for 14 Rubiaceae weed species

tC j j P of western and central Africa. 1 » . , -,aCT: ¿ y

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The biology and ecology of weed species must be fully defined before developing strategies to control them. An identification key was developed for Rubiaceae weed species based on vegetative characters, as is a followup to the key already drawn up for the Sida L. genus (VIAROUGE et a!., 1995).

The identification Rubiaceae family key

This key is meant to be an aid for the General characteristics identification of 14 Rubiaceae spe­ The Rubiaceae family is extremely large, including 500 genera and nearly cies of western and central Africa, 7 000 species (HEYWOOD, 1978). It is a cosmopolitan family, mainly of tropical belonging to five different genera species, but the herbaceous species are more common in temperate regions. (Table 1): Diodia Linn., Kohautia The leaves are entire, opposite, sometimes whorled, and have no stipules. The flowers Cham. & Schlecht., Mitracarpus are regular. The calyx is gamosepal and its basal part is fused with the Zucc., Oldenlandia Linn., and ovary. The corolla is formed by 4-5 petals fused at the base. There is the same number Spermacoce D ill, ex L. (formerly of stamens and petals. They are fused in the corolla tube or throat. The ovary generally Borreria G. F. W. Mey.). consists of 1 -10 loculi. The fruit is a capsule, berry or drupe. The seeds contain a fleshy albumen and are often winged.

Identification characters Economic importance Rubiaceae species are of considerable economic importance. The best known products Data for this identification key were are coffee (Coffea) and quinine (Cinchona). Some genera are used to produce dyes obtained from studies carried out on (Rubia, Uncaria), or are tapped for their medicinal properties (Cephaelis). There are also various flora species in different many ornamental plants in this family, such as Gardenia and Ixora. countries, i.e. in Senegal (BERHAUT, 1967), West Africa (HUTCHINSON et ai, 1958), Togo (BRUNEL, 1984), the Indian Ocean region (BOSSER et samples from CIRAD and the Institut Several keys were drawn up by ai., 1989) and Guadeloupe (FOUR- de Botanique (Montpellier, France). investigating different combinations NET, 1978). In addition, agronomic of characters (Table 2), but not all Eight vegetative characters (Table 2) reference works were consulted, were suitable for identifying the are taken into consideration in the along with an analysis of herbarium 14 species. A single key, applicable key: stem (shape, pubescence), leaf for all cases, was finally developed. (phyIlotaxis, lamina shape, pubes­ However, it is sometimes complica­ cence, margin), stipular sheath (size, ted to differentiate species belonging size of stipule segment). to the same genus because of varia­ J. SALAMERO, P. MARNOTTE, All identification characters are rea­ bility in the vegetative characters. In T. IE BOURGEOIS, A. CARRARA dily visible and no special botanical such cases, accurate identifications CIRAD-CA, BP 5 0 3 5 , knowledge is required to assess can be made on the basis of flower 3 4 0 3 2 Montpellier, France them. traits.

