Sida rhombifolia
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Overview
Aperçu
Regulation :
Remarques Réglementation:
Regulation Notes:
Distribution :
Répartition :
Sida rhombifolia is widely distributed in tropical, subtropical and warm temperate regions of the world, and commonly reported in Asia, Central and South America as an undesirable species (Holm et al. 1997). In Europe, S. rhombifolia has been found in Portugal, Czechoslovakia and Belgium (POWO 2023). The species is found in the southeastern United States as far north as Kansas and Virginia (Smith et al. 1992; FNA 1993+). It is not present in Canada (Brouillet et al. 2010+).
Habitat and Crop Association :
Habitat et Cultures Associées :
S. rhombifolia can grow in variable soil types and fertility levels, but prefers undisturbed soils, such as pastures (Holm et al. 1997). This species can grow in cultivated fields, it is more common in no-till or conservation tillage (Holm et al. 1997). It is frequently reported as a weed in pastures, Saccharum officinarum L. (sugar cane) and Oryza sativa L. (rice); less frequently in Phaseolus vulgaris L. (beans), Manihot esculenta Crantz (cassava), Coffea L. spp. (coffee), Gossypium hirsutum L. (cotton), Glycine max (L.) Merr. (soybeans) and Zea mays L subsp. mays (maize) (Holm et al. 1997).
Economic Use, cultivation area, and Weed Association :
Utilisation économique, zone de culture et association de mauvaises herbes :
Duration of Life Cycle :
Durée du cycle vital:
Perennial
Dispersal Unit Type :
Type d’unité de dispersion :
Seed
General Information
RENSEIGNEMENTS GÉNÉRAUX
Sida rhombifolia plants have been used medicinally in China and India, as a vegetable in Central America, and for fiber and brooms (Holm et al. 1997). It is a short-lived perennial, and will only flower after a year or more of growth (Smith et al. 1992). Soil tillage will break up the root system and remove the plant, reducing infestations in fields under regular tillage (Smith et al. 1992).
Plants are estimated to produce 4000-11600 seeds per year, dispersed by mericarps attaching to animal fur or clothing, or by floating on water (FNA 1993+; Holm et al 1997). S. rhombifolia seed had a high germination on the soil surface compared to S. spinosa, suggesting that S. rhombifolia is able to establish under fluctuating environmental conditions without seed burial (Smith et al. 1997).
S. rhombifolia has been described as a species complex, with diploid and tetraploid forms and a range of leaf shapes and pubescence (Ugborogho 1982; Sivarajan and Pradeep 1994). Ugborogho (1982) described three subspecies of S. rhombifolia in Nigeria with different ploidy level, leaf shape and pollen size: S. rhombifolia subsp. alnifolia, S. rhombifolia subsp. retusa and S. rhombifolia subsp. rhombifolia.
Sivarajan and Pradeep (1994) split S. rhombifolia in India with distinct pubescence types, density and leaf shape into four species: S. alnifolia (includes subspecies retusa, sensu Ugborogho 1982), S. rhomboidea, S. rhombifolia and S. scabrida. In North America, S. rhombifolia is not divided into subspecies, and S. alnifolia is a separate species that includes S. retusa (FNA 1993+; USDA-ARS 2023).
