IAWA Bulletin n.s., Vol. 13 (2),1992: 135-150 WOOD ANATOMY OF THE BAPHIA GROUP (LEGUMINOSAE) by R.W. den Outer and W.L.H. van Veenendaal Department of Plant Cytology and Morphology,Agricultural University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands Summary The secondary xylem of 5 of the 6 genera The distribution of the three subfarnilies is belonging to the Baphia-group (viz. Airyan­ mainly tropical and subtropical. The Papilion­ tha, Baphiastrum, Leucomphalos, Dalhousiea oideae constitute a much !arger group than the andBaphia) and Ormosia (Leguminosae-Pa­ others and is the only one which is common pilionoideae-Sophoreae) was studied, in or­ in temperate regions. It has a worldwide der to aid generic delimitation in the Baphia­ range, with most of the woody representa­ group. tives in the tropics and southern hemisphere. Storied-structure features, vessel-member The herbaceous and shrubby members of the length, structure of rays and axial parenchy­ Papilionoideae usually are found in temperate ma, and presence of crystals were used to regions, with a high concentration in mediter­ discuss generic delimitation. Based on the ranean regions (Heywood 1971). The Mimos­ number of cells per axial parenchyma strand oideae are woody; the Caesalpinioideae are two groups are recognised: Airyantha and primarily woody and rarely herbaceous. Baphiastrum have 2-4 cells, Leucomphalos, The Papilionoideae consist of 10 to 11 Dalhousiea and Baphia have fusiform paren­ tribes into which the genera are grouped on chyma or 2-celled strands. Ormosia is very features of habit, leaf morphology and degree different from the other genera which c10sely of fusion of the stamens (Chant 1979). The resemble each other. A c1ear wood anatomi­ position ofthe tribe Swartzieae, if included in cal separation of the genera belonging to the the Papilionoideae, and not in the Caesalpini­ Baphia-group is not possible. Especially oideae as is often done, is debatable. Also Airyantha and Baphiastrum are almost iden­ Sophoreae s.l. is a tribe of convenience be­ tical wood anatomically and could be com­ tween the Caesalpinioideae and the bulk of bined into a single genus. There are only the Papilionoideae, and not sharply defined minor differences between Leucomphalos, from either subfarnily. The Sophoreae are Dalhousiea and Baphia. mostly trees, shrubs, lianas or, rarely, herbs. Key words: Airyantha, Baphia, Baphiastrum, The leaves are pulvinate, pinnately I-many­ Dalhousiea, Leucomphalos, Ormosia, sys­ foliolate or digitately 3-foliolate, sometimes ternatic wood anatomy. stipellate; stamens free (Polhill 1981). The tribe contains nearly fifty genera, most of which are small and discrete, except for Introduction Baphia, Ormosia and Sophora. Sophoreae The Leguminosae constitute a relatively are divided into 8 groups, of which only the natural taxon which can be divided into three Sophora-group extends significantly outside subfarnilies, viz. Caesalpinioideae, Papilion­ the tropics. The Baphia-group, here consid­ oideae and Mimosoideae. It is a matter of ered, consists of 6 genera. Five genera (Airy­ opinion whether these three groups should be antha, Baphiastrum, Bowringia, Dalhousiea treated as subfarnilies or as separate farnilies: and Leucomphalos) only include a few spe­ Caesalpiniaceae. Papilionaceae and Mimosa­ eies (2, 2, 4, 3 and 1 respectively), whereas ceae (Hutchinson 1964). Baphia includes c. 60 species (Polhill1981). Downloaded from Brill.com09/24/2021 12:31:54PM via free access 136 IAWA Bulletin n.s., Vol. 13 (2),1992 Several plant taxonomists feel that the mated in cross sections; the remaining part is number of genera in the Baphia-group has to occupied by both vessels and ray tissue. The be reduced. The present investigation was amount ofaxial parenchyma is given as a undertaken to find wood anatomical argu­ percentage of the ground tissue and of the ments for or against such areduction. Sam­ total cross sectional area. pIes of 5 genera of the Baphia-group were We have used the definition of libriform available; of Bowringia no sampies could be fibres given by Reinders (1935) and Jans­ obtained. Because Airyantha might belong sonius (1940), which in this case equals the to the Ormosia-group (with 3 genera, viz. description ofthe IAWA Committee (1989). Ormosia, Pericopsis, Haplormosia) of the Ends cells ofaxial parenchyma strands Sophoreae, some Ormosia species were also seen in tangential seetions may be gable- or investigated and compared with descriptions conical-shaped (Reinders-Gouwentak & Rijs­ given by Reinders-Gouwentak and Rijsdijk dijk 1955). Near the top of gable-ended eells (1968). Wood anatomie al evidence is often the longitudinal walls more or less abruptly useful in matters of generic, tribal and sub­ bend into an oblique plane forming a roof­ familial delimitation. However, differences at like top or gable (see Figs. 6, 16, 19). The the species level generally are less clearly ex­ angle of the gable may be obtuse but often is pressed in the wood than in external