About Lathyrus oleraceus Lam.
Lathyrus oleraceus Lam. (the pea) is a pod-shaped vegetable that is most commonly green, occasionally golden yellow, and infrequently purple. It is widely grown as a cool-season crop. Seeds can be planted as soon as soil temperature reaches 10 °C (50 °F), and plants grow best at temperatures between 13 to 18 °C (55 to 64 °F). They do not grow well in the summer heat of warmer temperate and lowland tropical climates, but thrive in cooler, high-elevation tropical areas. Many cultivars reach maturity around 60 days after planting. There are both low-growing and vining pea cultivars. Vining cultivars grow thin tendrils from their leaves that coil around any available support, and can climb to 1 to 2 metres (3 to 7 ft) high. A traditional method to support climbing peas is to push upright branches pruned from trees or other woody plants into the soil, creating a lattice for peas to climb; these branches are called pea sticks, or sometimes pea brush. Metal fences, twine, or netting supported by a frame can also be used for the same purpose. In dense plantings, pea plants provide a degree of mutual support to one another. Pea plants are capable of self-pollination. Wild pea is restricted to the Mediterranean Basin and the Near East. The earliest archaeological finds of peas come from the late Neolithic era in what is now Syria, Anatolia, Palestine, Iraq, Jordan and Greece. In Egypt, early finds date to around 4800–4400 BC in the Nile Delta area, and to around 3800–3600 BC in Upper Egypt. In northern Europe, specifically Fennoscandia, pea findings date back to 4000 BC. Peas were already present in Georgia by the 5th millennium BC. Archaeological finds of peas from farther east date to more recent periods: peas were present in Afghanistan around 2000 BC, and in the Harappan civilization of modern-day Pakistan and western and northwestern India between 2250–1750 BC. In the second half of the 2nd millennium BC, this legume crop appears in the Ganges Basin and southern India. Some people experience allergic reactions to peas, with vicilin or convicilin being the most common allergens. Some pea cultivars do not have the tough membrane inside the pod wall, and instead have tender edible pods that allow the whole pod to be eaten. There are two main types of these edible-pod peas. Snow peas have flat pods with thin pod walls, and both their pods and seeds are eaten when they are very young. Snap peas, also called sugar snap peas, have rounded pods with thick pod walls, and both their pods and seeds are eaten before the plant reaches maturity. The name sugar pea can refer to both types, or can be used as a synonym for either snow peas or snap peas depending on the dictionary. The term mangetout, from the French pois mange-tout meaning 'eat-all pea', is generally used in British English to refer specifically to snow peas, but may also refer to snap peas, particularly in other contexts. Both snow peas and snap peas belong to the Macrocarpon Group, a cultivar group based on the variety Pisum sativum var. macrocarpum Ser., which was named in 1825. The original 1825 publication described this variety as having very compressed, non-leathery edible pods.
