Caesalpinia velutina (Britt. & Rose) Standl

Caesalpinia velutina is a small, thornless tree up to 10-12 m high and 30 cm diameter at breast height, with a straight upright form, generally light-branched and single-stemmed. Leaves large, bipinnate, with 2-4 pairs of pinnae and one terminal pinna; leaflets large, 5-7 pairs, 3-6 cm long, oblong. Flowers bright yellow arranged on loosely flowered terminal panicles. Pods oblong, 10-15 cm long, indehiscent, mid brown when ripe and occur in distinctive heavy clusters that persist on the tree for many months. The generic name is after A. Caesalpini, 1519-1603, Italian physician and botanist.

C. velutina is believed to be dioecious. Flowering takes place in March-April and the pods remain on the tree until the following dry season (November-February).

Aripin prefers soils with a pH of 5.5 and is mainly found on alfisols and entisols. It is found on calcareous soils, but does not thrive on sites compacted by livestock or prone to water logging.

C. velutina is locally abundant in the dry Motagua Valley of eastern Guatemala although it is generally infrequent in the dry zones of Central America. The tree tolerates up to 8 months dry weather.

Trials have been established in Africa, India and Central America.

The tree is propagated by seed. Seed can be sown directly into pots, seedlings reach 40-50 cm within 15 weeks of germination.

C. velutina can be direct-sown with agricultural crops in agroforestry systems to benefit from crop weeding as this is necessary in the early stages. It is usually planted at a spacing of 1.5-2 m x 1.5-2 m in plantations.

Pests recorded include parasitic plants such as Oryctanthus alveolatus.

There are between 6 000-9 000 seeds/kg. The indehiscent pods need to be manually threshed to extract the seeds. Fresh seed need no pre-sowing treatment, but stored seed should be soaked either in cold water for 24-48 hours or hot water (80 deg C) for 3 minutes. Manual scarification is also effective.

Erosion control: The tree is planted for the protection of watersheds. Shade or shelter: It is suitable for enrichment planting particularly in matorral forests of Mexico, for silvopastoral purposes. Reclamation: Aripin is used for reforestation. Soil improver: The tree provides mulch through its complete leaf loss during the dry season. Ornamental: C. velutina is planted as an ornamental for its bright yellow flowers. Intercropping: It is often intercropped with agricultural crops where soil protection is desired.

Fuel: The tree produces high quality firewood and charcoal. It splits easily and burns slowly with little smoke, dries quickly and stores well. It can also be burnt green in mixture with dry wood. Timber: C. velutina wood is dense, hard and durable. It is used in house construction, tools, agricultural implements, rough furniture and fence posts.