Manihot esculenta Crantz

  • Authority

    Rogers, David J. & Appan, S. G. 1973. Manibot, Manihotoides (Euphorbiaceae). Fl. Neotrop. Monogr. 13: 1-272. 1 chart. (Published by NYBG Press)

  • Family

    Euphorbiaceae

  • Scientific Name

    Manihot esculenta Crantz

  • Type

    TYPE. Fig 4 & Fig 5 in Merian, Dissertatio de generatione et metamorphosibus insectorum Surinamensium. 1726. (Lectotype selected by Rogers & Appan in accordance with Art. 9, Intern. Code Bot. Nomen. Crantz, while describing Manihot esculenta, does not cite any specimen but cites Merian's figures).

  • Synonyms

    Jatropha manihot L., Jatropha dulcis J.F.Gmel., Jatropha mitis Rottb., Jatropha janipha L., Jatropha stipulata Vell., Manihot aipi Pohl, Manihot aipi var. lutescens Pohl, Manihot aipi var. lanceolata Pohl, Manihot aipi var. latifolia Pohl, Manihot utilissima var. castellana Pohl, Manihot utilissima var. castellana Pohl, Manihot utilissima var. sutinga Pohl, Manihot flabellifolia Pohl, Manihot digitiformis Pohl, Manihot diffusa Pohl, Manihot dulcis var. diffusa (Pohl) Pax, Manihot loureirii Pohl, Mandioca utilissima Link, Manihot edule A.Rich., Manihot melanobasis Müll.Arg., Mandioca dulcis Parodi, Manihot manihot (L.) Cockerell, Manihot sprucei Pax, Manihot flexuosa Pax & K.Hoffm., Manihot esculenta subsp. flabellifolia var. coalescens (Pohl) Cif., Manihot esculenta subsp. flabellifolia var. nodosa (Pohl) Cif., Manihot esculenta subsp. flabellifolia var. digitifolia (Pohl) Cif., Manihot esculenta subsp. flabellifolia var. debilis (Pohl) Cif., Manihot esculenta subsp. flabellifolia var. flavicaulis (Pohl) Cif., Manihot esculenta subsp. flabellifolia var. fuscescens, Manihot esculenta subsp. flabellifolia var. argentea, Manihot esculenta subsp. flabellifolia subsect. alboerecta var. ramosissima Cif., Manihot esculenta subsp. flabellifolia subsect. alboerecta var. luteola Cif., Manihot esculenta subsp. flabellifolia subsect. alboerecta var. hispaniolensis Cif., Manihot esculenta subsp. flabellifolia subsect. alboerecta var. rufescens Cif., Manihot esculenta subsp. flabellifolia subsect. alboerecta var. domingensis Cif., Manihot esculenta subsp. flabellifolia subsect. alboerecta var. mutabilis Cif., Manihot esculenta subsp. flabellifolia subsect. diffusa var. jamaicensis (Pohl) Cif., Manihot esculenta subsp. flabellifolia subsect. diffusa var. fertilis (Pohl) Cif., Manihot esculenta subsp. flabellifolia subsect. diffusa var. pohlii (Pohl) Cif., Manihot esculenta subsp. flabellifolia subsect. diffusa var. zimmermannii (Pohl) Cif., Manihot esculenta subsp. flabellifolia subsect. diffusa var. communis (Pohl) Cif., Janipha manihot var. angustiloba Torr., Manihot palmata var. aipi (Pohl) Müll.Arg., Jatropha flabellifolia Pax & K.Hoffm., Manihot palmata var. flabellifolia (Pohl) Müll.Arg., Manihot dulcis var. flabellifolia (Pohl) Pax, Jatropha digitiformis (Pohl) Steud., Manihot palmata var. digitiformis (Pohl) Müll.Arg., Manihot palmata var. diffusa (Pohl) Müll.Arg., Jatropha paniculata Pax ex Ruiz & Pav., Jatropha loureirii Steud. & Pohl

