Lathyrus sativus L.

First published in Sp. Pl.: 730 (1753)
This species is accepted
The native range of this species is a cultigen from Balkan Peninsula. It is a climbing annual and grows primarily in the temperate biome. It is has environmental uses, as animal food, a poison and a medicine and for food.


Biogeografic region: Andean. Colombian departments: Bogotá DC.
Habitat according IUCN Habitats Classification: artificial - terrestrial.

Kew Species Profiles

General Description

Lathyrus sativus is a crop that is considered to be both a saviour and a destroyer. In times of famine, it is often the only alternative to starvation. It can withstand extreme environments, from drought to flooding.

The crop is harmless to humans in small quantities, but eating it as a major part of the diet over a three month period can cause permanent paralysis below the knees in adults and brain damage in children, a disorder known as lathyrism. The culprit is a potent neurotoxin called ODAP (β-N-Oxalyl-L-α,β-diaminopropionic acid) which is responsible for the drought and waterlogging tolerance of grass pea but, if taken in large enough quantities, brings on the neurological disorder.

Grass pea is easy to cultivate, and is tasty and high in nutritious protein, making it a popular crop in south west Asia and the eastern Horn of Africa where it is also grown to feed livestock. As in many members of the legume family (Leguminosae), grasspea is able to fix nitrogen from the air through a symbiotic relationship with bacteria housed in root nodules, which means that growing it keeps the soil healthy and well fertilised.

Species Profile
Geography and distribution

The origins of Lathyrus sativus are unclear. Archaeological evidence suggests that domestication of grass pea probably occurred in the Balkan region around 6,000 BC, and further remains have been found in India dating to 2,000-1,500 BC. Today, grass pea is widely cultivated in Asia, (especially in Bangladesh, India, Nepal, Pakistan and the Middle East), southern Europe and North Africa and to a lesser degree America, Australia and South Africa.

The crop can be grown on a wide range of soil types, including nutrient poor soils and heavy clays and can tolerate waterlogging and moderate salinity. 


Overview: Lathyrus sativus is a much-branched annual herb up to 170 cm tall with a well developed taproot. 

Leaves: The stem is slender, quadrangular and winged with leaves arranged alternately along it. Each leaf is composed of 1-4 leaflets and ends in a simple or branched tendril. Stipules (appendages at the base of the leaf) are narrowly triangular, prominent and leaf-like. The petiole (the part which connects the leaf to the stem) is usually winged and is up to 3.5 cm long. 

Flowers: Blue, reddish-purple, red, pink or white and papilionaceous, typical of species belonging to the Leguminosae subfamily Papilionoideae, and resemble, for example, the common garden pea ( Pisum sativum ) flower. Each flower has 10 stamens, 9 of which are fused into a partial tube, with the tenth stamen free. The ovary is positioned above the sepals, petals and stamens.  The style is abruptly upturned and the stigma is spoon-shaped. 

Fruit: An oblong, laterally flattened pod up to 5.5 x 2 cm and contains up to 7 seeds. The seeds are wedge-shaped, 4-7 mm in diameter and can be white, pale green, grey or brown, and sometimes have a marbled pattern.  


Grass pea is cultivated mainly for its edible seeds which are typically consumed in the form of sauces and soups: 

In Ethiopia and Eritrea, the pulse can be eaten after boiling or is ground and made into unleavened bread, known as 'kitta' which is consumed mainly during times of famine.In India, grass pea seeds are most commonly eaten as a 'dahl', they can also be made into paste balls, put in curry or boiled and eaten as a pulse.Flour, made by grinding the seeds is used to make 'roti' which is a staple food for landless labourers in Bangladesh.In India it is not an unusual practice to use grass pea to adulterate more expensive pulses such as chickpea or pigeon pea.

Care should be taken since consumption of grass pea beyond a certain threshold can cause paralysis of the lower limbs in people and animals, a disorder known as lathyrism.

The seeds are also frequently used as an ingredient in animal feed. In many Asian countries, the immature pods of the plant are cooked and eaten as a vegetable. It is also common to dry and store the young vegetative parts of grass pea so that they can be eaten outside of the growing season.

The high protein content and reliable yield of grass pea makes the crop excellent fodder for cattle and can be eaten green or as hay. Like many other legumes, grass pea is able to fix nitrogen from the air which means that the crop is valued as green manure, for example in Australia and Canada.

Grass pea also has medicinal uses, for example, the oil from the seeds is a powerful cathartic (stimulating bowel evacuation).

Crop wild relatives of grass pea

The wild relatives of grass pea are an important source of genetic diversity for the cultivation of low toxin varieties. Grass pea is one of the 29 priority crops that are the focus of the Adapting Agriculture to Climate Change project led by Kew's Millennium Seed Bank and the Global Crop Diversity Trust. By collecting the wild relatives of crops such as grass pea and making their seeds available to breeders, useful traits such as lower toxicity levels, in the case of grass pea, and resistance to pests, diseases and environmental stresses can be passed on to crops, making them more resilient and better equipped to deal with climate change. 

The development of low toxin varieties of grass pea is a matter of food security and is something that will have a direct impact on the health and livelihood of thousands of people. Grass pea takes on a special importance in the light of climate change since tolerance to drought and flooding are characteristics that give the crop an advantage in stressful conditions.

Millennium Seed Bank: Seed storage

The  Millennium Seed Bank Partnership aims to save plants worldwide, focusing on those plants which are under threat and those which are of most use in the future. Once seeds have been collected they are dried, packaged and stored at -20°C in our seed bank vault.

Description of seeds: Average weight of 1,000 seeds = 98.5 g

Number of seed collections stored in the Millennium Seed Bank: One

Seed storage behaviour: Orthodox (the seeds of this plant can be dried to a low moisture content without significantly reducing their viability. This means they are suitable for long-term frozen storage)

Germination testing: Successful

This species at Kew

Pressed and dried specimens of grass pea are held in Kew's Herbarium, where they are available to researchers by appointment. Details and images, of some of these specimens can be seen online in Kew's Herbarium Catalogue.

India, Nepal
Grasspea grows well in areas with an average annual rainfall of 400-650 mm/year and an average temperature of 10-25°C.
Widespread in cultivation.

The crop is harmless to humans in small quantities. However, eating it as a major part of the diet over an extended period can cause permanent paralysis below the knees in adults and brain damage in children, a disorder known as lathyrism.


International Legume Database and Information Service

Cultigen not known in the wild
Africa: Cultivated
Morphology General Habit
Annual, Climbing, Herb
Akervial, Almorta, Assar, Blue Vetchling, Burchak, Chicharo, Chickling Pea, Chickling Vetch, China Aziatskaya, China Posevnaya, Chyna Pasyaounaya, Cicerchia, Dholl Kessari, Ekin Kululche, Gesse Blanche, Gesse Cultivee, Grass Pea, Grass Peavine, Grasspea,

IUCN Red List of Threatened Species

LC - least concern


Use Animal Food
Used as animal food.
Use Environmental
Environmental uses.
Use Gene Sources
Used as gene sources.
Use Food
Used for food.
Use Medicines
Medical uses.
Use Poisons

Food, fodder, hay, green manure, medicinal.

Chemical products, Environmental, Food and Drink, Forage, Medicine, Toxins, Weed

Common Names

Grass pea


  • Herbarium Catalogue Specimens

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  • IUCN Categories

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  • International Legume Database and Information Service

    • International Legume Database and Information Service (ILDIS) V10.39 Nov 2011
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at and
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  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at and
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants.
  • Kew Science Photographs

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  • Kew Species Profiles

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  • Useful Plants and Fungi of Colombia