IAWA Journal, Vol. 27 (1), 2006: 99–114 WOOD ANATOMY OF THE TRIBE CAESALPINIEAE (LEGUMINOSAE, CAESALPINIOIDEAE) IN VENEZUELA Narcisana Espinoza de Pernía and José Luis Melandri Laboratorio de Anatomía de Maderas, Facultad de Ciencias Forestales y Ambientales, Universidad de Los Andes, Mérida, Venezuela SUMMARY We studied the microscopic wood anatomy of 8 genera and 30 species in the tribe Caesalpinieae, subfamily Caesalpinioideae, with a focus on the identification and comparative anatomy of these genera. Characters suitable for reliable identification include intervessel pit size, fibre wall thickness, septate fibres, storied structure, ray type, ray width, and silica bodies. A table of diagnostic characters, generic descriptions, and phot- omicrographs provide tools for identification and descriptive information for comparative and phylogenetic studies. Key words: Leguminosae, Caesalpinioideae, Caesalpinieae, wood anat- omy, Venezuela. INTRODUCTION The subfamily Caesalpinioideae comprises 160 genera and about 2175 species, most of which are tropical and subtropical trees and shrubs (Barneby et al. 1998; Herendeen et al. 2003). Recent studies divide it into four tribes: Caesalpinieae, Cassieae, Cercideae and Detarieae (GRIN Taxonomy 2001; ILDIS Legume Web 2002; Missouri Botanical Gardenʼs VAST 2002). Several authors have studied the wood anatomy of tribes, genera or species in the subfamily Caesalpinioideae. Cozzo (1951) studied the wood anatomy of the Argen- tinean Mimosoideae and Caesalpinioideae with many valuable observations. In 1955 Reinders-Gouwentak studied storied structure and taxonomic rank within the legumes. She showed that storied structure was an important feature and that many taxa have storied rays. Koeppen (1980) studied the arborescent Leguminosae with silica bodies in their wood. He found that only eight genera of subfamily Caesalpinioideae have silica bodies in their secondary xylem, including Tachigali and Sclerolobium of the tribe Caesalpinieae. Loureiro and Silva (1981) described the wood of 7 species of Dimorphandra and Loureiro et al. (1983) described 5 species of Sclerolobium and 5 species of Tachigali. Barajas-Morales and León (1989) studied the wood anatomy of species from Mexico, two of which are Caesalpinia spp. that also occur in Venezuela. Angarita (1991) described 7 species of Campsiandra from Venezuela. Later Espinoza de Pernía et al. (1998) described Schizolobium amazonicum and S. parahybum from Associate Editor: Alex Wiedenhoeft Downloaded from Brill.com10/04/2021 11:57:04AM via free access 100 IAWA Journal, Vol. 27 (1), 2006 Espinoza de Pernía & Melandri — Wood anatomy of Caesalpinieae 101 Venezuela. In 1981 Baretta-Kuipers published a comparative study of wood anatomy of the Leguminosae. She surveyed the entire family and distinguished two groups of Caesalpinioideae on the basis of ray features and parenchyma characteristics. Ranjani and Krishnamurthy (1988) showed a table of species of some Caesalpiniaceae with vestured pits. Wheeler and Baas (1992) studied the xylem evolution and ecological anatomy of legumes in fossil wood. In 1992 Nardi and Edlmann published a study of commercially important tropical woods used in Italy. They included a dichotomous key for diagnostic characters and described the macro and micro structure of 116 woods, 2 of which are Caesalpinieae from Venezuela, and also included photomicrographs. In 1999 Höhn reported on 23 West African genera of Caesalpinioideae and Mimosoideae. These were grouped into types according to wood structure, and although a key was not given, a synoptic table of characters was included. Miller and Détienne (2001) provided anatomical descriptions, photomicrographs and a dichotomous key of approximately 80 Guyanese timbers. Among these 20 legume genera were included. Herendeen (2000) reported the occurrence of morphological and anatomical characters with possible phylogenetic implications; some of these characters, such as the occurrence of vestures in vessel element pits may be phylogenetically informative in defining a large clade near the base of the family. In 1994 Gasson published on the wood anatomy of the tribe Sophoreae and related Caesalpinioideae and Papilionoideae, and in 2003 Gasson et al. gave a comprehensive account of the wood anatomy of the Caesalpinioideae. These papers reflect how wood anatomy can be used to derive diagnostic and phylogenetic information. The wood anatomy and identification of Venezuelan Caesalpinioideae is currently being studied by the present authors. Some genera of the tribe Caesalpinieae in Venezuela are trees with commercial tim- ber importance. particularly Caesalpinia coriaria, C. granadillo, Mora excelsa, M. gong- grijpii (Mora 1974; JUNAC 1981; Arroyo 1983; INIA 1996; Aristeguieta 