Manihot websterae Rogers & Appan
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Authority
Rogers, David J. & Appan, S. G. 1973. Manibot, Manihotoides (Euphorbiaceae). Fl. Neotrop. Monogr. 13: 1-272. 1 chart. (Published by NYBG Press)
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Family
Euphorbiaceae
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Scientific Name
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Type
TYPE. Webster, Miller & Miller 13074: Mexico, Puebla: 8 miles SE of Izucar de Matamoros, 18 Aug 1962 (holotype, DAV; isotype, PUL).
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Description
Latin Diagnosis - Arbores ca 5.0 m alti, pubescentes; folia penta vel septemloba lobis medianibus ca 11.0 cm longibus, ca 3.0 cm latibus; inflorescentia non visa; capsulae ca 2.25 cm longae; semina ca 1.5 cm longa.
Description - Trees, ca 5.0 m tall. Young stems light reddish brown, pubescent; mature stems dark reddish brown, pubescent. Leaves alternate; stipules deciduous, pubescent; petioles ca 10.0 cm long, terete, sometimes slightly canaliculate, pubescent; lamina nonpeltate, ventral surface green, sparsely pubescent, dorsal surface light green, sparsely pubescent, abaxial surface wax pattern smooth; venation camptodromous, midribs sparsely pubescent; palmately 5-7 lobed; median lobes ca 11.0 cm long, ca 3.0 cm wide, oblong-obovate, broadest ca 2/3 way up from the base, tapering into an acuminate apex, terminating in a bristle ca 0.75 cm long; lamina margin entire, base of lobe narrowly constricted, less than 0.25 cm across, sinuses between lobes very deep, lamina between the base of sinuses and petiole attachment point less than 0.5 cm wide; lowest lobes slightly smaller than, and more or less similar in shape, to median lobe. Inflorescence not seen. Fruit pedicels very short, less than 1.0 cm long, almost straight; capsules globose, ca 2.25 cm long from base to apex, surface glaucous green, slightly tuberculate, ribs not prominent, apex rounded; fruit dehiscence septicidal. Seeds oblong, ca 1.5 cm long, carunculate end acutely pointed, ventral side with a prominent ridge along the middle, surface not shiny, occasionally verrucate, light brownish orange, with fine black mottlings, caruncle very small.
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Discussion
The single collection representing this species is very distinct from all the other taxa. Further field studies are needed to outline its geographic boundaries and ecological adaptations and limits. Plants of Manihot websterae should be looked for in the region between Matamoros and Colima. This species can be easily distinguished from its close relatives M. michaelis and M. caudata by its characteristic nonpeltate leaf, extremely constricted lobe bases, and the short fruit pedicel.
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Distribution
(Fig 25C). Known only from the type locality, alt 1500 m, on limestone soil.
Mexico North America| Puebla Mexico North America|