Senna obtusifolia (L.) H.S.Irwin & Barneby
synonym | Cassia contorta Vogel |
synonym | Cassia humilis Collad. |
synonym | Cassia obtusifolia L. |
synonym | Cassia sunsub Forssk. |
synonym | Cassia tala Desv. |
synonym | Cassia tora sensu auct. |
synonym | Cassia tora Sensu auct. |
synonym | Cassia tora var. b Wight & Arn. |
synonym | Cassia tora var. humilis (Collad.) Collad. |
synonym | Cassia tora var. humilis (Collad.)Collad. |
synonym | Cassia tora var. obtusifolia (L.) Haines |
synonym | Cassia tora var. obtusifolia (L.)Haines |
synonym | Cassia toroides Raf. |
synonym | Cassia toroides Roxb. |
synonym | Chamaefistula contorta G. Don |
synonym | Diallobus falcatus Raf. |
synonym | Diallobus tora (L.) Raf. |
synonym | Diallobus uniflorus Raf. |
synonym | Emelista tora (L.) Britton & Rose ex Britton & P. Wilson |
synonym | Senna toroides Roxb. |
Comorian |
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Creoles and pidgins; French-based |
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Créole Seychelles |
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Malagasy |
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Malgache |
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Other |
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The genus Cassia was splited in Cassia, Chamaecrista and Senna, according to the following criteria :
Glands on the rachis and petiole | Petals | Stamens | Fruit | Bracteoles | Genus |
absent | subequal | 10 | indehiscent | present | Cassia |
absent or present | subequal | 10 or 7 fertil | indehiscent or dehiscent not elastic, valve not coiling | absent | Senna |
present | unequal | 10 or5 fertil | elastically dehiscent, valves coiling | present | Chamaecrista |
Distribution of Cassia spp. in the following table :
Old name | Valid name |
Cassia absus L. | Chamaecrista absus (L.) H.S.Irwin & Barneby |
Cassia alata L. | Senna alata (L.) Roxb.. |
Cassia fistula L. | Cassia fistula L. |
Cassia hirsuta L. | Senna hirsuta (L.) H.S.Irwin & Barneby |
Cassia javanica L. | Cassia javanica L. |
Cassia kirkii Oliv. | Chamaecrista kirkii (Oliv.) Standl. |
Cassia mimosoides L. | Chamaecrista mimosoides (L.) Greene |
Cassia nictitans L. | Chamaecrista nictitans (L.) Moench |
Cassia nigricans Vahl. | Chamaecrista nigricans (Vahl.) Greene |
Cassia obtusifolia L. | Senna obtusifolia (L.) H.S.Irwin & Barneby |
Cassia occidentalis L. | Senna occidentalis (L.) Link |
Cassia rotundifolia Pers. | Chamaecrista rotundifolia (Pers.) Greene |
Cassia siamea Lam. | Senna siamea (Lam.) H.S.Irwin & Barneby |
Cassia sieberiana DC | Cassia sieberiana DC |
Cassia tora L. | Senna tora (L.) Roxb. |
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Senna obtusifolia is an erect plant with alternate, paripinnately compound leaves. The leaves have 3 pairs of obovate leaflets, with a small tip at the apex. At the insertion point of the first pair of leaflets is a black rod- shaped gland. The flowers are yellow, solitary or in pairs at the leaf base. The large stamens have beak shaped anthers. The fruit is a long, slightly curved pod, containing a row of polygonal seeds.
Cotyledons
Subsessile and orbicular cotyledons. They measure about 20 mm in diameter. From the base of the lamina emerge 3 to 5 ribs.
First leaves
First leaves are alternate, composed and paripinnate. The first leaf has two pairs of leaflets, the following have three pairs.
General habit
Plant has an erect growth habit. It develops in herbaceous erect branched stem, or in small shrub. It can measure 1 m high.
Underground System
The root system is a deep taproot.
Stem
Solid and cylindrical stem. It is glabrous to finely pubescent. The base quickly becomes woody in plants of high bushy development.
Leaf
Leaves alternate and paripinnately compound. The petiole is almost as long as the rachis, the total length of the leaf may reach 15 cm. The base of the petiole is framed by 2 linear stipules of 1 cm long. The upper part of the petiole and the rachis is excavated in grooves. At the base of the first or of the first two pairs of leaflets, is a prominent rod-shaped gland, black in colour, measuring 1.5 mm long. Adults leaves include three pairs of obovate shape leaflets, the base is wedged, more or less asymmetrical and rounded mucronate top. The size of the leaflets increases from the base to the apex of the leaf. They are 2 to 6 cm long and 1.5 to 3 cm wide. The margin is entire, finely ciliate, the top face is glabrescent and the bottom face is finely pubescent.
