| # CITES wood ID: descriptions, illustrations, identification, and information retrieval |

H.G. Richter, K. Gembruch, G. Koch

## Dalbergia spp.

All species of this genus (worldwide) are subject to protection under CITES Annex II#15, with the exception of Dalbergia nigra listed under Annex I since 1992. The following footnote (#15) which describes the scope of the listing including the parts and products excluded from protection (see below) has come into effect January 02, 2017:

### 1. Comments on CITES II regulations

#### Footnote #15

All parts and derivatives are included, except:

a) Leaves, flowers, pollen, fruits, and seeds.

b) Finished products up to a maximum weight of 10 kg wood of protected wood species per consignment.

Comment: With the exception of D. cochinchinensis (see under (c)), non-commercial products weighing up to 10 kg, which are not covered by footnote 15 b), do not require export or import permits. Personal or household items, heirlooms and antiques may be subject to exceptions to the CITES rules. More detailed information can be given by the CITES authorities responsible for species conservation.

c) Finished musical instruments, finished musical instrument parts and ready-made musical instrument accessories

d) Parts and derivatives of Dalbergia cochinchinensis, which are covered by Annotation #4.

Comment: All parts, products and further processed products are subject to the provisions; exception (b) does not apply to the species Dalbergia cochinchinensis. Consequently, for Dalbergia cochinchinensis the trade with all parts and derivatives of a maximum total weight of 10 kg per shipment does require an export permit* as stipulated under CITES II regulations. For countries outside the European Union an import permit is NOT required. As regards member countries of the European Union, all imports of D. cochinchinensis require an import permit in addition to the export permit.

___________________________

*this also applies to re-exports!

e) Parts and derivatives of Dalbergia spp. originating and exported from Mexico, which are covered by Annotation #6.

Comment: The export of finished products made in Mexico manufactured from wood of the species listed below do NOT require the export / import permits stipulated under CITES Annex II. Consequently, concerning the origin Mexico only logs, sawn wood, veneer sheets and plywood are protected.

The following species belong to the Mexican population: Dalbergia brownei, Dalbergia calderonii, Dalbergia calycina, Dalbergia congestiflora, Dalbergia cubilquitzensis, Dalbergia glomerata, Dalbergia granadillo, Dalbergia longepedunculata, Dalbergia luteola, Dalbergia melanocardium, Dalbergia modesta, Dalbergia palo-escrito, Dalbergia retusa (doubtful), Dalbergia rhachiflexa, Dalbergia ruddae, Dalbergia tucurensis, Dalbergia stevensonii (only the species printed in bold letters are of commercial importance and considered in this database).

Attention: For wood of Dalbergia spp. originating from countries other than Mexico, the exemption listed under e) does not apply.

For information footnotes #4 and #6 are reproduced as follows:

#### Footnote #4

All parts and derivatives, except:

a) Seeds (including seedpods of Orchidaceae), spores and pollen (including pollinia). The exemption does not apply to seeds from Cactaceae spp. exported from Mexico, and to seeds from Beccariophoenix madagascariensis and Dypsis decaryi exported from Madagascar.

b) Seedling or tissue cultures obtained in vitro, in solid or liquid media, transported in sterile containers.

c) Cut flowers of artificially propagated plants.

d) Fruits, and parts and derivatives thereof, of naturalized or artificially propagated plants of the genus Vanilla (Orchidaceae) and of the family Cactaceae.

e) Stems, flowers, and parts and derivatives thereof, of naturalized or artificially propagated plants of the genera Opuntia subgenus Opuntia and Selenicereus (Cactaceae).

f) Finished products of Euphorbia antisyphilitica packaged and ready for retail trade.

#### Footnote #6

Logs or squares, sawn wood, veneer sheets and plywood.

### 2. Dalbergia species in the database

The genus Dalbergia comprises nearly 280 species worldwide, largely climbers, shrubs or small trees which are not used commercially as a source for timber. For inclusion in the database a limited number of species were selected with a proven record of being utilized and traded in national and international markets. Commercially important Dalbergia timbers come from South and Southeast Asia, Africa including Madagascar, Central America and South America. Similar species which cannot be easily distinguished macroscopically are combined in groups.

#### South and Southeast Asia:

- Dalbergia bariensis (Myanmar, Indochina)
- Dalbergia cochinchinensis and similar species (Myanmar, Indochina),
- Dalbergia latifolia (India, Indonesia, Nepal, Pakistan)
- Dalbergia odorifera (China)
- Dalbergia oliveri (Laos, Myanmar, Thailand, Vietnam)
- Dalbergia sissoo (Afghanistan; Bangladesh; Bhutan; India; Iran, Myanmar; Nepal; Pakistan)

#### Africa and Madagascar

- Dalbergia baronii (Madagascar)
- Dalbergia greveana and similar species (Madagascar)
- Dalbergia louvelii, D. maritima (Madagascar)
- Dalbergia madagascariensis (Madagascar)
- Dalbergia melanoxylon (sub-Saharan Africa)

