Common Name: Yellow-Flowered Pea
Lathyrus aphaca is an annual plant growing from a thin rootstock; it produces one to a few erect stems that often cling to surrounding vegetation by means of tendrils, the plant growing 15 - 60cm tall[
The plant is harvested from the wild for local use as a food, medicine and dyestuff.
All parts of the plant, but especially the seed, contain a toxic amino-acid. It is produced in the plant at about the same time that the seed starts to develop. In small quantities the amino acid is innocuous, and the seeds of several Lathyrus species are eaten as a nutritious part of the diet. However, in larger quantities (the seed should form less than 30% of a balanced diet), it can cause a very serious disease of the nervous system known as 'lathyrism'. Symptoms appear as a paralysis of the muscles below the knees, pains in the back, followed by weakness and stiffness of the legs and progressive locomotive incoordination[
Eurasia - Britain to Spain, through Ukraine to C. Asia, through Turkey & Levant to Afghanistan & Himalayas; Africa - Macaronesia, Morocco to Egypt
Dry places on sand, gravel and chalk[
]. Found mainly as a weed among crops and in gardens, rarely among shrubs and on herbaceous slopes; at elevations up to 1,800 metres[
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An easily grown plant, succeeding in any moderately good garden soil but preferring a position in full sun[
]. Plants dislike shade.
An interesting plant botanically because the true leaves have been modified into tendrils and the stipules have become leaves[
Plants climb by means of tendrils[
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[
]. When removing plant remains at the end of the growing season, it is best to only remove the aerial parts of the plant, leaving the roots in the ground to decay and release their nitrogen.
Seed - cooked. Only use when immature, the fully ripe seed can be narcotic in large quantities[
]. The seed is harmless and nutritious when eaten in small quantities[
]. Some caution is advised, see the notes above on toxicity.
The seed contains around 23.5% crude protein, 15.2% fats and 34.6% carbohydrates.
The brown seedpods are around 35mm long and 8mm wide, containing 6 - 8 small seeds[
The ripe seeds are said to be antibacterial, narcotic[
]. They are used in the treatment of toothache[
The flowers are resolvent[
The plant is known to contain flavonoids, tannins, glycosides, alkaloids and terpenoids[
A black dye is obtained from the plant when iron is used as the mordant[
Pre-soak the seed for 24 hours in warm water and then sow in early spring in a cold frame[
]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer.
If you have sufficient seed, then it can also be sown in situ in mid spring[
]. In nature, most of the seed germinates in the autumn but many of the seedlings do not manage to survive the winter[