.Identification
Identification
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Schizocarp
Size
- Schizocarp diameter: 4-5 mm (FNA 1993+)
Shape
- Circular, slightly cone-shaped in 3D due to mericarp awns angled towards the centre of the schizocarp
Surface Texture
- Schizocarp surface has shallow, transverse wrinkles, may be glabrous, glandular or short-hairy (Verdcourt 2004)
Colour
- Schizocarp is yellowish-brown coloured
Other Features
- Schizocarp contains 8-14 wedge-shaped mericarps (FNA 1993+; Verdcourt 2004)
- Schizocarp is enclosed in 5 diamond-shaped sepals
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Mericarp
Size
- Mericarp size: length*: 2.0 – 2.4 mm; width: 1.2 – 1.7 mm
*Note: minimum and maximum of 10 mericarps in a normal range of this species using image measurement (ISMA 2020)
Mericarp size from literature:
• length: 3-4 mm (FNA 1993+)
• length: 3-3.5 mm (Verdcourt 2004)Shape
- Mericarps are D-shaped, sectoroid in 3D
- 2 short spines extend from one end of the mericarp along the narrow side
Surface Texture
- The curved edge of the mericarp has shallow, transverse wrinkles with one longitudinal central nerve
- The sides of the mericarp are thin with a network of nerves
- Mericarp surface may be glabrous, finely glandular or with short hairs (Verdcourt 2004)
Colour
- Mericarps are dark yellowish-brown coloured
Other Features
- The sides of the mericarp is fibrous and breaks apart between the nerves
- Mericarp spines are 1 mm in length (FNA 1993+), glabrous, and oriented towards the centre when attached in a schizocarp
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Seed
Size
- Seed size: length*: 1.8 – 2.1 mm; width: 1.1 – 1.3 mm
*Note: minimum and maximum of 10 seeds in a normal range of this species using image measurement (ISMA 2020)
Seed size from literature:
• Length: 1.25-2 mm (Holm et al. 1997)Shape
- Seed is heart shaped with radicle and cotyledon lobes, sectoroid in 3D
Surface Texture
- Seed surface is smooth; stippled under 30x magnification
Colour
- Seeds are dull dark reddish brown coloured
- Seed coats have a thin layer of translucent, dull, yellowish tissue that can separate from the seed coat near the hilum or be rubbed off during seed processing.
Other Features
Hilum and hilum area
- The hilum end of the seed is notched with yellowish-brown tissue and crinkled hairs
- Hilum area within a notch, covered by a flap of tissue that separates in mature seed
- Hilum is surrounded by radiating striations
Other than hilum
- Cotyledon lobe larger than radicle lobe of the seed
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Embryo
Size
- Embryo partially fills the seed
Shape
- Embryo is bent, in a peripheral position (Martin 1946)
Endosperm
- Hard, translucent yellowish coloured
Other Features
- Embryo is yellowish coloured
- Embryo cotyledons are folded
Identification Tips
CONSEILS POUR L’IDENTIFICATION
The Malvoidae subfamily with the Malvaceae generally have circular, schizocarpic fruits with several wedge-shaped mericarps and persistent sepals. The genus Sida has a 10 ribbed calyx, a hard mericarp coat and 2 spines at one end of the mericarp (Fryxell 1987; FNA 1993+). S. rhombifolia mericarp awns were short and up to 14 mericarps were contained in a schizocarp, a high number for the genus (FNA 1993+; Weeds of Australia 2023).
Additional Botany Information
AUTRES RENSEIGNEMENTS BOTANIQUES
Flowers/Inflorescence
- Flowers yellow, 15-20 mm diameter, petals 7-9 mm long (FNA 1993+; Weeds of Australia 2023)
- Calyx lobes 5-6 mm long each with a central rib, side ribs, and stellate hairs (FNA 1993+)
Vegetative Features
- Vegetative parts of the plant with stellate pubescence
- Leaf stalks 5-10 mm long; leaf blades 2.5-9 cm long (FNA 1993+)
- Leaves are generally diamond (rhombic) shaped, but can be oblong, egg-shaped or oval with dense pubescence on the upper surface (FNA 1993+; Weeds of Australia 2023)
Similar Species
ESPÈCES SEMBLABLES
Similar species are based on a study of seed morphology of various species, and those with similar dispersal units are identified. The study is limited by physical specimen and literature availability at the time of examination, and possibly impacted by the subjectivity of the authors based on their knowledge and experience. Providing similar species information for seed identification is to make users aware of similarities that could possibly result in misidentification.
Sida spinosa L.
S. spinosa is an annual weedy species that has a larger agricultural impact than S. rhombifolia (Smith et al. 1992). The mericarps (length*: 2.3 – 2.6 mm; width: 1.9 – 2.1 mm) and seeds (length*: 1.8 – 2.1 mm; width: 1.5 – 1.7 mm) are a similar size compared to S. rhombifolia. There are 5 mericarps in a S. spinosa schizocarp, with dense, raised reticulate nerves and pubescent spines compared to 8-14 mericarps of S. rhombifolia with sparse nerves and glabrous spines (FNA 1993+; Weeds of Australia 2023). The seeds of S. spinosa have yellowish reticulations visible at 20x magnification that were not observed on seeds of S. rhombifolia.