Inflorescence
Flowers solitary or grouped in pairs at the leaf axils
Flower
Flowers carried by a pedicel of 1 to 3 cm long. A blossoming flower measure 2-3 cm in diameter. The calyx consists of 5 free sepals. The corolla is slightly asymmetrical and has five yellow obovate petals. The two ventral petals have a narrow base. Of the three dorsal petals, the central petal is deeply emarginated at the top. The stamens are free, and there are 10 in numbers and more or less abortive. The style of the ovary is 2 mm long and stick shaped.
Fruit
The fruit is a slightly arched linear pod. It is 15 to 25 cm long and 3 to 6 mm wide. The section of the pod is elliptical, the summit ends in a tapered beak. A pod contains 20-40 seeds longitudinally nested in a single series.
Seed
Seed almost cylindrical, slightly flattened laterally. It measures 5 to 6 mm long and 2 mm wide. The top and base are beveled. Shiny brown seed coat, decorated with a lighter mark in the shape of a stretched S, on each lateral surface.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Life cycle
Northern Cameroon: Senna obtusifolia is observed throughout the rainy season, although its frequency and abundance are higher in the beginning of the crop cycle than in the middle or end of the cycle. Germination takes place in the month of May following the first significant rains. Following each cultural operation (plowing, weeding, ridging), a new phase of germination occurs lasting 2-4 weeks. Flowering begins in late July-early August and ends in late September. Fruiting takes place from August to November, until the plant dries out early in the dry season. In the absence of weeding, the complete development cycle occurs in 12 or 13 weeks. In the case of individuals from later emergence, flowering and fruiting is delayed, but the development cycle is shortened to 8 or 9 weeks. Seed production is so low because it is produced by plants of weak development.
Mayotte : Senna obtusifolia flowers from March to August and fruits from May to September.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | dummy |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY_SA |
References |
Growth form
Leaf arrangement
Leaf type
Type of prefoliation
Latex
Stem section
Root type
Hollow or solid stem
Stipule type
Leaf attachment type
Fruit type
Pod type
Cotyledon type
Lamina base
Lamina margin
Lamina apex
Upperface pilosity
Upperface hair type
Lowerface pilosity
Lamina section
Lamina Veination
Flower color
Inflorescence type
Stem pilosity
Stem hair type
Life form
S. obtusifolia | S. tora | |
Number of rod glands | 1 | 2 |
anthers stamens | Beaked | Non beaked |
See also: Determination key of eight species of Cassia L. (Caesalpiniaceae), West African weeds.
Leaflets with accuminate apex | Glabrous leaflets (Upper surface) | S. occidentalis |
Densely pubescent leaflets | S. hirsuta | |
Leaflets with rounded apex | One rod shaped gland on the rachis of the leaf | S. obtusifolia |
Two rod shaped glands on the rachis of the leaf | S. tora |
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Senna obtusifolia usually grows as a pasture weed but sometimes found along roads and in disturbed areas in rain forest. In West Africa it occurs in open areas along roadsides, grasslands and cultivated fields, common near settlements, and in waste areas. It could probably thrive in disturbed areas of prairies.
S. obtusifolia is a ruderal species (along roads and irrigation canals, around the villages or cattle yards) and common weed of crops in plots where the soil is still fertile (cell cultures in floodplains, depressions and terraces).
Northern Cameroon: Senna obtusifolia is a characteristic species of the Sudano-Sahelian regions, where the annual rainfall is less than 1100 mm.
Mayotte: Senna obtusifolia is an exotic species but not frequent, and naturalized in secondarized environments such as wastelands, crops, ditches, or urban areas, mainly in the center part of the island.
West Indies: Although Senna obtusifolia is an undemanding species in terms of soil quality, it is characteristic of areas with low rainfall (less than 1100 mm) and therefore becomes less frequent in wetter areas.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Toxicity
Senna obtusifolia is toxic for cows if eaten in large quantities.
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Habitat
Geographical distibution
Origin
Senna obtusifolia is native to tropical America.
Worldwide distribution
This species is widespread in all tropical regions: Africa where it is very common, Indian Ocean Islands (Comoros, Madagascar, Reunion), Asia, Australia, New Caledonia, in these regions it is less common and often confused with Senna tora.
Attributions | dummy |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY_SA |
References |
Local harmfulness
Benin: Senna obtusifolia is rare and scarce in paddy fields.
