It is a perennial tropical tree of Lecythidaceae family, native to Costa Rica, Panama, French Guiana, Tropical South America, growing up to 35 m high and bearing more than 100 flowers at a time.

The tree trunk is up to 0.8m across, appearing more massive due to dense tangle of long dangling branchlets (up to 3m long) that emerge and cover lower trunk, especially in older trees. 

Leaves are smooth to slightly velvety with somewhat serrate margins, simple and arranged spirally at ends of branches. This species is semi-deciduous, shedding its leaves around once to twice a year, usually in response to dry weather.

Flowers are complex nectarless structures, each consisting of 6 large and fleshy-waxy petals that are red to orange on the inside and yellow on the outside forming a hooded structure.

The lower petals have a disk of numerous short and yellow ring-stamens (which produce fertile pollen) , and the hood has a pink-white anemone-like structure of hood-stamens (which produce sterile pollen). Flowers are highly-fragrant, and attract bees, carpenter bees (Xylocopa spp.) are the main pollinators. Other pollinators are bats (which consume the anthers and stamens, besides the sterile pollen). 

Species is cauliflorous -- flowers are produced in racemes along woody extrusions emerging directly from trunk or large branches further up the tree. Flowers last only 1 day, but several are produced at any one time throughout the year.

Fruits are large nuts (20-24cm across), globose, with hard woody exocarp (shell), produced in clusters, taking some 18 months to attain maturity, and resembling rusty-brown cannonballs when ripe. Upper part of fruits crack open upon dropping to the ground, exposing 200-300 hairy seeds embedded in 6-segmented jelly-like pulp that oxidizes from white to bluish-green and emits an unpleasant fermented-like scent when exposed to air.

It is a fuss-free tree. Prefers deep, moist and humus-rich soils. Provide regular water. Propagate by seeds from ripe fruits (although germination may be difficult), or woody stem cuttings. Handle with care, as flower pollen and fruit pulp may be allergenic or irritating to susceptible individuals.

Hard shells of fruits used to make containers and utensils. Fragrant flowers used to scent perfumes and cosmetics. Soft, light-colored wood utilized to make furniture. 

*In India this flower is called Nagkeshar. Commonly planted near Hindu temples, regarded as sacred by Hindus because flowers resemble the Naga (hooded snake) of Lord Shiva. Flowers used in Hindu prayer, also used by Buddhist worshippers in Sri Lanka. 

Fruit pulp reportedly eaten by Amazonian Shamans, but usually avoided by others due to bad odour and stinging after-effects.

 Medicinal uses : Extracts from tree’s tissues have antiseptic and antifungal properties, used by Amazonian Shamans to treat malaria. Young leaves used medicinally to relieve toothache, leaf juice used to treat skin diseases, fruit pulp used to disinfect wounds.

Reference 

Plants of Singapore