Agriculture et développement ■ Special issue - May 1 997 Table 1. Liste of species and synonyms. Starting point: Synonym lamina shape Diodia sarmentosa Swartz Diodia scandens Swartz, sensu FWTA, ed 2 Diodia breviseta Bentham The 14 species can be separated into Diodia pilosa Schumacher & Thonning Diodia ripatia Sagot two categories on the basis of lamina Diodia rubricosa Chev shape (Figure 1), i.e. those with a Spermacoce palmetorum DC. linear lamina and those with an Spermacoce pilosa (Schumacher & Thonning) DC. Spermacoce spinosa Loefl. oblong to elliptical lamina. Kohautia grandiflora DC. Oldenlandia grandiflora (DC.) Hiern In the oblong to elliptical lamina Kohautia senegalensis Cham. Schlecht Oldenlandia senegalensis (Cham. & Schlecht) Hiern group, Mitracarpus villosus is distin­ Oldenlandia confusa Hutch. & Dalz guished by its square stem with roun­ Mitracarpus villosus (Swartz) DC. Mitracarpus scaber Zuccarini Mitracarpus senegalensis DC. ded angles. Mitracarpus hirtus (Swartz) DC., sensu FL.Bras. Mitracarpus verticillatus (Schumacher & Thonning) Vatke If the stem angles are sharp, then it is Spermacoce hirta L. S. chaetocephala. Spermacoce villosa Swartz Staurospermum verticillatum (Schum. Thonn.) Leaf pubescence has to be assessed if Oldenlandia corymbosa Lin. Hedyotis alsinaefolia Br. the stem angles are winged. S. ocy­ Hedyotis burmanniana Br. moides has glabrous leaves, while Hedyotis corymbosa (L.) Lamk. Hedyotis biflora Roth. those of 5. latifolia are pubescent and Hedyotis graminicola Kuz. those of D. sarmentosa are scabrous Hedyotis intermedia W et A. on the upper surface and pubescent Cerontogea biflora Cham & Schlecht. Oldenlandia alsinifolia Don. underneath. Oldenlandia biflora Lam. Oldenlandia herbacea DC. In the linear lamina group, the leaves Oldenlandia ramosa Roxb. of S. verticillata are arranged in pseu- Oldenlandia scabrida DC. do-whorls. Oldenlandia herbacea (Linn.) Roxb. Hedyotis herbacea Linn. Oldenlandia Heynei G.Don In the group of species with opposite Oldenlandia Virgata Chev. leaves, the size of the dentate stipu- Spermacoce chaetocephala DC. Borreria chaetocephala (DC.) Hepper lary collar is the key feature. Among Borreria compacta Berhaut Borreria compacta (Hiern) K. Schumann the four species with a collar of Borreria ruclliae (F.W.T.A. not DC. ) K. Schumann 6 mm or less, Kohautia species can Spermacoce compacta (Hiern) be distinguished by a groove that is Spermacoce hebecarpa (A. Richard) O liv. var. minor Hiern Spermacoce hebecarpa Hotch. ex A. Richard Oliver present on all four sides of the stem. Spermacoce kotschyana Oliver The lamina of K. grandiflora is Spermacoce latifolia Aublet Borreria alata (Aublet) DC. 50-70 mm long and 3-5 mm wide, Borreria bartilingiana DC. while that of K. senegalensis is Borreria perrottettii DC. Borreria latifolia Aublet K. Schumann narrower and shorter (30-50 Borreria scaberrima Bold. X 2-3 mm). Spermacoce coerulescens Aublet Spermacoce octodon (Hepper) Lebrun & Stork Borreria octodon Hepper Oldenlandia species have a square Borreria meigei Assémien winged stem. O. herbacea differs Borreria setosa (Hiern) K. Schumann from O. corymbosa by its highly Borreria setosum Hiern Octodon setosum Hiern branched, totally glabrous stem and Spermacoce ocymoides Burman f. Borreria ocymoides (Burman f.) DC. its spherical tufted habit. Borreria ramisparsa DC. Borreria setidens Moq. Size of stipule segment is the next Spermacoce ramisparsa (DC.) Hiern trait to consider in species with a Spermacoce roxburghiana W all. sheath of more than 6 mm. In the two Spermacoce stricta Schlecht. Tardavel ocymoides (Burman f.) Hiern species with teeth that are markedly Spermacoce radiata (DC.) Sieber ex Hiern Borreria radiata DC. longer than the base of the sheath, Spermacoce ruelliae DC. Borreria articularis (L.f.) FN W illiams S. radiata can be readily identified by Borreria hispida (L.) Schumacher its cartilaginous white margin, while Borreria ruelliae (DC.) Schumann ex H. Thoms that of 5. octodon is scabrous. Borreria scabra (Schumacher & Thonning) K. Schumann Diodia scabra Schumacher & Thonning Stem shape should be assessed if the Spermacoce hispida L.f. sheath is the same size as the teeth. Spermacoce stachydea DC. Borreria stachydea (DC.) Hutchinson & Dalziel Spermacoce leucada Hotchstetter ex Hiern. 5. stachydea has a pubescent stem Borreria leucada (Hotchstetter ex Hiern.) K. Schumann with rounded angles, while Spermacoce verticillata L. Borreria verticillata (L.) G. Meyer S. ruelliea has winged angles and Spermacoce globosa Schumacher &Thonning sparser pubescence.

