Manihot Manihotoides (Euphorbiaceae) - CNCFlora

Systematic Position of the Genus 29
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.
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.
Fig 6A, B, C, D; 7A, B.
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).
DISTRIBUTION. 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. MEXICO. Tamauli-