Manihot Manihotoides (Euphorbiaceae) - CNCFlora

Systematic Position of the Genus 37
10. Petiole attachment widely peltate (lamina base more than 0.5 cm wide); staminate
buds distinctly constricted in the middle; staminate tepal lobes only slightly reflexed
at anthesis; seed rotund; decumbent shrubs. 12. M. walkerae.
2. Manihot pringlei Watson, Proc. Am. Acad. 26: 148. 1894; Pax in Engler, Pflanzenreich
IV. 147(Heft 44): 45. 1910.
More or less erect, tall shrubs 3.0-4.0 m tall; dichotomously and trichotomously
branching. Roots numerous, prominently swollen, elongated, 0.5-1.0 m long, shallow;
epidermis relatively smooth, brown (5 YR 4/5),6 lenticels oriented along horizontal lines;
subepidermis light tan, somewhat yellowish; cortex whitish, soft, somewhat pulpy, with a
very weak smell of HCN. Young stems glabrous, greenish gray-brown; mature stems
glabrous, light gray, lenticels vertically oriented. Leaves alternate; stipules deciduous,
glabrous; petioles about 15.0 cm long, occasionally longer, terete, glabrous, greenish,
reddish (7.5 R 4/11) towards the base, lamina nonpeltate, ventral surface deep green,
glabrous, dorsal surface pale green, glabrous, abaxial surface wax pattern smooth;
venation camptodromous, veins on the ventral surface green, glabrous, on the dorsal
surface reddish (7.5 R 4/11), glabrous, palmately 7 or 9 lobed; median lobes
oblong-pandurate, rarely oblong, entire lobed, usually about 12.0 cm long, apex
acuminate, the base of the lobe very narrowly constricted, less than 0.25 cm across,
lamina between the base of sinus and petiole attachment point less than 0.5 cm wide;
lowest lobes about half as long as median lobes, more or less similar in shape to median
lobes. Inflorescence a monoecious, terminal, subspicate/corymbose raceme, about 30.0
cm in length, the lower half of the rachis usually devoid of flowers, all parts glabrous;
bracteoles prominently foliaceous, lanceolate, apex accuminate, often as long as 3.0 cm,
0.5 cm wide, margin laciniate, veins on dorsal and ventral surfaces purplish, bractlets
foliaceous, purplish veined, often as long as 2.0 cm, 0.3 cm wide. Pistillate flowers restricted
to the base of the upper half of the inflorescence, borne on long, straight, ascending
pedicels, held at an angle of ca 45? to the rachis, the lowermost pedicel often 5.0-7.0 cm
long, subsequent pedicels decreasing gradually in length towards the apical end of the
inflorescence, creating more or less a corymbose type of inflorescence, pistillate tepals ca
1.6 cm long, reddish (2.5 R 4/10) externally, greenish yellow (2.5 GY 9/8) internally,
cleft down to base into 5 lobes, lobes oblong lanceolate, tapering; disc very prominent,
fleshy; staminodes often present around the disc, pistil ca 0.7 cm long, ovary
ovate-ellipsoid, the trifid stigma moderately lobed and lobulate. Staminate flowers almost
tubular, slightly constricted in the middle, tepals ca 1.8 cm long, reddish (2.5 R 4/10)
externally, greenish yellow (2.5 GY 9/8) internally, cleft nearly 1/3 way down into 5
lobes, lobes not prominently reflexed at anthesis, disc yellowish (5 Y 9/9), 10 lobed,
stamens 10, in 2 whorls of 5 each, superior whorl ca 1.3 cm long, inferior whorl ca 1.2 cm
long. Fruit pedicels long, straight, ascending, 3.0-7.0 cm long; capsules ovate-ellipsoid ca
1.5 cm long from base to apex, disc at the base very prominent, stigma scar at the apex
distinctly pointed, fruit surface more or less smooth, perceptibly 6 ribbed, ribs very dark
maroon (2.5 R 3/7), greenish in between ribs; fruit dehiscence septicidal. Seeds oblong, ca
1.25 cm long, basal end gently curved inside, caruncle moderately prominent. Seedlings at
early stages have a characteristic swollen hypocotyl region. Fig 9B, C, D.
TYPE. Pringle 3558: Mexico, San Luis Potosi: Limestone hills, Las Canoas, 15 Jul
1890 (syntype, GH). We have not found Las Canoas on recent maps. Efforts to find the
type locality on a recent trip to Mexico were unsuccessful.
DISTRIBUTION. (Fig 9A) Mexico: Tamaulipas and San Luis Potosi, along the
6 Refer to discussion of color designation in Systematic Criteria.