In Family Caesalpiniaceae, Plants of the World Online (Kew) accepts 22 species.
Many are native to the tropical and subtropical areas of South America especially Venezuela.
They are shrubs or trees with a wide fibrous root system.
New branches may have dense hairs and 4 longitudinal grooves, older ones are smooth and round.
Large evergreen or deciduous leaves are alternately arranged.
The petioles may be very short and they have a swollen base.
The small to large leaf-like stipules between the petiole bases are deciduous.
The pinnate leaves are often in clusters of up to ten.
They have few to many opposite or sub-opposite leaflets.
Leaflets are on a short stalk (petiolule) with no stipels at the base.
The midrib ends with a pair of leaflets (a paripinnate leaf).
Elliptic, ovate, obovate or lance-shaped leaflets have a long thin tip.
Drooping new leaflets are often coloured or spotted.
Hairs on young leaves are lost on mature ones.
Axillary inflorescences are a terminal or cauliflorous (on old wood) raceme.
Racemes have flowers, on a pedicel, along a midrib with the lower flowers opening first.
Often the nodes are very close so the racemes are condensed into a roughly spherical head (capilitum).
The erect to drooping inflorescences have whorls of stiff bracts forming an involucre at the base.
The spirally arrange bracts have mostly fallen by the time the flowers are mature.
Flowers have a short or very short hairy stalk (pedicel).
At the base are large coloured bracteoles (bractlets).
The bracteole bases are fused into a tube with 2 long lobes.
They surround the buds then remain at the base of the open flowers.
Their outer surface has dense hairs.
Flowers have a hypanthium which is a tube formed by fusion of the sepal, petal and stamen bases.
Up to around 5 cm long there are nectar secreting cells in its smooth inner wall.
On the rim are 5 sepals but the upper 2 are fused making it look like 4.
The petal-like sepals are unequal being oblong to spatula-shaped.
The (4) 5 overlapping petals all have a narrow claw base with an obovate lobe.
The bases of the (10) 11 (12) stamen filaments are fused into a tube with dense hairs on the inner surface.
The free unequal ends of the filaments have oblong dorsifixed anthers.
The anthers, opening through longitudinal slits may lie within or past the petals.
The hairy superior ovary has a single locule with 1 to 4 (8) ovules.
It is on a stalk (stipe or gynophore) that lies inside the hypanthium and is fused to one side of it.
The long curved style has a small spherical stigma with papillae on it.
The fruit are an oblong legume (pod) up to 40 cm long densely covered with hairs.
On a short stalk it is straight or curved and compressed sideways.
Pods open along both of the thickened sutures and the 2 halves roll up or twist.
The variously shaped seeds are up to 5 cm long.
J.F.
