Manihot esculenta |
Manihot davisiae |
|
---|---|---|
bitter cassava, cassava, manioc, tapioca |
Arizona manihot, pata de gallo |
|
Habit | Shrubs, 1–4 m. | Herbs or subshrubs, 1–3 m. |
Roots | thickened. |
thickened. |
Stems | erect, terete when young; nodes conspicuously swollen; leaf and stipule scars elevated, especially on older stems. |
erect, terete when young; nodes not swollen; leaf and stipule scars not elevated. |
Leaves | persistent; stipules lanceolate, entire; petiole 3–20 cm; blade basally attached, usually 3–10-lobed, sometimes unlobed, lobes without secondary lobes, median lobe 5–18 cm, margins neither thickened nor revolute, entire to ± repand, apex acuminate, surfaces glabrous or hairy, abaxial finely reticulate. |
stipules lanceolate, entire; petiole 2–9 cm; blade basally attached, 5–7-lobed, lobes with rounded secondary lobes distal to middle or with 2 pairs of rounded secondary lobes of nearly equal width proximal and distal to middle, median lobe 4–11 cm, margins neither thickened nor revolute, entire, apex acuminate, surfaces glabrous, abaxial smooth. |
Inflorescences | axillary, panicles, 2–10 cm. |
axillary, racemes, to 8 cm. |
Pedicels | staminate 2–4 mm; pistillate 20 mm in fruit, straight. |
staminate 4–9 mm; pistillate to 15 mm in fruit, downcurved. |
Staminate flowers | calyx campanulate, 10–15 mm, lobes erect or spreading; stamens 10. |
calyx campanulate, 7–15 mm, lobes erect or spreading; stamens 10. |
Capsules | 1.5 cm, usually winged. |
1.5 cm, nearly smooth, not winged. |
Seeds | subglobose to oblong, 12 mm. |
globose, 12 mm. |
2n | = 36. |
|
Manihot esculenta |
Manihot davisiae |
|
Phenology | Flowering year-round, mostly fall and winter. | Flowering Jul–Oct. |
Habitat | Disturbed areas, spreading from cultivation. | Desert scrub, thorn scrub, oak woodlands, oak grasslands. |
Elevation | 0–200 m. (0–700 ft.) | 100–2000 m. (300–6600 ft.) |
Distribution |
AL; FL; TX; South America (Brazil) [Introduced in North America; introduced widely in tropical and subtropical regions worldwide]
|
AZ; Mexico (Chihuahua, Sinaloa, Sonora) |
Discussion | The enlarged storage roots of Manihot esculenta yield a starchy staple, now much consumed in tropical regions around the world. Tapioca, a pelletized and partially hydrolyzed form of cassava starch, is the chief form of consumption in temperate regions. Multiple cultivars are known. These are generally characterized as bitter (containing cyanogenic glycosides, which must be removed before consumption) or sweet (cyanogenic glycosides absent or at low levels). A form with variegated leaves is sometimes grown for ornament. Cassava was cultivated throughout the Neotropics in pre-Columbian times. As a root crop with poor storage qualities adapted to humid regions, archeological remains are few, leading to much speculation in the literature about the origin of this important crop. Molecular data reported by K. Olsen and B. A. Schaal (1999, 2001), indicate that cultivated cassava constitutes M. esculenta subsp. esculenta, derived by artificial selection from its sole wild ancestor, M. esculenta subsp. flabellifolia (Pohl) Ciferri from the southern border of the Amazon basin. Under this classification, all North American plants belong to subsp. esculenta. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In the flora area, Manihot davisiae is limited to Pima and Santa Cruz counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 194. | FNA vol. 12, p. 194. |
Parent taxa | Euphorbiaceae > Manihot | Euphorbiaceae > Manihot |
Sibling taxa | ||
Name authority | Crantz: Inst. Rei Herb. 1: 167. (1766) | Croizat: J. Arnold Arbor. 23: 224. (1942) |
Web links |