Agriculture et développement ■ Special issue - M ay 1997 Rubiaceae 10 to 10 15 10 to 10 15 10-15 10-15 -3 mm 1 1-2 1-2 mm 7 to 7 10 3-5 mm 3-4 3-4 mm 3 3 mm 3 3 mm to3 5 2-3 2-3 mm to 5 7 2-4 mm 5-12 mm slender slender 8-11 mm 5 to 5 7 2-3 mm 6-10 mm 5-7 5-7 mm 5 5 to 7 slender slender 5-7 mm slender slender slender slender Stipule segment 10-14 mm to 12 16 pubescent 13-18 mm 7-10 mm to 8 10 3-5 3-5 mm to 1 3 3-6 mm5-9 mm pubescent to 1 3 7-15 mm to 7 10 pubescent 8-13 mm pubescent 6-10 mm 6-8 mm 3-5 3-5 mm to 1 3 4-8 mm Stipulary sheath scabrous and and scabrous scabrous scabrous scabrous 7-10 mm cartilaginous scabrous scabrous Margin Size withglabrous glabrous withglabrous toothed base scabrous 3-6 mm cartilaginous white and toothed base Under pubescent scabrous pubescent pubescent pubescent scabrous scabrous glabrous* scabrous surface glabrous* or scabrous glabrous* scabrous glabrous* glabrous* glabrous Upper pubescent pubescent pubescent variable glabrous* or scabrous glabrous* glabrous* scabrous scabrous scabrous slightly scabrous glabrous glabrous glabrous glabrous glabrous surface scabrous glabrous variable from glabrous to scabrous mm Lamina 10-25 10-25 X X 15-40 x mm1-2 15-30x5-12 mm linear-lanceolate linear linear linear-lanceolate linear linear linear linear-lanceolate 30-90 x 5-16 mm linear-lanceolate 30-90 x 7-20 mm 30-50 x 5-10 mm 30-50 x2-3 mm 30-60 50-70 x 1-2 mm 30-60 x 7-15 mm -4 mm 20-40 x 1 30-70 x 4-15 mm 50-80 x 20-30 mm 50-80 x 3-5 mm oblong-elliptical 30-60 mm Shape Shape and size oblong-lanceolate elliptical-lanceolate elliptical-lanceolate oblong-lanceolate Phyllotaxis pseudo-whorls decussate opposite opposite opposite opposite decussate opposite decussate opposite opposite opposite opposite opposite in opposite opposite decussate decussate pubescent opposite pubescent pubescent opposite hispid pubescent pubescent pubescent scabrous angles angles scabrous smooth sides glabrous smooth sides scabrous angles angles scabrous smooth sides slightly glabrous glabrous angle slightly scabrous glabrate glabrous species ofwestern and central Africa. Stem Rubiaceae rounded angles rounded angles round rounded angles square square Shape Pubescence square, winged square, square grooved on square, wingedsquare, angles scabrous square withsquare square, wingedsquare, glabrous square winged square, withsquare square, winged square, square, winged square, square withsquare variable glabrous to grooved on each side each each side finely striated Kohautia villosus verticillata Diodia Kohautia Oldenlandia corymbosa Oldenlandia herbacea chaetocephala latifolia radiata ruelliae Spermacoce Spermacoce exceptglabrous aroundThe * is of the under leaves the veins. surface senegalensis sarmentosa Mitracarpus Spermacoce Spermacoce Spermacoce octodon Spermacoce stachydea Species Spermacoce ocymoides Spermacoce Tableau 2. Characteristics of grandiflora

Agriculture et développement ■ Special issue - May 1997

O O í Rubiaceae

Species descriptions are given to Mitracarpus vitiosus enable the user to confirm the identi­ fication of species with similar vege­ ñ tative structures. fil Spermacoce chaetocephala U\ S/Hirmacoce ocymoidcs

Species Spermacoce laiifolia R i-l'" -1 descriptions Diodia sarmentosa All are herbaceous species, generally with a square stem. The leaves are Spermacoce verticillata entire and opposite, and the median veins on the upper surface are Kohautia senegalensis depressed. They are sessile to subses- a sile, and the lamina base terminates Kohautia grandiflora with a dentate stipulary sheath. The white flowers, pink- and sometimes Oldenlandia coymbosa blue-tinged, are arranged in axillary SS or terminal inflorescences and rarely solitary. The entire leaf margins are Oldenlandia herbacea scabrous or partially scabrous.