  • Description

    Description - Tropical shrubs, 1 to 4 m tall; all parts of plant with varying concentrations of a cyanogenic glucoside. Roots from seed a tap root, with secondary roots generally slender; adventitious roots arising from stem cuttings tuberous, variously shaped, from long and slender to globose. Stems woody, glabrous, or sparsely pubescent, except at the heavily pubescent apex, variously branched, from low, many-branched plants to tall and essentially unbranched; pith usually massive; leaf and stipule scars usually raised, sometimes not raised; predominantly brown, but sometimes yellow or silver. Leaves simple, frequently of two forms, either palmately lobed or nonlobed, the former predominant, the latter mostly associated with the inflorescence. Leaf lobes (2-)3-10(-12), linear, obovate or pandurate. The upper and lower lamina surfaces slightly pubescent between the veins, slightly to heavily pubescent on major veins; abaxial surface of lamina with a farinose layer, generally in a hexagonal pattern about the stomata; margins entire or slightly sinuate; stipules caducous, linear or laciniate; petioles from 5 to 25 cm long, frequently slightly S-shaped, attached basally to the lamina or slightly peltate, glabrous or slightly pubescent at base, and frequently a tuft of hairs at apex; leaves associated with inflorescence generally smaller, frequently 3-lobed, or sometimes simple, entire; lamina generally dark green, sometimes with red veins; petioles green, yellow-green, red or mixed red and green; young foliage at stem apices green, bluish green to dark red, very heavily pubescent. Inflorescence a panicle, generally from 2 to 10 cm long, glabrous; bracts and bracteoles strap-shaped, generally inconspicuous and caducous. Flowers monoecious, the pistillate basal, opening first, the staminate apical, opening later. Pistillate flower hypogynous; perianth of 5 separate, strap-shaped tepals, red, green or purplish, pubescent along inner margins, and frequently with a tuft of hairs at the interior apex; ovary subtended by a nonlobed disc, 3 carpellate, glabrous, style short, with 3 finely dissected stigmas. Staminate flower with a 5 lobed perianth of tepals united about half the length, glabrous externally, pubescent internally; stamens usually 10 (infrequently 8) in 2 whorls, 5 short and 5 longer, the filaments slender, glabrous, arising between the lobes of the basal disc, supporting versatile anthers; pollen 3-colpate, large, sticky, with spine-covered exine, in some cultivars sterile. Fruit a schizocarp, usually winged, but sometimes smooth-surfaced; dehiscence septicidal and loculicidal, leaving a central stalk. Seeds carunculate, elongate or rounded, variously marked, mottled brown and light brown, or plain.

    Description - Detailed Cultivar Description: Surface of tuberous roots most frequently rough but often smooth. External root color most frequently brown, dark brown or reddish brown but often light brown, tan or light tan, seldom light brown-yellow, pinkish white, light pink or pink or pinkish brown or pinkish tan. Root flesh usually white to cream, sometimes cream-yellow or yellow, rarely with some pink intermixed. Stems commonly brown, but often silver, sometimes yellow, seldom silver-brown. Storey length usually 9 to 20 cm, but sometimes short, 4-8 cm or long, 21-28 cm. Scars on stem usually either slightly raised or moderately raised, sometimes very large, seldom not raised (stem smooth). Stems most frequently more than two-branched, but commonly with one or two branches (excluding any branches at the top), less frequently unbranched, or a single branch at the top. Leaves with basic number of lobes odd, but occasionally with an even number of lobes; most frequently 7 or 8 lobed, sometimes 9 or 10 lobed, occasionally 5 or 6 lobed, rarely 3 or 4 lobed, or variable, 3, 4, and 5 lobed, or 4, 5, or 6 lobed. Leaf lobe shape prevalently obovate but sometimes linear; margins of obovate leaves usually simple, sometimes sinuous and rarely pandurate, of linear-shaped lobes, margins commonly sinuous, occasionally simple, rarely pandurate. Length of median lobe most frequently long, greater than 17 cm, often of moderate length, 14 to 17 cm and occasionally short, less than 14 cm. Width of median lobe predominantly moderate, 2.6 cm to 4.8 cm, sometimes narrow, 1.5 cm to 2.4 cm, or wide, 5 cm or more. Petioles mostly green, frequently red, occasionally reddish green, seldom greenish red. Young foliage most frequently green, often reddish blue, sometimes bluish green.

