Ornamental Sweet Peas (Lathyrus odoratus)
Of all the pea varieties, the most common one mistaken for edible peas is the ornamental sweet pea (Lathyrus odoratus). These beautiful, fragrant flowers are a popular choice for gardens and bouquets but are toxic to humans and animals. All parts of the plant are considered poisonous, with the highest concentration of toxins found in the seeds.
The primary danger with ornamental sweet peas comes from neurotoxins known as lathyrogens. Ingesting large quantities of the seeds over an extended period can lead to a condition called lathyrism. Symptoms of lathyrism can include neurological damage, paralysis, tremors, and convulsions.
It is important to note that sweet peas belong to the genus Lathyrus, while edible garden peas are in the genus Pisum. This botanical difference is the key reason for the toxicity. Some varieties of Lathyrus are cultivated for human consumption (such as grass pea, Lathyrus sativus), but even these can cause health problems if they constitute a significant portion of a person's diet over a long time. The average gardener should always treat ornamental sweet peas as strictly for display. For more information on plant identification, consulting a reliable source like the North Carolina Extension Gardener Plant Toolbox is highly recommended.
Rosary Pea (Abrus precatorius)
Another extremely dangerous pea variety is the rosary pea (Abrus precatorius), also known as jequirity bean. While not commonly found in garden centers, it grows as an invasive species in many tropical and subtropical regions. The seeds of the rosary pea are highly distinctive, featuring a bright red color with a single black spot. Despite their attractive appearance, they contain abrin, one of the most potent plant toxins known.
Unlike sweet peas, where accidental ingestion of a single seed is unlikely to be lethal due to the tough seed coat, the rosary pea is far more dangerous if the seed is chewed or broken. Abrin is a fast-acting poison that can cause severe gastrointestinal distress, organ failure, and even death. Because of their colorful nature, rosary peas are sometimes used in jewelry, such as necklaces and rosaries, which poses a significant risk if the beads are broken or ingested by children or pets.
Inedible Pods of Edible Peas
Not all inedible pea parts come from entirely poisonous plants. The fibrous pods of certain edible pea types, commonly called English or shelling peas (Pisum sativum var. sativum), are too tough to eat. Unlike snow peas or sugar snap peas, which have been bred to have tender, edible pods, English peas have a parchment-like layer in their pods that is indigestible. When preparing these peas, the pods must be shelled and discarded, and only the sweet peas inside are cooked or eaten.
How to Identify Edible vs. Inedible Peas
Visual identification is crucial for garden safety. Distinguishing between edible and inedible peas can often be done by examining the plant's physical characteristics, such as the stem, leaves, and pods. Never consume a pea plant unless you are 100% certain of its identity.
- Stems and Leaves: Edible pea plants have round, succulent stems and larger leaves. Ornamental sweet peas, on the other hand, typically have slightly flattened or winged, rougher stems and smaller leaves.
- Flowers: Edible pea flowers are usually white or purple, but their primary purpose is pollination, not visual appeal. Sweet pea flowers, however, are renowned for their beauty and come in a wide range of colors with a strong, sweet fragrance.
- Pods: Sweet pea pods are generally short, skinny, furry, and grayish-green. Edible pea pods are longer, broader, and have a smoother, shinier surface.
- Growth Habit: Both edible and ornamental peas can be climbers, but the general appearance differs. Always rely on a combination of features, not just one, for accurate identification.
Comparison of Pea Types
| Feature | Ornamental Sweet Pea (Lathyrus odoratus) | English/Shelling Pea (Pisum sativum) | Snow Pea (Pisum sativum var. saccharatum) |
|---|---|---|---|
| Genus | Lathyrus | Pisum | Pisum |
| Edibility | TOXIC (seeds and plant are poisonous) | Edible peas, inedible pods | Edible pods and peas |
| Pods | Short, skinny, furry, gray-green | Fibrous, inedible pods | Flat, tender, edible pods |
| Stems | Winged, rough, slightly flattened | Round, smooth, succulent | Round, smooth, succulent |
| Flowers | Fragrant, large, varied colors | Modest, typically white or purple | Modest, white |
| Primary Use | Ornamental/Decorative | Food (shelled peas) | Food (whole pod) |
Conclusion
Understanding which peas are not edible is a critical aspect of garden safety, protecting both human family members and household pets. Ornamental sweet peas, while beautiful and fragrant, are toxic and should never be consumed. Furthermore, some inedible pea varieties, like the highly poisonous rosary pea, pose extreme risks and should be handled with great care. Even with common edible peas, such as the English shelling variety, it is important to remember that not every part of the plant is safe to eat. By learning the key visual differences and prioritizing safety, you can confidently enjoy your garden and kitchen without fear of accidental poisoning. When in doubt, it is always safest to discard any questionable plant material. Always purchase seeds from trusted sources that clearly label them as either edible or ornamental.