Spermacocc radiata Diodia sarmentosa Swartz Spcrmacoce octodon

Cartilaginous w h ite maiRin

Spermacoce stachydea

Scabrous maiyçin

Spermacoce ruelliae

Figure 1. Identification key for Rubiaceae species.

Kohautia Cham. & stipular sheath is fine (3-5 mm) and tipped with 1-3 teeth (3 mm) each Schlecht. side of the leaf base. Although both species may be reco­ gnized by the size of the lamina, identification is easier if the plants D. sarmentosa is a weed of forest are flowering. regions with a creeping branched habit. The slender stem is square and winged, and only the angles are K. grandiflora pubescent. The oblong-lanceolate lamina (30-60 x 10-25 mm) is sca­ K. grandiflora has red to pink flowers brous above and pubescent under­ arising from a short pedicel neath. The stipular sheath (7-10 mm (1-2 mm). The corolla has an oval high) is tipped with several pointed lobe. The corymbiform inflorescence teeth (5-7 mm long). is compressed. The fruit is a sessile K. grandiflora and K. senegalensis globular capsule. From a vegetative D. sarmentosa is similar to S. latifo­ are upright (up to 90 cm tall). All viewpoint, the stem of K. grandiflora lia, but the latter species has a pubes­ sides of their square stems are can be slightly scabrous at the cent stem, while only the stem angles grooved from top to bottom. The angles, with a linear lamina of 50- of D. sarmentosa are pubescent. leaves are linear and glabrous. The 70 mm x 35 mm.

Agriculture et développement ■ Special issue - May 1997 Rubiaceae

Similar species with two loculi, each containing a seed. The small, white flowers are Although Kohautia species are simi­ arranged in axillary glomerules. lar to Spermacoce octodon and S. radiata in appearance (linear leaf, This species is common throughout upright habit), their short stipular intertropical Africa, and could have sheath with 1-3 teeth distinguishes been first introduced from the West them from the two Sperm acoce Indies during the 19th century. species, which have multiple pointed dentation sheaths. Oldenlandia corymboso Linn. Mitrocorpus villosus (Swartz) DC.

Kohautia grandiflora. Photo H. Merlier

K. senegalensis K. senegalensis has single white to deep-pink flowers, arising from a 2- 10 mm long pedicel. They are arran­ ged in a diffuse inflorescence. The corolla has a linear lobe. The fruit is a globular pendunculate capsule. The linear lamina (30-50 x 2-3 mm) is narrower and shorter than that of K. grandiflora.

Oldenlandia corymbosa. Photo T. Le Bourgeois

Mitracarpus villosus. Photo T. Le Bourgeois O. corymbosa has a semi-upright habit (20-40 cm) and grows in slight­ M. villosus is characterized by a ly branched, diffuse tufts. The square square pubescent stem with rounded slender stem is finely winged, with angles. The elliptical lanceolate scabrous angles. The linear-lanceo- leaves (30-60 x 7-15 mm), with short late leaves (2040 x 1-4 mm) are petioles, have a lamina that is always connected to a stipular sheath tipped glabrous underneath, but only slight­ with 3-5 teeth. The lamina is dark ly scabrous, pubescent or glabrous green, slightly pubescent and can be somewhat scabrous above, while it is Kohautia senegalensis. above. M. villosus can also be reco­ Photo T. Le Bourgeois gnized by its fruit, i.e. a pyxidium pale green and glabrous underneath.

Agriculture et développement ■ Special issue - M ay 1 997 The flowers form pauciflorous white flowers are sessile and grou­ corymbs of 2-5 white flowers. The ped in dense glomerules of about fruit is an oval dehiscent capsule 2 cm. with two loculi containing many seeds. This species is generally encountered on degraded sandy soils or as a rude- ral species. It is present in all hot regions of the world.

Oldenlandia herbacea (Linn.) Roxb.