*Note: minimum and maximum of 10 mericarps or seeds in a normal range of this species using image measurement (ISMA 2020)
Sida cordifolia L.
The perennial S. cordifolia is believed to have originated in India, and is considered both an invasive weed and medicinal plant (FNA 1993+). The mericarps are a similar size (length**: 2.2 – 2.6 mm; width 1.1 – 1.2 mm) as S. rhombifolia. The mericarp spines (length 2.5-3.5 mm) are longer and have barbs that point backwards (retrorse) compared to the shorter, glabrous spines of S. rhombifolia (FNA 1993+; Weeds of Australia 2023).
**Note: minimum and maximum of 5 mericarps in a normal range of this species using image measurement (ISMA 2020)
Click to select species
Cliquez pour sélectionner les espèces
Sida spinosa
Sida cordifolia
Comparison Window
Fenêtre de comparaison
MAIN SPECIES
ESPÈCES PRINCIPALES
Sida rhombifolia
Sida rhombifolia
Malvaceae
Sida rhombifolia mericarps
MAIN SPECIES
ESPÈCES PRINCIPALES
Sida rhombifolia
Sida rhombifolia
Malvaceae
Sida rhombifolia seeds
MAIN SPECIES
ESPÈCES PRINCIPALES
Sida rhombifolia
Sida rhombifolia
Malvaceae
Sida rhombifolia seeds and mericarps
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Sida spinosa
Sida spinosa
Malvaceae
Sida spinosa mericarps
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Sida spinosa
Sida spinosa
Malvaceae
Sida spinosa seeds and mericarps
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Sida spinosa
Sida spinosa
Malvaceae
Sida spinosa seeds
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Reference(s)
Référence(s)
Brouillet, L., Coursol, F., Meades, S. J., Favreau, M., Anions, M., Bélisle, P. and Desmet, P. 2010+. VASCAN, the database of vascular plants of Canada. http://data.canadensys.net/vascan/ Accessed July 13, 2023.
Flora of China (FOC) 1994+. Sida rhombifolia Vol. 12 Page 271 (English edition). http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200013764 Accessed November 01, 2023.
Flora of North America (FNA) Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford. http://beta.floranorthamerica.org. Accessed July 13, 2023.
Fryxell, P.A. 1978. Neotropical segregates from Sida L. (Malvaceae). Brittonia, 30: 447-462.
Holm, L., Doll, J. Holm, E. Pancho, J., and Herberger, J. 1997. World Weeds: Natural History and Distribution. John Wiley & Sons, Inc., New York 1129 pp.
Martin, A.C. 1946. The comparative internal morphology of seeds. The American Midland Naturalist 36: 513-660.
Plants of the World Online (POWO) 2023. Facilitated by the Royal Botanic Gardens, Kew. http://www.plantsoftheworldonline.org/ Accessed 13 July, 2023.
Smith, C.A., Shaw, D.R., and Newsom L.J. 1992. Arrowleaf sida (Sida rhombifolia) and prickly sida (Sida spinosa): germination and emergence. Weed Research 32: 103-109.
Ugborogho, R.E. 1982. Cytogenetic studies on the Sida rhombifolia complex in Nigeria. Cytologia 47: 11-20.
U.S. Department of Agriculture-Agricultural Research Services (USDA-ARS). 2023. Germplasm Resources Information Network (GRIN), https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch Accessed November 01, 2023.
Verdcourt, B. 2004. The variation of Sida rhombifolia L. (Malvaceae) in East Africa. Kew Bulletin 59: 233-239.
Weeds of Australia. 2023. Sida rhombifolia Fact Sheet. https://keyserver.lucidcentral.org/weeds/data/media/Html/sida_rhombifolia.htm Accessed July 17, 2023.
Wiersema, John, H. and Blanca León. 2016. World Economic Plants. Available from: VitalSource Bookshelf, (2nd Edition). Taylor & Francis.