2003), Sclero- lobium (Aristeguieta 1973) and Tachigali paniculata (= Sclerolobium paniculatum) (Arroyo 1983). Others, such as Caesalpinia spp., Delonix regia (Aristeguieta 1973, 2003; Hoyos 1994) and Schizolobium parahyba (Hoyos 1994), are important as ornamental trees, in gardens, city avenues and parks. Caesalpinia coriaria is important in the tanning and dye industries (Aristeguieta 2003) and was exported to North America in earlier times (Hoyos 1994, 1985; Mabberley 1997). Caesalpinia granadillo is an endemic species in the dry zone of northern Venezuela (Hoyos 1985) and others such as Campsiandra curaara, C. emonensis, C. macrocarpa, C. nutans, C. pasibensis and C. velutina are endemic species in Venezuelan Guayana (Stergios 1996; Barneby et al. 1998). The present paper provides information on the microscopic structure of the wood, according to the proposed terminology in the List of Microscopic Features for Hard- wood Identification (IAWA Committee 1989), of 30 species of the tribe Caesalpinieae with their main distribution in Venezuela. The microscopic wood anatomy of the tribe Caesalpinieae was studied because of its great importance in the timber industry and the complexity of its anatomy. The anatomical descriptions, table of diagnostic features and photomicrographs provide tools for the identification of the genera and groups within the tribe Caesalpinieae. Downloaded from Brill.com10/04/2021 11:57:04AM via free access 100 IAWA Journal, Vol. 27 (1), 2006 Espinoza de Pernía & Melandri — Wood anatomy of Caesalpinieae 101 MATERIALS AND METHODS We examined 46 specimens representing 30 Venezuelan species from 8 of 11 genera in the tribe Caesalpinieae (Leguminosae, Caesalpinioideae): Caesalpinia (4/7), Camp- siandra (9/18), Delonix (1/1), Dimorphandra (4/8), Mora (2/2), Schizolobium (2/2), Sclerolobium (1/2), and Tachigali (7/19). No material was available to us of the genera Haematoxylon, Jacqueshuberia and Recordoxylon, which each have one species in Venezuela. The majority of the specimens were collected in Venezuela and are specimens from wood collections at the Laboratorio de Anatomía de Maderas de la Facultad de Ciencias Forestales y Ambientales de la Universidad de Los Andes, Mérida, Venezuela (MERw) and at the USDA Forest Service, Forest Products Laboratory, Madison, Wis- consin, USA (MADw and SJRw). Terminology and methodology followed the List of Microscopic Features for Hard- wood Identification (IAWA Committee 1989). For vessel diameters, vessel element lengths, fibre lengths and ray height 25 measurements were taken from each specimen and averaged. The values reported [e.g. 30 (50–110) 150 μm], are minimum value, range of averages, and maximum value. The measurements are accurate only to the 10 μm level, and are reported accordingly. For other quantitative values the most frequent range is reported. Generic descriptions follow in alphabetical order and features not listed in the generic descriptions are either absent or do not apply. Preparation of slides for the microscopic study was made following the methodology used at MERw (Corothie 1967). Photomicrographs were taken using a film camera with a light microscope. We followed the scientificnames in database ILDIS (http://www.ildis.org/Legume Web/) for all names except for Tachigali and Sclerolobium; for them we used the web site Grin Taxonomy (http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl?language= sp) and W3Tropicos (http://mobot.mobot.org/W3T/Search/vast.html), because there is a discrepancy concerning synonymy between ILDIS and the other databases. RESULTS Generic descriptions Caesalpinia L. — Fig. 1 & 2 Growth rings indistinct to distinct, marked by marginal parenchyma bands and/or thick-walled fibres in C. coriaria, C. ebano, C. granadillo; absent in C. sclerocarpa. Diffuse porous. — Vessels solitary and in radial multiples of 2–4, occasionally in clusters; 4–18 per mm2; 30 (50–110) 150 μm in diameter; 110 (130–170) 250 μm in element length. Simple perforation plates. Alternate intervessel pits; circular or oval, small to medium, 5–8 μm in diameter. Vessel-ray pits with distinct borders, similar to intervessel pits in size and shape; pits vestured. Dark brown gum-like deposits abundant in vessels. — Fibres non-septate; thick-walled to very thick-walled; 700 (850–1260) 1350 μm in length. — Axial parenchyma mostly in narrow bands or lines, up to three cells wide or bands more than three cells wide. Marginal banded parenchyma present in C. coriaria, C. ebano and C. granadillo. Paratracheal parenchyma vasicentric and aliform to confluent; aliform parenchyma winged, occasionally unilateral. Apotracheal parenchyma rarely diffuse-in-aggregates in C. ebano. Axial parenchyma 2–4 cells Downloaded from Brill.com10/04/2021 11:57:04AM via