Spermacoce chaetocephala. S. chaetocephala could be confused Photo T. Le Bourgeois with species with a linear lamina, but the lateral leaf veins are marked and protrude underneath. stipular sheath (7-15 mm) is tipped with pointed teeth that are longer There are two varieties of this spe­ than the base of the sheath. cies, according to the Flora of West Tropical Africa (HUTCF1INSON et This weed, which originates from al., 1958): S. chaetocephala var. South America, flourishes in forest chaetocephala, with a robust stem regions. and a 4-15 mm lamina, and S. chae­ O. herbacea has an upright tufted tocephala var. minor, with a slender habit (7-60 cm). The winged square stem and a lamina that is never wider Spermacoce octodon stem is glabrous and highly bran­ than 4 mm. ched. The leaves are linear (15-40 x (Hepper) Lebrun & Stork 1-2 mm) and glabrous. The stipular collar is short (26 mm) with 1-3 tee­ Spermacoce latifolia th. The flowers are generally solitary. The fruit is a round bilocular capsule Aublet containing many smooth brownish seeds. It is possible to distinguish the two species by their habit. O. herbacea is upright and grows in compact tufts, w hile O. corymbosa has a semi­ upright habit, and a slender stem with relatively little branching. In addition, O. corymbosa flowers are S. octodon is a savanna weed with grouped while those of O. herbacea an upright habit (20-50 cm). The are generally solitary. leaves are linear (50-80 x 3- 5 mm), slightly scabrous above and glabrous underneath. A narrow, lightly pubes­ Spermacoce cent stipular sheath extends from the leaf base. The sheath (13-18 mm) has chaetocephala DC. many very fine teeth that are marked­ ly longer (8-11 mm) than the base. S. chaetocephala is an upright plant 5. latifolia can be identified by its The white flowers are arranged in a that can grow up to 60 cm high. The blue-tinged flowers, grouped in den­ terminal glomerule. stem is square and glabrous with sca­ se axillary glomerules, and by its brous angles. The linear elliptical creeping habit. It has a winged, squa­ The stipular sheath distinguishes leaves (30-70 x 4-15 mm) are pubes­ re, pubescent stem, with roots some­ 5. octodon from Kohautia species, cent to scabrous. The stipular sheath times growing from the nodes. The i.e. Kohautia plants have a sheath is pubescent, tipped with sharp pubescent leaves are oblong- with only 2-3 teeth, and all sides of 2-4 mm teeth (5-7). The many small lanceolate (50-80 x 20-30 mm). The their stems are grooved.

Agriculture et développement ■ Special issue - M ay 1997 59 Rubiaceae

Spermacoce ocymoides Burmann f.

Spermacoce ruelliae. Photo M . Déat

5. ruelliae grows abundantly In crop­ fields of savanna regions. It has a 5. ocymoides has a slender square square winged stem with scattered stem with winged and scabrous hairs. The leaves are linear-lanceola- angles. The leaves are oblong ellipti­ Spermacoce ocymoides. te (30-90 x 5-16 mm) and scabrous, cal (15-30 x 5-12 mm), pale green Photo H. Merlier and paler underneath as compared and glabrous. The short stipular to the upper surface. The stipular sheath (5 mm) has 5-7 small teeth. sheath (10-14 mm) has 12-16 teeth There are many small white to pink (5-7 mm). The white flowers are sup­ flowers that grow in non-spherical ported by fine leaf bracts and form glomerules. terminal and axillary glomerules. It is common throughout tropical Africa Spermacoce radiata and prefers clay soils. Sieber ex Hiern It is quite similar to S. stachydea, but can be distinguished by its stem shape.

Spermacoce stachydea DC.

S. radiata Is characterized by its Spermacoce radiata. white cartilaginous leaf margins and Photo H, Merlier its pubescent stipular sheath with many teeth that are markedly longer Spermacoce ruelliae DC. than the base. The pubescent to hispid stem is round and somewhat reddish in colour. The lamina S. stachydea has an upright habit, is linear (30-60 x 4-6 mm) and gla­ and can grow up to 60 cm high. The brous. The many small white flowers square pubescent stem has rounded are sessile and form terminal or angles. The leaves have a linear lan­ sub-terminal glomerules. ceolate and densely scabrous lamina This species is quite common in (30-90 x 7-20 mm). They have a degraded ferruginous soils of savan­ short indistinct petiole, extended by na regions. a broad pubescent stipular sheath.

