Family : Malvaceae
Text © Pietro Puccio
English translation by Mario Beltramini
Cultivated since remote times, its precise origin country is unknown, it is thought being Africa, has naturalized in various tropical and subtropical regions, where grows in open areas and at the margins of water streams, from the sea level up to hilly altitudes, characterized by high rainfall well distributed all along the year.
The name of the genus comes from the Latin “hibiscum”, name utilized by Pliny (23-79) to indicate the Althaea officinalis, in its turn derived from the Greek “ibiskos”, referred to some Malvaceae; the specific name comes from a local term used in India.
Common names: Indian-sorrel, Jamaica-sorrel, red-sorrel, roselle, sorrel, sour-sour (English); bissap, Carcadé, Karkadé (Arabic); chukiar (Assamese); chukar (Bengali); mei gui qie, luo shen kui, shan qie zi (Chinese); oseille de Guinée, thé rose d’Abyssinie (French); gongura, lal lambari (Hindi); carcadè (Italian); carurú-de-Guiné, quiabo-azedo, quiabo-de-Angola, quiabo-róseo, quiabo-roxo, rosela, vinagreira (portuguese-Brazil); ambasthaki (Sanskrit); acedera de Guinea, rosa de Jamaica, serení (Spanish); ufuta, ufuta dume (Swahili); Hibiscus-Tee, Malvantee, Rosella (German); erragomgura, gongura (Telegu); kra chiap daeng (Thai); rau chua (Vietnamese).
The Hibiscus sabdariffa L. (1753) is an annual or biennial herbaceous species, up to more than 3 m tall, with little ramified erect stem, usually reddish, glabrous or slightly pubescent. The leaves, on a 1-10 cm long petiole, are alternate, 7-15 cm long, usually ovate in the lower part of the stem, palmate-ovate in the upper one, with three-seven oblong-lanceolate lobes with serrate margins and obtuse apex, 2-8 cm long and 0,5-1,5 cm broad.Axillar flowers, on 2-3 cm long pubescent peduncle, usually solitary, hermaphroditic, with epicalyx (involucre of bracts similar to sepals located under the calyx, typical of the Malvaceae) formed by 8-12 lanceolate lobes, 0,5-1,5 cm long, with thorny appendix in proximity to the apex, of red colour. Campanulate calyx, with 5 triangular lobes with pointed apex, 1-2 cm long, provided externally of short thorns and sparse hairs, of dark red colour, fleshy and enlarged, up to 6 cm long and of 3-3,5 cm of diameter, in fruit. Campanulate corolla of 6-8 cm of diameter of yellow or pale pink colour with dark red centre, formed by 5 obovate 5 cm long and 3 cm broad petals, and 2 cm long staminal column.
It is a brevidiurnal species, therefore the blooming begins when the hours of darkness exceed those of light. The fruits are ovoid capsules with pointed apex, about 2,5 cm long and of 1,5 cm of diameter, pubescent, containing several reniform seeds, about 0,5 cm long, of dark brown colour.
It reproduces by seeds, that germinates in 1-3 weeks, in organic draining loam maintained humid at the temperature of 24-26 °C, with beginning of the blooming, in the best cultivation conditions, after about two months.
Species cultivable in the tropical and humid subtropical regions, needs high temperatures, over the 20 °C, lower values slow down the growth up to stopping it around the 15 °C, whilst the death of the plant can occur after some days with temperatures under the 10 °C. It requires an exposition in full sun and is not particular concerning the soil, provided well drained, but prefers the sandy ones rich of organic substance maintained constantly humid, even if it can stand short dry periods thanks to the deep radical apparatus.
The plant has a vegetative cycle of 6-8 months, therefore can be cultivated also in less favourable climates sowing in protected environment in late winter and transferring the young plants outside when the temperatures allow this. All parts of the plant are edible, but the most utilized is the calyx that contains, besides a high quantity of citric acid, malic and ascorbic acids, pectin and anthocyanins, vitamins and minerals, employed fresh in salads and soups, as well as dry for preparing various drinks among which one much popular in Africa, known as karkadé, consumed warm and also cold with addition of sugar. The calyces, which feed a flourishing trade, are also utilized for syrups, jellies, preserves, cakes and for colouring and aromatizing various dishes.
The leaves and the young buds are consumed either raw or cooked as vegetables and the fermented seeds, that contain proteins, lipids, minerals and vitamins, are employed in Africa as seasoning and for aromatizing various preparations. The resistant fibres gotten from the stem, similar to the jute (Corchorus capsularis L. and Corchorus olitorius L.), from plants selected for this purpose that may reach the height of 5 m, are utilized for fabricating ropes, nets, sacks, etc. Since remote times flowers and leaves, and in lesser extent seeds and roots, are utilized in the traditional medicine of various populations; laboratory studies have evidenced the presence in various parts of the plant, but especially in the calyx, of bioactive compounds with antimicrobic, antitumoral, antioxidant, antihypertensive, hepatoprotective, hypocholesterolemic, anti-inflammatory and anxiolytic activity. Finally, are not to be neglected its ornamental characteristics, as garden plant, and those of the calyces that are employed in the floral compositions.
Synonyms: Hibiscus fraternus L. (1775); Sabdariffa rubra Kostel. (1836); Hibiscus cruentus Bertol. (1840); Abelmoschus cruentus (Bertol.) Walp. (1842); Hibiscus palmatilobus Baill. (1885); Furcaria sabdariffa Ulbr. (1921).