Parkia speciosa

The petai tree can grow to about 90 feet (30 metres). It bears flowers in a light-bulb shaped mass at the end of long stalks. The flowers secrete a nectar that attracts bats and other pollinators. The tiny flowers mature and die. Long, twisted, translucent pods emerge in a cluster of 7 or 8 pods. When those pods are mature, within them will reside the petai beans or seeds.

Scientific Classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fabales
Family:	Fabaceae
Subfamily:	Mimosoideae
Genus:	Parkia
Species:	P. speciosa

Parkia speciosa (petai, twisted cluster bean, yongchaak or stink bean), is a plant of the genus Parkia in the family Fabaceae. It bears long, flat edible beans with bright green seeds the size and shape of plump almonds which have a rather peculiar smell, characterised by some as being similar to that added to methane gas.

They are an acquired taste, but are popular in southern Thailand, Burma, Malaysia, Indonesia and North-eastern India and are sold in bunches, still in the pod, or the seeds are sold in plastic bags. They are exported in jars or cans, pickled in brine.

Depending on the country of origin they may be labelled peteh, petai, yongchaak or sataw (sometimes spelled sator). They are best when combined with other strong flavoured foods such as garlic, chile peppers, and dried shrimp, as in "sambal petai" or added to a Thai curry such as Thai Green Curry of Duck. When young the pods are flat because the seeds have not yet developed, and they hang like a bunch of slightly twisted ribbons, pale green, almost translucent. At this stage they may be eaten raw, fried or pickled. Young tender pods with undeveloped beans can be used whole in stir fried dishes. In North-eastern India, the seeds are dried and seasoned for later consumption. When dried the seeds turn black.

Petai beans or seeds look like broad beans. Petai has earned its nickname 'stink bean' because its strong smell is very pervasive. Like mature broad beans, they may have to be peeled before cooking. It lingers in the mouth and body. Like asparagus, it contains certain amino acids that give a strong smell to ones urine, an effect that can be noticed up to two days after consumption. And like other beans, their complex carbohydrates can also cause strong-smelling flatulence.