Agriculture et développement ■ Special issue - M ay 1997 Rubiaceae

stipular sheath has 5-7 teeth. The BRUNEL J.-F., HIEPKO P., SCHOLZ H., white flowers form small, dense axil­ 1984. Flore analytique du Togo. GTZ, Eschborn, Germany, p. 398-437. lary glomerules. This ruderal species flourishes in Sudano-Cuinean clima­ CARRIERE R.,1994. Plantes de Guinée à l'usage des éleveurs et des vétérinaires. tic zones. CIRAD-EMVT, Montpellier, France, 167 p. DEAT M., 1981. Principales adventives du cotonnier en Afrique de l'Ouest. Description et techniques de lutte. CIRAD-IRCT, Montpellier, France, p. 82-84. FOURNET J., 1978. Flore illustrée des phanérogames de Guadeloupe et de Martinique. INRA, Paris, France, p. 1 155- 1 220. FOURNET J., HAMMERTON J.-L., 1991. Weeds of the lesser Antilles. Mauvaises herbes des petites Antilles. INRA, Paris, France, p. 136-138. GARCIA J.G.L., MACBRYDE B„ MOLINA A.R., HERRERA-MACBRYDE O., 1 975. Malezas prevalentes de America Central. International Plant Protection Center, Spermacoce stachydea. El Salvador, San Salvador, p. 127-128. Photo T. Le Bourgeois HEYWOOD V.FH., 1978. Flowering plants of the world. Oxford University Press, Oxford London, Melbourne, p. 257-259. The sheath has many teeth that are HUTCHINSON J., DALZIEL J.M., ciliated at the apex. The flowers are HEPPER F.N., 1958. Flora of West Tropical arranged in false capitulae mixed Africa, vol II, second Edition. The Whitefriars with leaves. Press (éd.), London and Tonbridge, UK, 544 p. Spermacoce verticillata. S. stachydea and S. ruelliae are mor­ IVENS G.W., MOODY K, EGUNJUB J.K., Photo M . Déat phologically quite similar, but can be 1978. West African weeds. Oxford University distinguished by their stems and Press, Ibadan, Nigeria, p. 172-174. leaves. S. stachydea has a round LE BOURGEOIS T., MERLIER H „ 1995. stem, more pubescent that that of Adventrop. Les adventices d'Afrique soudano- sahélienne. CIRAD-CA, Montpellier, France, S. ruelliae, which is square with win­ 640 p. ged angles. The leaves of S. stachy­ LECONTE H., HUMBERT H., dea are more scabrous than those of Bibliography GAGNEPAIN F., 1922. Flore générale de S. ruelliae and have a short petiole. l'Indochine, vol III. MASSET et Cie (Eds), Paris, In addition, the sheath teeth of S. sta­ France, p. 146-147, p. 441 -442. AKONBUNDU I.O., AGYAKWA C.W., chydea MERLIER H., 1994. Actualisation de are ciliated at the apex. 1987. A handbook of West African weeds. quelques synonymies (3e édition). CIRAD-CA, IITA, Oyo Road, PMB 5320, Ibadan, Nigeria, Montpellier, France, 145 p. p. 366-377 MERLIER H., MONTEGUT J., 1982. Spermococe verticillata L. BACKER C.A., 1973. Atlas of 220 weeds Adventices Tropicales. ORSTOM, CIRAD- of sugar-cane fields in Java. Greshoff's GERDAT, ENSH, Montpellier, France, 490 p. Rumphius Fund, Amsterdam, Netherlands, p. 649-677. OGUNYEMI S., MOODY K., 1972. Some Weeds at IITA. IITA, Ibadan, Nigeria, 57 p. BAYER A.G., 1992 . Important Crops of the W orld and their Weeds (Scientific and PEYRE DE FABREGUES B„ LEBRUN J.-P., Common Names, Synonyms and WSSAAVSSJ. 1976. Catalogue des plantes vasculaires du Approved Computer Codes). 2e edition, Niger. CIRAD-IEMVT, Montpellier, France, BAYER (Ed.), Leverkussen, Germany, p. 238-243. 1 465 p. SOERJANI M., KOSTERMANS A.J.G.H., BERHAUT J., 1 967. Flore du Sénégal. TIJTROSOEPOMO G., 1987. Weeds of rice in Clairafrique éditeur, Dakar, Senegal, 485 p. Indonesia. Balai pustaka. Jakarta Pusat, Indonesia, p. 492-540. BOSSER )., CADET T., G UEHO J., MARAIS W., 1989. Flore des Mascareignes, la VERNON R., 1983. Field guide to Réunion, Maurice, Rodrigues. The Sugar important arable weeds of Zambia. Mount 5. verticillata can be identified by its Industry Research Institute, Mauritius, Makulu Central, Research Station, Department of Agriculture, Chilanga, Zambia, leaves, which are arranged in pseu- ORSTOM, Paris, The Royal Botanic Gardens, Kew, UK, p. 1-62. p. 72. do-whorls, and by its highly bran­ BOUDET G., LEBRUN J.-P., VIAROUGE N., MARNOTTE P., ched and upright habit. The leaves DEMANGE R., 1986. Catalogue des plantes MERLIER H., 1995. Détermination pratique are linear-lanceolate (30-50 x 5- vasculaires du Mali. CIRAD-IEMVT, Maison- des mauvaises herbes du genre Sida L. 10 mm) and glabrous. The short fine Alfort, France, p. 238-245. Agriculture et développement 8 : 43-50.