#### South America

- Dalbergia cearensis (northeast Brazil)
- Dalbergia decipularis (northeast Brazil)
- Dalbergia nigra (eastern Brazil)
- Dalbergia spruceana (Amazon Basin of Bolivia, Brazil, Venezuela)

#### Central America

- Dalbergia congestiflora (western Mexiko)
- Dalbergia cubilquitzensis, D. tucurensis (southwestern Mexiko, Central America)
- Dalbergia palo-escrito (Mexiko)
- Dalbergia retusa, D. granadillo (Honduras to Panama, western Mexiko)
- Dalbergia stevensonii (Belize, southwestern Mexiko, Guatemala)

### 3. Wood structure and identification

The following deliberations are largely restricted to macroscopic features that are recognizable on the processed wood without resorting to destructive testing. Features that require destructive methods, for instance physico-chemical properties or density, are not considered in this context.

Macroscopically recognizable features which all Dalbergia species have in common:

1. hardwoods with vessels which can be observed as "pores" on transverse sections (Figure 1),

2. storied arrangement of rays, best observed with a hand lens (10x) on tangential surfaces (Figure 2),

3. presence of banded axial parenchyma (Figures 4, 5, 6, 7). All species have narrow marginal bands delimiting the growth increments, which in very dark woods can be seen only in the lighter coloured sapwood (D. melanoxylon, D. retusa); many species also form more or less apparent parenchyma bands between the growth increment boundaries (Figure 6),

4. vessels/pores solitary mixed with radial multiples of 2-3, more rarely of 4 or more pores (Figures 1, 4, 5, 6, 7).

Quantitative features that allow further differentiation can only be determined to a very limited extent on the processed wood, for example, with guitars (eddies, fingerboard, bridge, body) or strings (eddy, fingerboard, chinrest). But it is possible primarily with the number of stories of rays per axial mm by means of a magnifying glass with a built-in metric scale or simple one using a scaled transparency:

5. rays in Dalbergia species are very low, usually around 200 µm in height, and commonly form 5 to 6 stories per axial mm.

Figure 1. Dalbergia nigra (left) with a diffuse-porous and D. decipularis (right) with a semi-ring-porous distribution pattern

Figure 2. Storied arrangement of rays on tangential surface: natural size (left) and slightly enlarged (right)

This combination of features is common to all Dalbergia species integrated into the database, as well as to some other taxa, among them those of the closely related genus Pterocarpus.

Other features which all Dalbergia species have in common but which can only recorded under appropriate circumstances and therefore cannot usually be used when identifying processed wood, are:

- in spite of considerable fluctuations within the genus Dalbergia, all species listed here fall into the category of "heavy and hard" woods (the density cannot be determined by non-destructive methods);
- most of the commercially available Dalbergia woods have a more or less pronounced interlocked grain;
- the colour of the sapwood is markedly distinct from that of the heartwood (a feature that can only be used when sapwood and heartwood are present).

Within the Dalbergia species considered, the colour of the heartwood can be a useful feature for the determination. However, caution is required for several reasons. On the one hand, the assessment of a colour tone is distinctly subjective and can vary from person to person. On the other hand, the colour can change with time due to the influence of oxygen and UV radiation; some woods become pale, others darken, and again with others a complete colour change takes place, as in some Moraceae, whose heartwood in the fresh state is a shiny yellow, but in the aged dry state is deep brown. Finally, there is also the possibility that wood has been treated with pigmented finishes (stains, lacquers, varnishes). This is often the case with furniture made in Pakistan and India from "shisham" (Dalbergia sissoo) which is given a uniform dark colour coat because of the high percentage of light coloured sapwood used in the manufacture of such items (Figure 3). The colour of a wood surface should therefore always be assessed on dry, recently processed material, untreated or treated with transparent finishes.

Figure 3. Seat of a chair (detail): on the left the top with the original finish, on the right the corresponding section of the bottom after sanding with portions of sapwood of the lower board

Some Dalbergia woods have a distinct brownish-violet colour. If only "violet" is selected from the given options of colours ("brown" is coded for almost all species), the number of possible matches is reduced to some species or species groups of this genus and few closely related timbers of the same family as, for instance, the genera Pterocarpus and Platymiscium. The choice of other colours such as "red", "black" or "yellow" produces a similar result, but with a different species composition.

The pore distribution pattern on the transverse (cross) section is a further feature for distinguishing species within the genus Dalbergia. Species growing under humid climate conditions have wood with a diffuse-porous distribution pattern and commonly few and large vessels (Figure 1, left); others which grow in a pronounced dry climate (north-eastern Brazil, western Madagascar) generally form wood with a semi-ring-porous distribution pattern and medium-sized, rarely small, vessels in the latewood (Figure 1, right). However, the use of this feature requires that a sufficiently large transverse section of the piece to be examined is accessible to the observation with the magnifying glass.

- wood diffuse-porous; or
- wood semi-ring-porous.

Using either one of these options of pore distribution patterns, there is little change in the composition of the remaining species, which have either one or the other in common. And again, most belong to the genera Dalbergia and Pterocarpus.

