18 Plants with Milky Sap: How Safe Are They for Us?

Plants with milky sap are sometimes regarded with suspicion – giant hogweed and oleander come to mind – and rightly so.

A lot of them have toxic chemicals that can irritate upon contact. Let’s look at the plants that we commonly encounter in order to identify if they’re safe for us or not.

A Variety of Plants That Secrete Milky Sap

1. Manchineel Tree

When parts of the tree are cut, they exude a milky white liquid. All parts of the tree contain various toxic compounds that can cause severe skin irritation, as well as other health issues, especially when touched or ingested.

The sap is particularly dangerous because skin contact can cause severe blisters and burns. Worse, the toxins can even cause death.

2. Giant Hogweed

Found in various regions in Europe and North America, the giant hogweed is an invasive plant species. While it is a member of the carrot family, it is not as welcome.

This is due to the strong toxins that are found in the plant, which can irritate humans and animals alike. All parts of this plant are toxic, with the sap being the worst element since it causes severe skin and eye issues.

3. Belladonna

Native to Europe, North Africa, and Western Asia, it is usually found only in carefully curated cultivation in botanical gardens and private collections in North America.

The plant contains a deadly cocktail of toxic alkaloids that cause a wide range of symptoms. In severe cases, the belladonna can cause death in humans.

4. Calotropis

The milky sap of this plant is highly toxic. The sap is excreted by parts of the plant when they are cut or plucked away.

It has been known to cause diarrhea, convulsions, and slow heartbeats. In extreme cases, the sap can even cause death.

5. Euphorbia

The euphorbia milky sap comes out only when parts of the plant are cut or damaged. In extreme situations, getting euphorbia sap in your eye can cause blindness.

When handling the plants as ornamentals, always wear protective clothing, such as gloves, goggles, and face masks.

6. Oleander

All parts of the oleander plant are highly toxic. Its sap can cause skin irritation. Ingesting parts of the plant can cause diarrhea, vomiting, and irregular heartbeat at its most mild.

The worst-case scenario for ingesting oleander parts is death. When pruning this plant, always wear protective clothing and gear.

7. Weeping Fig

The leaf and twigs of the weeping fig can be toxic for animals as they contain oxalate crystals. The symptoms include diarrhea and vomiting. Plus, the milky excretions from the cut or broken parts of the tree can cause inflammation and skin irritations.

Similar to reactions to the milky sap of rubber trees, the symptoms may get stronger when the skin gets exposed to sunlight.

8. Papaya

The milky secretions from the papaya plant and fruit can cause skin irritations. Depending on the skin sensitivity, the reaction can range from mild to severe.

Additionally, the edible seeds contain traces of cyanide. While harmless in small amounts, large amounts can lead to upset stomachs and other worrying symptoms.

9. Frangipani

The sap excreted by the frangipani can be irritating when in contact with the skin. Depending on the individual’s sensitivity, the reaction can range from mild itching to skin dermatitis. All parts of the frangipani are considered toxic.

Ingesting the parts or sap can induce nausea, vomiting, and diarrhea. Its scent can prove tempting to children or pets, so keep this plant away from them.

10. Blue Lily

Due to its beauty, many homeowners fail to remember that the white liquid in the plant stem can be irritating. When in contact with the skin, the individual can experience irritations or even inflammations.

Additionally, the sap can cause the eyes to experience burning sensations. It is most toxic when ingested as it can cause severe mouth ulcers, vomiting, and diarrhea.

11. Small Periwinkle

All parts of the plant are toxic, including the sap. Unlike the campanula white sap, the excreted sap can be harmful when taken in large doses.

In the event that enough has been ingested, symptoms can include nerve problems, hearing difficulties, and hallucinations. It can be tempting for children and pets, so keep them away from this plant.

12. Pain Bush

This plant is known as the African version of the poisonous ivy. However, it is not related as it belongs to another family altogether.

Despite this, this plant has been known to cause the same effects when its sap comes into contact with humans. This can result in muscle weakness, painful blisters, and even blindness.

13. Belladonna Lily

Its botanical name is Amaryllis belladonna, although it is not related to the belladonna plant. It is a toxic lily that looks highly attractive due to its colorful flowers.

However, its sap has been found to be severely toxic to humans. Symptoms include vomiting, diarrhea, drooling, heart failure, and it can even cause paralysis or death.

14. Pencil Cactus

Sometimes called the milk bush or the firestick plant, the pencil cactus belongs to the Euphorbia family. However, it is distinct in its appearance in that it does not possess any foliage at all.

The whole plant looks like it is made up of green branches. When these are broken, the plant excretes an irritating sap that can even cause burns.

15. Common Milkweed

While it is favored by many gardeners for its ability to attract pollinators, it’s not exactly harmless. When parts of the plant are damaged or broken, they secrete a thick sap that can irritate humans upon contact.

Symptoms include nausea, diarrhea, weakness, and even death when ingested in large amounts.

16. Wild Lettuce

Its botanical name is Lactuca virosa. Despite being a distant cousin of cultivated lettuce, this plant is not as beneficial to humans.

When broken or damaged, parts of the wild lettuce can excrete a sap that has known sedative effects. When ingested in large amounts, the plant can cause humans to experience hypnotic, antispasmodic, and narcotic effects.

17. Balloon Flower

While its sap is not exactly poisonous, it can cause varying levels of discomfort in humans. These include stomach cramps, vomiting, and severe diarrhea.

This plant grows mostly in the wild, although homeowners are finding the balloon flower to be a popular garden plant. Keep this plant away from curious children and pets.

18. Arkansas Blue Star

This plant is a member of the dogbane family, which is known to have toxic or poisonous properties. In this case, the Arkansas blue star secretes a sap that is highly irritating to human skin.

It can cause irritation, such as rashes and blisters, depending on the skin sensitivity. When pruning this plant, always wear protective clothing and gear.

Conclusion

It can be difficult to remember that beautiful plants can be toxic, too.

Here are some things you’ll need to keep in mind:

• Milky secretions are one of the ways plants defend or heal themselves from damage.
• Always wear protective clothing and gear when caring for plants with toxic parts or saps.
• When in doubt, always err on the side of caution and avoid touching plants that may be toxic.

If you ever encounter a plant with toxic milky sap found on our list, it’s best to admire it from a distance. 

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