Agriculture et développement ■ Special issue - May 1997 Rubiaceae

Abstract... Résumé... Resumen

J. SALAMERO, P. MARNOTTE, T. LE BOURGEOIS, J. SALAMERO, P. MARNOTTE, T. LE BOURGEOIS, J. SALAMERO, P. MARNOTTE, T. LE BOURGEOIS, A. CARRARA — Practical identification key for A. CARRARA — Détermination pratique de A. CARRARA — Determinación práctica de 14 Rubiaceae weed species of western and 14 rubiacées, adventices d'Afrique de l'Ouest 14 rubiáceas adventicias del Africa occidental central Africa. et du Centre. y central. Some weeds of the Rubiaceae family have been identified Des adventices de la famille des rubiacées ont été Se han identificado adventicias de la familia de la in western and central Africa. An identification key was identifiées en Afrique de l'Ouest et du Centre. Une clé de rubiáceas en Africa occidental y central. Una clave de developed using eight plant structure characters. A table détermination comprend 8 caractères de l'appareil identificación incluye ocho caracteres del aparato of these criteria and description of how to use the key are végétatif. Le tableau de ces critères, la démarche de la clé vegetativo. Se presentan el cuadro de dichos criterios y el presented, without full plant descriptions. sont présentés, sans faire appel à une description procedimiento de la clave sin recurrir a una descripción complète des plantes. completa de las plantas. Keywords : weed, Rubiaceae, Doidia sarmentosa, Kohautia grandiflora, Kohautia senegalensis, Mitracarpus Mots-clés : mauvaise herbe, Rubiaceae, Diodia Palabras clave : maleza, Rubiaceae, Diodia sarmentosa, villosus, Oldenlandia corymbosa, Oldenlandia herbacea, sarmentosa, Kohautia grandiflora, Kohautia senegalensis, Kohautia grandiflora, Kohautia senegalensis, Mitracarpus Spermacoce chaetocephala, Spermacoce latifolia, Mitracarpus villosus, Oldenlandia corymbosa, Oldenlandia villosus, Oldenlandia corymbosa, Oldenlandia herbacea, Spermacoce octodon, Spermacoce ocymoides, Spermacoce herbacea, Spermacoce chaetocephala, Spermacoce Spermacoce chaetocephala, Spermacoce latifolia, radiata, Spermacoce ruelliae, Spermacoce stachydea, latifolia, Spermacoce octodon, Spermacoce ocymoides, Spermacoce octodon, Spermacoce ocymoides, Spermacoce Spermacoce verticillata, identification, plant structure, Spermacoce radiata, Spermacoce ruelliae, Spermacoce radiata, Spermacoce ruelliae, Spermacoce stachydea, Africa. stachydea, Spermacoce verticillata, identification, Spermacoce verticillata, identificación, aparato appareil végétatif, Afrique. vegetativo, Africa.

Agriculture et développement ■ Special issue - May 1997