Botany
Roselle is an erect, branched, nearly smooth annual herb, 1 to 2 meters in height. Stems are purplish. Leaves are 8 to 12 centimeters long, variable in shape, entire or deeply 3- or 5-lobed, the lobes oblong to oblong-lanceolate. Calyx is somewhat hairy, lobes are pointed, connate below the middle, forming a fleshy cup. Corolla is pink with a dark center, about 5 centimeters long. Fruit is ovoid, pointed, hairy, about 2.5 centimeters long, enclosed by a fleshy and enlarged calyx.

Distribution
- Planted for ornamental purposes and its edible calyces.
- Not spontaneous.
- Introduce post-Spanish colonization.
- Native of tropical Africa.
- Now pantropic..

Constituents
• The dried calyces yield among others: cellulose, insoluble and soluble ash, tartaric acid, malic acid.
• Calyces are high in calcium, niacin, riboflavin, and iron.
• Food value per 100 g of fresh edible portion: Moisture 9.2 g, protein 1.145g. fat 2.61g, fiber 12 g, ash 6.9 g, calcium 1,263 mg, phosphorus 273.2 mg, iron 8.98 mg, carotene 0.029 mg, thiamine 0.117 mg, riboflavin 0.277 mg, niacin 3.765 mg, ascorbic acid 6.7 mg.
• The flowers yield a coloring matter that contain gossypetin, quercetin, hibiscetin and free protocatechuic acid.
• Bitter seeds contain 20% oil with 26% albuminoids.
• Leaves yield oxalic acid.

Properties
• Leaves considered emollient, stomachic, scorbutic and febrifuge.
• Seeds are diuretic and tonic.
• Flowers considered tonic and aperitive.

Parts used
Leaves and flowers.

Uses
Culinary / Nutritional
• Cultivated ornamentally and for the red and fleshy calyces that surround the fruit used for making jellies, wine and other food products. The jam, jelly, and sauce are similar in appearance and taste to cranberries.
• Young leaves used as a substitute for spinach; used in cooking of curries, meat or fish, and the native dish "sinigang."
• In Myanmar, green leaves are the main ingredient in making chin baung kyaw curry.
• Calyces are high in calcium, niacin, riboflavin, and iron.
Folkloric
• Leaves used as emollient.
• Lotion made from leaves used for sores.
• Decoction of seeds used for dysuria and strangury; for mild dyspepsia and debility.
• In Brazil, drink made from the plant, considered refrigerant and used for fevers.
• A a boiled drink prepared from the fruit and calyx, dashed with salt, pepper, asafoetida and molasses, used for biliousness.
• Fruit used as antiscorbutic.
• Seeds are diuretic and tonic.
• In Chad, infusion of calyces used for plethora, bronchitis and coughs.
• Heated leaves applied to cracks in the feet; also, to boils and ulcers to hasten healing and maturation.
• In India seed decoction used for dysuria, strangury and mild dyspepsia.
Others
Fiber: Plant yields bast fiber from the stems; used a jute substitute in making burlap.
Coloring: Plant yields a coloring matter used for food coloring.

Studies
• Antihypertensive: (1) A study evaluating the effect of sour tea (H sabdariffa) on essential hypertension showed significant lowering of both systolic and diastolic blood pressure. (2) Study showed the aqueous seed extract of HS produced a significant reduction in cat blood pressure.
• Antimutagenic: A study of an 80% ethanol extract of roselle showed antimutagenic activity against MAM acetate, a colon carcinogen.
• Antiviral / Anti-Measles Virus: A study of leaf extracts of red and green leaved Hibiscus sabdariffa showed antiviral activities against the Measles Virus.
• Anti-Atherosclerotic / Hypolipidemic: A study of HB extract suggests it inhibits serum lipids and shows and anti-atherosclerotic activity.
• Nephroprotective / Diabetic Nephropathy Amelioration: Study showed HS extract possesses potential effects to ameliorate diabetic nephropathy in STZ induced type 1 diabetic rats via improving oxidative status and regulating Akt/Bad/14-3-3 signaling.
• Galactagogue / Lactogenic Effect: (1) A study showed the seed extract of H sabdariffa possesses lactogenic activity, enhancing serum prolactin level which is the principal lactogenic hormone secreted by the anterior pituitary. Results establish the ethnomedical use of the seeds as a galactagogue. (2) Study showed the serum prolactin level of extract-treated rats showed a dose-dependent significant increase when compared to the control group.
• Anti-Hyperammonemia: A study showed administration of extract of HS altered the activities of the liver marker enzymes in ammonium chloride-induced hyperammonemic rats.
• Antioxidant: (1) A study showed the protective role of extract of HS against lipid peroxidation and suggests an antioxidant potential to be used for therapeutic purposes. (2) Study investigated the antioxidant activity of an ethanolic seed extract of H sabdariffa in toxicity induced by chronic administration of sodium nitrate in wistar rats. Results showed alleviation of induced toxicity by the antioxidant effect of HS.
• Hypolipidemic: A study of HS dried calyx ethanolic extract on the serum lipid profile of Sprague-Dawley rats showed triacylglycerols and LDL levels to be significantly less in all groups. All groups had lower cholesterol levels compared to control. No significant results were found on the HDL levels.
• Hepatoprotective: A study of the aqueous ethanol extract of the calyx of Hibiscus sabdariffa on carbon tetrachloride-induced liver damage showed healing of oxidative liver damage as determined by serum enzyme levels and liver thiobarbituric acid reactive substances levels.
• Anti-Obesity: Study investigated the effect of a calyx extract on fat absorption-excretion and body weight in rats. Results showed a significant increasein the amount of fatty acid in the feces. The components of the Hs extract at the intermediate and higher concentrations could be considered possible antiobesity agents.
• Staining Effect: Roselle extract shows reasonable potential as a candidate nuclear stain especially whe modanted with iron alum or mordanted with potassium alum and acidified with acetic acid.
• Safety Study: Study concludes Hibiscus sabdariffa is probably a safe medicinal plant, short-term administration of the HS did not show harmful effects on body water and electrolyte levels.
• Review / Hypertension Study / No Effect: Current trials of HS in reducing high blood pressure were poor. Four randomized controlled studies do not provide reiable evidence to support recommending HS for the treatment of primary hypertension in adults.

Availability
Wild-crafted.
Cultivated.
Teas and extracts in the cybermarket.