Manihot Manihotoides (Euphorbiaceae) - CNCFlora

Systematic Position of the Genus 39
southern and southwestern slopes of Sierra de Tamaulipas and the eastern slopes of Sierra
Madre Oriental, in a more or less crescent-shaped area bordering the plains surrounding
Tampico, at 300-2000 m. Growing in dense woods (Crutchfield & Johnston s n) and
amidst dry scrub vegetation (Webster 11229), invariably in limestone-based soil. Rogers,
Appan & Rogers 528 was colonizing a disturbed habitat on unconsolidated sandy red
lateritic soil dumped after road construction in a mixed broad leaf oak forest with Dioon
edule, Croton sp., Solanum shrubs and scattered palms. This ability to colonize disturbed
habitats is manifested by most of the species of Manihot. MEXICO. Tamaulipas: Crutchfield
& Johnston s n (TEX) 3 miles SE of Gomas Farias, 26 Sep 1960; Dressier 1913 (MO) Sierra de
Tamaulipas, Rancho las Yucas, 20 Jul 1957; Palmer 266 (F-2, NY, UC, US-3) Vicinity of Victoria,
Feb-Mar 1907; Reiche 1072 (M) S. Victoria, Sep 1926; Rogers, Appan & Rogers 528 (COLO-2, F-3,
G-3, K-2, M-2, MEXU, MICH-2, MO-2, NY-4, US-3, W-2) 13.5 miles SW of Ciudad Victoria on Road to
Juamave, 21 Jun 1968; Webster 11229 (DAV) 15 miles SW of Ciudad Victoria, 9 Jun 1962. San Luis
Potosi: Kenoyer A-198 (F, MICH) Valles 3 Sep 1938; Pringle 3826 (A, F, MICH-2, MO, NY, UC,
US-2, W) Lime Stone Hills, Las Canoas, 14 Aug 1891; Purpus 5465 (F, MO, NY, UC) Minas de San
Rafael, May 1911. Province Unknown/Uncertain: Collector Unknown/Uncertain (MO).
The roots of M. pringlei seem to contain very little HCN. The authors' collecting
experience indicated almost no odor when the fresh roots (Rogers, Appan & Rogers, 528)
were dug. Since these plants are found in the same general region and same general
habitat as the caves reported in archeological digs by MacNeish (1958), where seeds of M.
dulcis (=M. esculenta) were found, this species may have contributed some genetic
material to the cultivated complex. The structure of its inflorescence and the size of the
flowers differentiate M. pringlei very well from all other species in Mexico.
Cuttings and seeds of this species have been grown successfully
at the Fairchild
Tropical Gardens, Miami, Florida. Reports that this species had been introduced into
Madagascar are apparently unfounded.
3. Manihot auriculata McVaugh, Brittonia 13: 190. 1961.
Arborescent shrubs/low trees, ca 6.0 m tall, diam at base ca 6.0 cm, with long weak
trailing branches. Stems glabrous, grayish brown. Leaves alternate; stipules deciduous,
glabrous; petioles 15.0-20.0 cm long, terete, glabrous; lamina nonpeltate, dorsal and
ventral lamina surfaces glabrous, abaxial surface wax pattern smooth; venation camptodromous,
midribs glabrous; palmately 5 lobed, 3 major and 2 slightly smaller lobes;
median lobes oblong, ca 14.0 cm long and ca 5.0 cm wide, margin broadly sinuate, apex
acuminate; lowest lobes ca half as long as median lobes, slightly reflexed downwards.
Inflorescence a long raceme, monoecious, ca 15.0 cm in length, all parts glabrous;
bracteoles setaceous, margin smooth; bractlets setaceous. Pistillate flowers restricted to
the base of the inflorescence, borne on short (ca 1.0 cm long) pedicels, tepals and pistils
not seen. Staminate buds ovoid-ellipsoid, tepals pale yellowish, ca 1.7 cm long, 5 lobed,
lobes auriculate at sinus, disc 10 lobed; stamens 10, in 2 whorls of 5 each, longer ones ca
1.3 cm in length, shorter ones ca 0.8 cm, anthers 0.30-0.35 cm long. Fruits and seeds non
vidi. Fig 10B, C.
TYPE. McVaugh 15283: Mexico, Nayarit: Mirador del Aguila, ca 14 miles N of Tepic
10 Jul 1957 (holotype, MICH).
DISTRIBUTION. (Fig 10A). Mexico, Nayarit, western slopes of Sierra Madre
Occidental, alt ca 500 m. Lower forested slopes of steep, rocky ravine.
This species is characterized by its unique auriculate staminate tepal, a feature not
occurring in any other Manibot species.
4. Manihot aesculifolia (Humbolt, Bonpland & Kunth) Pohl, P1. Bras. Ic. et Descr. 1: 55.
1827; Muell.-Arg. in DC., Prodr. 15(2): 1065. 1866; Pax in Engler, Pflanzenreich IV.
147(Heft 44): 58. 1910; Standley, Contr. U. S. Nat. Herb. 23: 645. 1923; Croizat,
Jour. Arnold Arbr. 23: 218. 1942.