Burkina Faso: Rare and scarce
Northern Cameroon: Senna obtusifolia is present in over 60% of the cultivated plots in Sudano-Sahelian region. However in more humid regions, where annual rainfall exceeds 1300 mm, the frequency of occurrence is very low (7%). It does not have any preference for any significant soil provided that it drains well. It is common and abundant on fersialitic soils, ferruginous soils of dunes and on alluvial, but it is uncommon in Vertisols because of their poor drainage. This is a very common weed in traditional farming systems, neither using herbicides nor fertilizers thus soil preparation before planting is superficial or non-existent. In these culture systems, sorghum is the dominant culture. S. obtusifolia is typically a regional weed.
Ivory Coast: Frequent and scarce.
Ghana: Rare and scarce.
Kenya: Frequent but not abundant
Mayotte: S. obtusifolia is a weed that is not frequent (2% of cultivated plots), it grows especially in vegetable crops.
Nigeria: Rare and scarce.
Uganda: Rare and scarce.
West Indies: Senna obtusifolia is a low pest species present in all crops. It can become locally abundant when conditions are favourable.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Global control
Senna obtusifolia is very difficult to control with cultivation usually spreading rather than controlling this weed. Hand pulling is difficult because of its long curved taproot. Slashing reduces vigour and if combined with other management measures such as restricted grazing and soil fertility augmentation, can bring this plant under control. A variety of herbicides can be used to control S. obtusifolia. Their success depends upon environmental conditions. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.
General guidelines for weed management in lowland rice, consult
For weeding Advice broadleaf annual weeds of irrigated rice and lowland in Africa, visit
Local control
Madagascar: Generally, Senna obtusifolia is slightly troublesome in crops. Pulling manually is difficult because of the strong taproot system. Controllable with oxadiazon preemergence and 2,4-D and / or glyphosate postemergence on young plants. Tolerant to most herbicides in the adult stage (also sensitive to dicamba postemergence, product not available in Madagascar).
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
- JSTOR PLANTE SCIENCE: http://plants.jstor.org/flora/flos001908
- Flora of Pakistan: http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=242311371
- Illinois wildflowers: http://www.illinoiswildflowers.info/prairie/plantx/sicklepodx.htm
- Grard, P., T. Le Bourgeois, J. Rodenburg, P. Marnotte, A. Carrara, R. Irakiza, D. Makokha, G. kyalo, K. Aloys, K. Iswaria, N. Nguyen and G. Tzelepoglou (2012). AFROweeds V.1.0: African weeds of rice. Cédérom. Montpellier, France & Cotonou, Bénin, Cirad-AfricaRice eds.
- BioNet-EAFRINET: http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Senna_obtusifolia_%28Sicklepod%29.htm
- Johnson, D.E., 1997. Weeds of rice in West Africa. WARDA, Bouaké. 212p.
- Australia Tropical Rainforest Plants: http://keys.trin.org.au:8080/key-server/data/0e0f0504-0103-430d-8004-060d07080d04/media/Html/taxon/Senna_obtusifolia.htm
- Lazarides, M., Cowley, K. and Hohnen, P. (1997). CSIRO Handbook of Australian Weeds. CSIRO Publishing, Collingwood, Victoria.
- Weed of Australia: http://www.weeds.org.au/cgibin/weedident.cgi?tpl=plant.tpl&ibra=all&card=H12
- Akobundu I. O. and Agyakwa C.W. (1998). A handbook of West African Weeds. International Institute of Tropical Agriculture, Ibadan, Nigeria 306p.
- Huat, J., Nagy, M., Carpente, A., Schwartz, M., Le Bourgeois, T. & Marnotte, P. 2021. Guide de la flore spontannée des agrosystèmes de Mayotte. Montpellier, Cirad. 150 p.
- Le Bourgeois, T., Carrara, A., Dodet, M., Dogley, W., Gaungoo, A., Grard, P., Ibrahim, Y., Jeuffrault, E., Lebreton, G., Poilecot, P., Prosperi, J., Randriamampianina, J.A., Andrianaivo, A.P., Théveny, F. 2008. Advent-OI : Principales adventices des îles du sud-ouest de l'Océan Indien.V.1.0. In Cirad [ed.]. Cirad, Montpellier, France. Cdrom.
- Barthelat, F. 2019. La Flore illustrée de Mayotte. Meze, Paris, France, Collection Inventaires et Biodiversité, Biotope – Muséum national d’Histoire naturelle. 487 p.
