Commercial Timbers


H. G. Richter and M. J. Dallwitz

Genipa americana L. (Jagua, genipapo)

Nomenclature etc. RUBIACEAE. Including Genipa caruto H.B.K. Trade and local names: jagua, caruto (cAm, sAm). Not protected under CITES regulations.

Description based on 5 specimens. Tree. Geographic distribution: Mexico and Central America, or Caribbean, or tropical South America.

General. Heartwood basically brown and white or grey (brownish or greyish brown, sometimes with a pinkish or yellowish hue), without streaks. Sapwood colour similar to heartwood colour. Density 0.6–0.75 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in diagonal and/or radial pattern, exclusively solitary. Average tangential vessel diameter 47–81 µm; diameter of vessel lumina: medium. Average number of vessels/mm² 27–33. Average vessel element length 410–730 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5 µm, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses in vessels absent.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness. Average fibre length 1310–1850 µm. Fibre pits common in both radial and tangential walls, distinctly bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 5–8.

Rays. Rays 10–15 per tangential mm, multiseriate (also if only few), 2–3 cells wide. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, with more than 4 marginal rows of upright or square cells. Disjunctive ray parenchyma end walls distinct, or indistinct or absent.

Mineral inclusions. Crystals present or not observed, prismatic, located in ray cells. Crystal-containing ray cells procumbent. Number of crystals per cell or chamber more than one. Crystals in one cell or chamber of two distinct sizes (conglomeration of small crystals, seemingly druses). Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (very light blue); basically colourless to brown or shade of brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown.

Illustrations. • Transverse section. Genipa americana. • Tangential section. Genipa americana. • Radial section. Genipa americana. • Miscellaneous. Genipa americana. Note occasional presence of micro crystals in ray cells (left) and vasicentric tracheids (right).

The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009.’.