Earthnut Pea, Tuberous sweetpea

Lathyrus tuberosus

Physical Characteristics

Lathyrus tuberosus is a PERENNIAL growing to 1.2 m (4ft). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower from June to July, and the seeds ripen in August. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Europe to W. Asia. Naturalized in Britain in a very few sites in E. England.

Habitats

Woodland Garden Sunny Edge; Dappled Shade; Hedgerow;

Edible Uses

Edible Parts: Root Edible Uses: Root - cooked or raw[2, 27, 46, 61, 105]. Sweet and starchy, it is delicious when baked with a flavour that is somewhat like a sweet potato[183, K]. Taste trials consistently place this root very highly, it is certainly one of our favourites[K]. Unfortunately, yields are rather low and so the plant is only worthwhile growing as a taste treat, not as a staple crop[K].

Medicinal Uses

None known

Known Hazards

Although no records of toxicity have been found for this plant, the seed of some species in this genus contain a toxic amino acid that can cause a severe disease of the nervous system known as 'lathyrism' if they are eaten in large amounts (although small quantities are said to be nutritious)[65, 76]. Great caution is advised.