When identifying an unknown wood one should never rely exclusively on external appearance (colour, figure). Such a similarity is evident between individual Dalbergia species and other woods, so-called "look alikes". This holds particularly true for the species Dalbergia nigra (Brazilian rosewood) and Machaerium scleroxylon (morado), and also for Dalbergia spruceana (Amazon rosewood) when compared with Platymiscium yucatanum (granadillo). However, the direct comparison of the respective transverse sections shows the clear structural differences, so that a distinction is possible (Figures 4 and 5, respectively).

Figure 4. Tangential surface and transverse section of Dalbergia nigra (left column) and of Machaerium scleroxylon (right column)

Figure 5. Tangential surface and transverse section of Dalbergia spruceana (left column) and Platymiscium yucatanum (right column)

The most variable tissue in Dalbergia woods is the axial parenchyma. Marginal bands occur in all the species described here although they cannot be detected reliably in some individual cases, for example in Dalbergia retusa (cocobolo), and also in most of similar species belonging to other genera. In addition, some species have a macroscopically well recognizable, lavishly developed banded parenchyma (Figure 6), often resulting from the confluence of aliform parenchyma and therefore usually wavy. Such bands, commonly much wider than the rays, are found in most species growing on the Indian subcontinent (for example Dalbergia sissoo, D. oliveri) and in Indochina (for example Dalbergia bariensis, D. cochinchinensis, among others), as well as in species from eastern Madagascar (for example D. baronii, D. louvelii, D. madagascariensis, among others). In the commercially important species from South America, such a strongly developed banded parenchyma is absent, and in some Central American species (for example Dalbergia congestiflora, D. cubilquitzensis) axial parenchyma bands are also present but less numerous and at irregular intervals. Most species of the closely related genus Pterocarpus (Figure 6) also possess such a lavishly developed banded parenchyma. Regardless of whether one works only with macroscopic or, additionally, with microscopic features, many woods of the genus Dalbergia show consistently good agreement with those of the genus Pterocarpus, and thus there is considerable danger of mistaking one for the other leading to a possibly wrong determination.

On the other hand, the predominantly semi-ring-porous Dalbergia species such as D. decipularis (Figure 1, right), D. greveana (and similar species), and D. melanoxylon (Figure 7) feature more or less regular, narrow and less conspicuous parenchyma bands. In smaller numbers and at irregular intervals, they can also be observed in many diffuse-porous species, for example D. spruceana (Figure 5) and D. stevensonii.

Figure 6. Numerous and wide axial parenchyma bands in Dalbergia madagascariensis (left) and Pterocarpus macrocarpus (right).

In a third group of Dalbergia species, a well-defined banded parenchyma is usually not recognizable, as for example in Dalbergia nigra (Figure 1) and D. retusa + D. granadillo (Figure 7).

Figure 7. Narrow axial parenchyma bands, usually formed in the latewood and only visible in the light-coloured sapwood of Dalbergia melanoxylon (left); a well developed banded axial parenchyma appears absent at the macroscopic level in D. retusa (right), except marginal bands

### 4. Can individual Dalbergia species be identified macroscopically?

Only in a few cases is this possible and also on the supposition that certain conditions are met, for example:

- access to a sufficiently large area of the transverse section,
- the possibility to determine the number of tiers formed by the storied rays,
- a wood surface which is as unadulterated as possible

With the available features and their variants, this is well possible at least for the following Dalbergia species:

1. Dalbergia decipularis (Brazilian tulipwood)

1. vessels/pores present

2. storied structure present

3. number of tiers per axial mm: 5-6

4. heartwood with streaks

5. heartwood colour red+yellow

6. wood semi-ring-porous

7. earlywood pore ring uniseriate

2. Dalbergia melanoxylon (African blackwood)

1. vessels/pores present

2. storied structure present

3. number of tiers per axial mm: 5-6

4. wood semi-ring-porous

5. heartwood colour black

Other combinations of features lead in the best case to two, but usually to several remaining taxa, for example:

3. Dalbergia greveana and similar, not safely distinguishable species (Madagascar)

1. vessels/pores present

2. storied structure present

3. number of tiers per axial mm: 5-6

4. wood semi-ring-porous

5. heartwood colour violet,

wherein D. cearensis and Pterocarpus macrocarpus are also shown as possible matches, which can be excluded only by knowing and entering a proven origin.

A decision as to which of the remaining species may be the best match is usually possible only in some cases by the direct comparison of the accompanying illustrations, preferably of the respective cross-sections.

More recently, other methods have been applied to the distinction of externally similar Dalbergia species, among them “Direct Analysis in Real Time” (DART) combined with “Time-Of-Flight Mass Spectrometry” (TOFMS). Details can be found in the following publication:

Espinoza, E.O., Wiemann, M.C., Barajas-Morales, J., Chavarría, G.D. & McClure, P.J. 2015. Forensic analysis of CITES-protected Dalbergia timbers from the Americas. IAWA Journal 36(3): 311-325.

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