- Husson, O., H. Charpentier, F.-X. Chabaud, K. Naudin, Rakotondramanana et L. Séguy (2010). Flore des jachères et adventices des cultures. Annexe 1 : les principales plantes de jachères et adventices des cultures à Madagascar. In : Manuel pratique du semis direct à Madagascar. Annexe 1 - Antananarivo : GSDM/CIRAD, 2010 : 64 p.
- http://www.hear.org/pier/species/senna_obtusifolia.htm
- https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:234560-2
- Grossard, F., Le Bourgeois, T., Dumbardon-Martial, E. & Gervais, L. 2013. Adventilles - Guadeloupe & Martinique - Les adventices des Antilles françaises. Abymes, Guadeloupe, France, Les éditions du CTCS Guadeloupe.
- JSTOR PLANTE SCIENCE: http://plants.jstor.org/flora/flos001908
- Flora of Pakistan: http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=242311371
- Illinois wildflowers: http://www.illinoiswildflowers.info/prairie/plantx/sicklepodx.htm
- Grard, P., T. Le Bourgeois, J. Rodenburg, P. Marnotte, A. Carrara, R. Irakiza, D. Makokha, G. kyalo, K. Aloys, K. Iswaria, N. Nguyen and G. Tzelepoglou (2012). AFROweeds V.1.0: African weeds of rice. Cédérom. Montpellier, France & Cotonou, Bénin, Cirad-AfricaRice eds.
- BioNet-EAFRINET: http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Senna_obtusifolia_%28Sicklepod%29.htm
- Johnson, D.E., 1997. Weeds of rice in West Africa. WARDA, Bouaké. 212p.
- Australia Tropical Rainforest Plants: http://keys.trin.org.au:8080/key-server/data/0e0f0504-0103-430d-8004-060d07080d04/media/Html/taxon/Senna_obtusifolia.htm
- Lazarides, M., Cowley, K. and Hohnen, P. (1997). CSIRO Handbook of Australian Weeds. CSIRO Publishing, Collingwood, Victoria.
- Weed of Australia: http://www.weeds.org.au/cgibin/weedident.cgi?tpl=plant.tpl&ibra=all&card=H12
- Akobundu I. O. and Agyakwa C.W. (1998). A handbook of West African Weeds. International Institute of Tropical Agriculture, Ibadan, Nigeria 306p.
- Huat, J., Nagy, M., Carpente, A., Schwartz, M., Le Bourgeois, T. & Marnotte, P. 2021. Guide de la flore spontannée des agrosystèmes de Mayotte. Montpellier, Cirad. 150 p.
- Le Bourgeois, T., Carrara, A., Dodet, M., Dogley, W., Gaungoo, A., Grard, P., Ibrahim, Y., Jeuffrault, E., Lebreton, G., Poilecot, P., Prosperi, J., Randriamampianina, J.A., Andrianaivo, A.P., Théveny, F. 2008. Advent-OI : Principales adventices des îles du sud-ouest de l'Océan Indien.V.1.0. In Cirad [ed.]. Cirad, Montpellier, France. Cdrom.
- Barthelat, F. 2019. La Flore illustrée de Mayotte. Meze, Paris, France, Collection Inventaires et Biodiversité, Biotope – Muséum national d’Histoire naturelle. 487 p.
- Husson, O., H. Charpentier, F.-X. Chabaud, K. Naudin, Rakotondramanana et L. Séguy (2010). Flore des jachères et adventices des cultures. Annexe 1 : les principales plantes de jachères et adventices des cultures à Madagascar. In : Manuel pratique du semis direct à Madagascar. Annexe 1 - Antananarivo : GSDM/CIRAD, 2010 : 64 p.
- http://www.hear.org/pier/species/senna_obtusifolia.htm
- https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:234560-2
- Grossard, F., Le Bourgeois, T., Dumbardon-Martial, E. & Gervais, L. 2013. Adventilles - Guadeloupe & Martinique - Les adventices des Antilles françaises. Abymes, Guadeloupe, France, Les éditions du CTCS Guadeloupe.
Caractéristiques et facteurs biogéographiques de la répartition et de l’abondance des espèces adventices des systèmes herbagers de la Guyane Française
La flore des mauvaises herbes de la Canne à Sucre à La Réunion. Caractérisation à partir des témoins des essais d’herbicides. 2005-2016
Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Senna%2520obtusifolia
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Root | Root |
Kingdom | Plantae |
Phylum | Tracheophyta |
Class | Magnoliopsida |
Order | Fabales |
Family | Fabaceae |
Genus | Senna |
Species | Senna obtusifolia (L.) H.S.Irwin & Barneby |