features slightly less than 90 degrees; the angle at the (Bareua-Kuipers 1981). abrupt bending is always obtuse. In the top part of conical ended eells the longitudinal walls gradually bend towards each other Materials and Methods forming a cone-shaped cell top (see Fig. 24); With the exception of Ormosia sampies, the angle of the top is always sharp, often this investigation is based on material from mueh less than 90 degrees. When the angle tropical Africa. The species studied are listed of the gable is small (about 30 degrees), the below, arranged alphabetically, viz. Airyan­ angle at the abrupt bending is large (about tha with 1 species and 7 sampies; Baphia 165 degrees) and then the end cells of the with 20 species, 41 sampies; Baphiastrum parenchyma strands are almost conical­ with 1 species, 5 sampies; Dalhousiea with 1 shaped and conical ones are then always also species, 5 sampies; Leucomphalos with 1 spe­ present in the species. The greater the angle eies, 2 sampies; Ormosia with 5 species, 5 of the gable-end, the smaller the abrupt bend­ sampies. In total 65 sampies belonging to 29 ing angle, and the smaller the chance that also species and 6 genera. conical-ended top cells are present in the spe­ Anatomical features were studied in trans­ eies. verse, radial and tangential seetions and in Combination types of rays are according macerations. All seetions were embedded in to Baretta-Kuipers (1973) based on features Kaiser's gelatin-glycerin. Means and ranges described by Reinders-Gouwentak and Rijs­ of the different eharaeters are based on twenty­ dijk (1955) and Reinders-Gouwentak (1955). five or more individual measurements. Tan­ Rays investigated by her and by us are nearly gential vessel diameters are given and vessel always homocellular, composed of procum­ member length was measured including the bent cells, sometimes with one or a few rows tails. of nearly square or upright cells at the mar­ In the wood description quantitative data ginal parts. Rays may be either uniseriate, are given as a range of mean values of the or mostly uniseriate and partly multiseriate, different sampies and/or species usually fol­ or almost entirely multiseriate with short lowed between braekets by extremes of all uniseriate marginal parts. In some speeies the sampies together, or as a single mean these different kinds of rays oceur together, value if there is no range (mean values are in others two of the three kinds are found. equal for the different sampies of a species or The ratio of the three kinds of rays can be for the different species of a genus). used for differentiating between the species. Ground tissue percentages for libriform Baretta-Kuipers (1973) distinguished four fibres and axial parenehyma together are esti- different combinations, viz.: Downloaded from Brill.com09/24/2021 12:31:54PM via free access Den Outer & Van Veenendaal - Wood anatomy of the Baphia group 137 - combination I, in which the uniseriates Tw & Uw, Dechamps 1410, Angola, small dominate (more than 80%) and the partly tree, 8 cm; Tw, FHOw 18235, Zambia, or entirely multiseriates constitute a small small tree, 5 cm. - B. cf. descampsii De part of the whole; Wild.: Kw, Jefford & Newbould 2071, Tan­ - combination 11, in which most of the rays zania, shrub, 4 cm. - B. dewevrei De Wild.: are uniseriate (60-80%), but quite a num­ Tw, Dechamps 1334, Congo, shrub, 2 cm.­ ber are partly or whoIly multiseriate; B. gracilipes Harms: RBHw, Jentsch 84, - combination III, in which most of the rays Cameroun, small tree, over 10 cm. - B. lau­ are multiseriate (60-80%), but a consid­ rentii De Wild.: RBHw, Gottwald Z 25, Zaire, erable number are partly or entirely uni­ large tree, 40 cm; Tw, Dechamps 222, Zaire, seriate; small tree, 4 cm. -B. laurifolia BailI.: Tw, - combination IV, in which multiseriates Louis 3619, 7031, Zaire, shrub, both 1.5 dominate (more than 80%) and the partly cm; RBHw, Jentsch 87, Cameroun, shrub, or wholly uniseriates constitute but a smaIl over 1.5 cm. - B. leptobofrys Harms: Tw & part of the total number. CTFw, Floret 559, Cameroun, shrub, 10 cm. -B. marceliana De Wild.: Tw, Dechamps List of studied material 129, Zaire, shrub, c. 10 cm. - B. massaien­ Each name is foIlowed by an abbreviation sis Taub.: Tw, Dechamps 1241, 1276, An­ (according to Stern 1988) of the location of gola, small tree, 5 cm; Uw, Dechamps 1326, wood sampie and herbarium voucher, collec­ Angola, small tree, 12 cm. -B. nitida Lodd.: tor and number, geographical origin, habit, Tw, Chalk, Sierra Leone, small tree, over 5 and stern diameter of the sampie. cm; Tw, Gavage, Gabon, small tree, over 5 CfFw = Division d'anatomie des bois, cm; Tw, Detienne 53, Ivory Coast, small Centre Technique Forestier Tropical, Nogent­ tree, over 5 cm; CTFw, Adam 5758, Guinee, sur-Mame, France; Kw = Economic and Con­ small tree, 7 cm; WAGw, Bos 3390, Camer­ servation Seetion, Herbarium, Royal Botanic oun, small tree, 4 cm; WLw, Versteegh & Gardens, Kew, England; RBHw = Bundes­ Den Outer 47, Ivory Coast, small tree, 7 cm.