| | CITESwoodID: descriptions, illustrations, identification and information retrieval |
Nomenclature. Family: ZYGOPHYLLACEAE. Other trade relevant species: important trade species: G. officinale, G. sanctum, G. coulteri. Further trade and local names: guajak (CZ, RU, HU); gaiac (FR); guaiacum wood (GB); pockhout (NL); gwajak (PL); guaiac (RO); guayacan (ES, VE); palo santo, guayacancillo (CU, MX); Domingo- Jamaika- Panama Pockholz, Franzosenholz (DE). Code according to DIN EN 13556: GCXX.
CITES(EU) status of protection. Listed in Annex II(B).
Similar timbers. Easily mistaken for Bulnesia arborea (not protected) and B. sarmientoi (CITES II) as well as Chlorocardium rodiei (Greenheart) and Handroanthus spp. (Ipê, Lapacho), both not protected.
Geographic distribution. Mexico and Central America to tropical South America. Guaiacum coulteri: only in Mexico; G. officinale: Caribbean and northern South America (Venezuela, Guyanas); G. sanctum: Caribbean and Central America.
Growth rings, colour, grain, etc. Growth ring boundaries indistinct or absent. Heartwood basically olive to brown (greenish), black to green; occasionally with streaks. Sapwood distinct from heartwood colour. Sapwood mostly very narrow, wood surface oily. Odour distinct (similar to rubber). Wood heavy and hard (1,00–1,30 g/cm3). Surface oily. Interlocked grain present (strongly developed in narrow zones).
Hardwood vs softwood. Vessels (pores) present (= hardwood).
Vessels (pores). Wood diffuse-porous. Vessels (pores) exclusively solitary. Pores (vessels) are hardly visible in the dark heartwood on all surfaces. They can be observed in the early-formed, light coloured sapwood due to the deposition of dark green inclusions. Vessels small, or medium (15–68–80 µm); very few, or few (5–20). Tyloses absent. Other deposits in heartwood vessels (pores) present (greenish black, often already visible in the inner sapwood).
Axial parenchyma. Axial parenchyma present; not banded. Other macroscopically visible types of axial parenchyma: aliform winged (only visible in sapwood).
Rays. Rays narrow; of uniform size. Large rays commonly less than 1 mm high.
Storied structure. Storied structure present. Tiers regular (horizontal or slightly inclined); 8–10 per axial millimetre. Rays, axial parenchyma, vessels (pores) and fibres storied.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour shade of water extract colourless to brown. Ethanol extract fluorescent (weakly purple); colour shade of ethanol extract colourless to brown, or yellow. Splinter burns to charcoal (during combustion conspicuous blisters form on the wood surface).
Additional information. • Transverse sections + wood surface. Transverse section ca. 10x. Tangential surface, natural size. • Comparison Guaiacum spp. vs Gonopterodendron spp.. Guaiacum spp. (Pockholz, Lignum Vitae). Gonopterodendron sarmientoi (Palo santo). Gonopterodendron arborea (Vera). Guaiacum spp. and Gonopterodendron spp. are externally (colour, weight) very similar. However, Gonopterodendron spp. has smaller and much more numerous vessels grouped in radial or diagonal multiples and clusters. Moreover, Gonopterodendron spp. have a less oily wood surface. • Comparison Guaiacum spp. vs Chlorocardium rodiei. Guaiacum spp. (Pockholz, Lignum Vitae). Chlorocardium rodiei (Greenheart). Despite the similar external appearance the timbers of Chlorocardium rodiei and Guaiacum spp. can be easily distinguished. As opposed to Guaiacum spp. the vessels of Chlorocardium rodiei are evenly distributed, larger, filled with tyloses and partially grouped; the wood rays are not storied. • Comparison Guaiacum spp. vs Handroanthus spp.. Guaiacum spp. (Pockholz, Lignum Vitae). Handroanthus spp. (Ipé, Lapacho). As opposed to Guaiacum spp. the vessels of Handroanthus spp. are much more numerous, evenly distributed, partially grouped in radial multiples and often filled with tyloses; the vessels are frequently filled with white or yellow gums.
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., Gembruch, K., and Koch, G. 2014 onwards. CITESwoodID: descriptions, illustrations, identification, and information retrieval. In English, French, German, and Spanish. Version: 4th April 2023. www.delta-intkey.com’.
