Genipa americana L. (Jagua, genipapo)
Nomenclature etc. RUBIACEAE. Einschließlich including. Trade and local names: jagua, caruto.
Description based on: 5 specimens. Tree. Geographic distribution: Mexico and Central America and tropical South America.
General. Heartwood basically brown and white or grey (brownish or greyish brown, sometimes with a pinkish or yellowish hue). Sapwood colour similar to heartwood colour. Basic specific gravity 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. Average number of vessels/mm² 27–33. Average vessel element length 411–729 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5 µm, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits.
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness. Average fibre length 1307–1851 µm. Fibre pits mainly restricted to radial walls, simple to minutely 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 rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells more than 4. 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). Water extract basically colourless to brown or shade of brown. Ethanol extract not fluorescent. Ethanol extract basically colourless to brown or shade of brown.
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).