    Distribution and Ecology - Manihot esculenta, as a cultigen, is cultivated in all tropical countries of the world. The species is not known in a purely wild state. The limitations upon its growth are largely those of low temperature. In some subtropical areas, the cultigen is raised where there are a few periods of frost, but in these areas, the crop is of little economic significance. For this reason, we have cited only specimens which were selected to indicate the range of variability within the species. The collections made by Rogers form a part of the monographic study of the species, published separately (Rogers and Fleming, 1973), and all are deposited in the herbarium of the National Arboretum, Washington, D.C. An outline of the classification of the subspecific "groups" is given at the end of this section. (Table II). Other specimens cited are those confined to the Western Hemisphere, and were chosen because they represent the more important variations within the species. The crop is American in origin, and specimens from other areas of the world do not vary significantly from those we have selected.

  • Discussion

    All these [common names] may be modified by adding the equivalent of "bitter" (poisonous) or "sweet" (nonpoisonous) to the major name. In Brasil, aipim or macachiera may be used rather than "sweet" to differentiate those cultivars used as a fresh vegetable. All these names (or some equivalent sound) seem to have been in use by natives in the Western Hemisphere tropics, and may apply either to the plant or to one of its useful products. For example, cassava (or Cassabe) generally describes a large, dried cake made from the ground and dried root. Beju also refers to this product in Brasil.

    The major useful part of the plant is the starch-filled tuberous root, most often produced as an adventitious root from stem cuttings. However, in parts of Africa, particularly in the former Republic of the Congo (now designated Zaire), the foliage is eaten as a spinach with great regularity, and in considerable quantities. Use of the foliage is infrequent in the tropics of the Western Hemisphere.

    The roots may be used as a fresh vegetable, in a manner similar to use of the tubers of Solanum tuberosum, if the cultivar is known to produce roots with low concentrations of HCN. There are apparently no roots completely devoid of the poisonous substance, but in the “sweet” variations, most of the HCN is confined to the outer layer, or phelloderm. Those not entirely familiar with this cultigen would be well advised to treat all cultivars as poisonous, and to process them sufficiently to reduce the concentrations of HCN to tolerable levels.

    By far the largest food use of the roots follows a series of processes intended to remove the HCN (though recent evidence indicates that a trace of HCN remains after the best processing techniques), and perhaps to impart some desirable flavor to the product. In Brasil, the largest consumer of M. esculenta, much of the crop is produced as farinha, a dry meal eaten alone or in combination with many other foods. Gari, a product found in west Africa, is similar to Brasilian farinha. The number of variations on methods of preparation of the roots is almost endless. Frequently, a fermentation, or microbial conversion process, is employed in food production. Apparently, the flavors added by fermentation make the processed food more palatable. Tapioca is one of the best known of cassava products reaching the temperate zone markets.

    The starch from M. esculenta roots may be used in various industrial processes, such as paper sizing, in corrugated paper, or boxes, in many fillers where starches are important. Dried chips from the roots are imported into western Euorpean nations as part of cattle and hog rations.

    NOMENCLATURE. The nomenclatorial history of this species reflects, to some extent, the development of species concepts from their inception to the present. Linnaeus (1753) named the cultigen Jatropha Manihot. He did not accept Manihot as a separate or recognizable genus although European botanists used Manihot as a distinct taxon more or less equivalent to a genus for nearly 100 years before 1753. Linnaeus’ inclusion of the cultivated species in Jatropha caused considerable confusion in the literature until the monographic work of Pohl, who, in 1827, definitively described the genus and many other species of the genus. Although Pohl’s work was the definitive one, Miller, in 1754, is credited with the first post-Linnean application of the generic term. Miller intended to use an epithet first applied by Bauhin in 1651, M. theveti, but since he did not clearly espouse a strict binomial system (frequent polynomials) his species epithet is not permitted, and the name esculenta, first used by Crantz in 1766, becomes the first valid name for the cultivated species. Crantz’s name was not recognized, however, until Pax’s monograph in 1910, where the epithet was listed in synonymy under M. utilissima Pohl, and was not generally accepted until 1938, when Ciferri applied the modern concept wherein all the cultivars, with both high and low concentrations of the cyanogenic glucoside, are members of the same highly variable species.

