low severity by NC State Extension. The agent is soluble calcium oxalates. Call your vet if a cat has eaten any.

Poison severity Low as published by the NC State Extension Gardener Plant Toolbox. Their grade, not ours.
If your cat has eaten some
  1. Take any remaining plant material out of their mouth and rinse the mouth with water.
  2. Call someone. Your own vet first. Otherwise ASPCA Animal Poison Control on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661 — both charge a fee.
  3. Take a photo of the plant, and note roughly how much was eaten and when. It is the first thing you will be asked.
  4. Do not make your cat vomit unless a vet tells you to.

What it does, and why

The agent is soluble calcium oxalates.

Unlike the needle-crystal form, these are absorbed from the gut and bind calcium in the bloodstream.

Signs can appear later than a mouth injury would, and the concern is systemic rather than local.

Worth watching for. Large ingestions can drop blood calcium and strain the kidneys. Treat a big meal of it more seriously than a chewed leaf.

Reported signs

Signs as listed by the ASPCA under Oxalis spp.. Not every animal shows all of them.

What each authority says

What each authority says 2 sources concur
ASPCA — genus-level entry: Oxalis spp.
Toxic to cats and dogs · soluble calcium oxalates
NC State Extension
Poison severity: Low · Soluble calcium oxylates

What to keep instead

Species in this database listed non-toxic to cats and dogs, chosen for a similar look or similar care rather than at random.

PlantFamilyWaterDifficulty
Watermelon peperomiaPeperomia argyreia Piperaceae 7–14d 2/5
Chinese money plantPilea peperomioides Urticaceae 6–11d 2/5

Swapping the plant is the only measure that reliably works. Height and hanging baskets buy less time than people expect with a determined cat.

The other animal

Looking for dogs? See is purple shamrock toxic to dogs. Full care details are on the purple shamrock species entry.

Sources

  1. ASPCA Animal Poison Control — Oxalis spp. Checked 2026-09-12.
  2. North Carolina Extension Gardener Plant Toolbox — Oxalis triangularis Checked 2026-09-12.
  3. Royal Botanic Gardens Kew, Plants of the World Online — Oxalis triangularis Accepted name and family. Checked 2026-09-12.
  4. Wikidata entity Q935848 — entity identity, so this record can be matched against other databases.
  5. Missouri Botanical Garden Plant Finder — Oxalis triangularis Cultivation record. Checked 2026-09-12.
  6. ASPCA Animal Poison Control Center, (888) 426-4435 — emergency line, fee applies

Compiled and edited by Tony Valcarcel · 2026-09-11
Tony Valcarcel is the editor and publisher of this database, not a veterinarian. Severity is reproduced from the authority that published it and is never originated here. How this is sourced.
This page is a reference, not a diagnosis. In an emergency, call rather than read.