Cassia parahyba Vell.

Schizolobium parahybum is unarmed, with a cylindrical bole, high buttresses and a wide spreading, open crown. Leaves bipinnate, large; pinnae 15-20 pairs, fernlike; leaflets small, elliptic, 10-20 pairs, stipules absent. Flowers golden yellow, large, profusely produced in axillary semi-erect racemes or terminal panicles; bracts minute; bracteoles absent; calyx tube obliquely turbinate; lobes 5, overlapping, reflexed at flowering; petals 5, clawed, subequal, overlapping, uppermost petal innermost; stamens 10, free, subdeclinate; filaments villous, basally rough; anthers uniform, longitudinally dehiscent; ovary subsessile affixed to 1 side of calyx tube, many-ovuled, style filiform; stigma minute, terminal. Pod flat, spoon or tear-drop shaped, exocarp firm, leathery, tardily dehiscent. Seed large, oblong, compressed, located near apex. The genus Schizolobium has 4-5 members. The generic name is derived from the Greek verb schizo, “divide” and lobion, “pod”; the inner and outer layers of the pod separate at maturity, whereas the specific epithet is after the Parahyba River in Brazil.

S. parahybum is hermaphroditic flowering when leafless.

Flourishes on well-drained soils.

S. parahybum is a widespread pioneer species from tropical and premontane forests zones of the American Atlantic coast, flourishing on well-drained moist soils on plains or hillsides.

Guapuruvu is a magnificent, fast growing ornamental tree which has been introduced into cultivation worldwide.

The plant can be easily propagated from seed. Propagation by cuttings is moderately easy and requires treatment with Naphtyl-Acetic Acid.

Guapuruvu is fast growing, three year old plants are often 7-8 m tall; forest specimens reach heights of 30-35 m. Water-stress relating to altered watering regimes seems to little affect growth, or readiness for transplantation in nursery seedlings. In one study nursery seedlings watered at intervals (up to 8 days) were ready for transplanting sooner.

Wood attacked by insects.

Seeds usually need mechanical scarification or thermal shock to ensure germination within 5-15 days. The hard, impermeable seed coat promotes dormancy. Breaking of dormancy is by removal of the seed tip, immersion in boiling water, mechanical scarification, chemical (acid, organic solvent), scarification or brief exposure to fire. Immersion in boiling water is the most effective treatment, in terms of both speed of germination and percentage germination, economy and practicality; after 28 days 92% germination was observed in water immersed seeds. There are 500 seeds/kg.

Erosion control: The tree protects surrounding soil from soil erosion. Shade or shelter: Guapuruvu is an important shade tree. Nitrogen fixing: No reports of nodulation are given for guapuruvu. Soil improver: The enormous amount of biomass shed by the tree improves soil fertility. Ornamental: A spectacular fast-growing tree popularly cultivated as an ornamental, especially beautiful in flower with masses of yellow gold blossoms. Intercropping: The Brazilian fern tree is a promising agroforestry species, intercropping is possible because of its light shade.

Food: A number of amino acids are found in the seeds, however, a seed chymotrypsin inhibitor is also reported. Fuel: The tree can provide fuelwood. Timber: Wood with a low specific gravity of 0.28-0.35 g/cu cm The timber is rarely utilized, possibly because of its repulsive smell when fresh. Wood not durable and resistant to insect attack. Quamwood is a potential source of paper pulp and plywood. Other products: Methyl methacrylate (a plastic monomer) and S. parahybum wood are used in manufacture of wood-plastic composites.