    Many of the species epithets applied to M. esculenta are mere nomenclatorial synonyms, but several are here placed in synonymy for the first time, because we employ a broader concept of the species than any previous students. Thus, M. flabellifolia Pohl, M. digitiformis Pohl, M. diffusa Pohl, M. loureirii Pohl, M. melanobasis Muell.-Arg., M. sprucei Pax, and M. flexuosa Pax, all represent variations which fit well within our concept of this species. It is likely that each of the above species names is based upon materials collected from plants not consciously grown for their roots, but come from "volunteer" plants, apparently wild.

    We have placed all formal subspecific taxonomic designations of M. esculenta in synonymy because it is impossible to apply formal subspecific taxon epithets to fleeting variants which are not related to some precise geography or ecological region. In a monograph of the cultivars of M. esculenta (Rogers and Fleming, 1973), 19 informal "Groups" (see Intern. Code Nomen. Cult. PL, Utrecht, 1961) are recognized as clusters of similar morphologies, without relation to geographic distribution. The purpose of this grouping is to provide agricultural workers with guides for development of new or improved cultivars, and to document the morphological variation encompassed by the species, rather than for taxonomic naming of the variants. In our interpretation, Loureiro, Fl. Cochinchinensis 718, 1793, could only have seen Manihot esculenta, even though he cites as his authority Jacquin, who clearly described Manihot carthaginensis (Jacq.) Muell.-Arg. Loureiro indicates that the plants described were in cultivation, and we seriously doubt that Manihot carthaginensis had been imported into the Eastern Hemisphere tropics.

    BEGINNINGS OF CULTIVATION. This discussion is concerned with the earliest domestication of M. esculenta which is considered to be different from the botanical origin of the species. As evident from the computer analyses the closest wild relative of M. esculenta is M. aesculifolia (H.B.K.) Pohl. Some South American species are also related to a lesser extent (Fig 28), and thus the botanical evidence for the beginnings of cultivation are not yet sufficient to designate one area over another as the place where M. esculenta was first domesticated. In an earlier study, Rogers (1963) called attention to the possibility of a Meso American origin, as contrasted to other possible points of initial culture. Clearly, cultivation implies human activity, and the earliest such activity, with respect to documented archeological evidence, points to the Tehuacan Valley in the state of Puebla, Mexico (Callen, 1965). Other archeological records from Colombia (Reichel-Dolmatoff, 1956), Peru (Sauer, 1951), Tamaulipas, Mexico (MacNeish, 1958), merely indicate an early use of the species. We consider the point of initial cultivation to be a relatively unimportant problem, because the cultigen known today is a complex species with many points of initial cultivation. Wherever the species occurs (or has been transported by man), there is evidence (putative) that the plants have hybridized with other locally-occurring wild species, thus changing the genetic composition of the cultigen in such ways that the hybrid produced becomes a cultigen essentially unique to the region where the hybridization occurred. Since there are no apparent genetic barriers to hybridization within the genus Manihot, clearly a very complex species has developed and each hypothesis of origin or initiation of cultivation has some validity.

    An intriguing, but unsolved problem, is the origin of cultivars with little or no HCN versus those with relatively high concentration of the poisonous principle. Several suggestions have been made, apparently originating with Nordenskiöld (1924), that in the extreme western part of the distribution in South America there were no poisonous varieties, but to the east, both types were found. This seems to have no basis in fact. Both genetic and environmental influences play a role in the concentrations of HCN, but no studies have been sufficiently precise to determine the relative roles. The best studies to date of HCN in M, esculenta are those of DeBruijn (1971).

  • Common Names

    cassava, manioc, yuca, mandioca

  • Distribution

    Mexico North America| Tamaulipas Mexico North America| Santa Rosa Guatemala Central America| Honduras Central America| Atlántida Honduras Central America| Guatemala Central America| Jamaica South America| Colombia South America| Cundinamarca Colombia South America| Venezuela South America| Bolívar Venezuela South America| Guyana South America| Suriname South America| Peru South America| Huánuco Peru South America| Brazil South America| Amapá Brazil South America| Amazonas Brazil South America| Pará Brazil South America| Pernambuco Brazil South America| Goiás Brazil South America| Bahia Brazil South America| Bahia Brazil South America| Minas Gerais Brazil South America| São Paulo Brazil South America| Rio de Janeiro Brazil South America| Bolivia South America| La Paz Bolivia South America| Santa Cruz Bolivia South America| Paraguay South America|