642 CONTRIBUTIONS FROM THE NATIONAL. HERBARIUM. 



32. Jatropha rufescens T. S. Erandeg. Uiiiv. Calif. Pobl. Dot. 4: 88. 1910. 

 Known only from the type locality, Tlacuilotepec, Puebla, altitude 1,800 



to 2,100 meters. 



Branches thick and succulent ; leaves 6 to 10 cm. wide, shallow-lobate or 

 merely undulate, cordate at base, bright green on the upper surface, covered 

 beneath witli a dense brownish tomentum. 



33. Jatropha pseudocurcas Muell. Arg. Linnaea 34: 208. 1865. 

 Jalisco to Oaxaca ; type from Oaxaca. 



Shrub, 3 to 4.5 meters high ; leaves 10 to 20 cm. wide, broadly cordate at 

 the base, copiously pubescent ; capsule 2.5 cm. long. 



DOUBTFUL SPECIES. 

 The following, described from Mexico by Cervantes in 1794 (Supl. Gac. Lit. 

 Mex. 3, 4), are so imperfectly characterized that their identification is alto- 

 gether doubtful : J. ciliata, J. eduUs, J. octanclra, J. pahnata, J. quinqtieloba, 

 J. triloba. 



19. MANIHOT Adans. Fam. PI. 2 : 356. 1703. 



Reference: Pax in Engl. Pflanzenreicli IV. 147": 21-99. 1910. 

 Shrubs or trees, or sometimes lierbs, usually with succulent stems, often 

 glaucescent ; leaves alternate, petiolate, usually large and lobate ; flowers large, 

 monoecious, apetalous, racemose or paniculate ; fruit a capsule. 



Manihot glaziovii Muell. Arg. is the Ceara rubber tree, an important rubber 

 plant of Brazil. 

 Bracts of the inflorescence large and foliaceous. 



Lobes of the leaves shallowly lobate 1. M. pring'lei. 



Lobes of the leaves entire. 



Calyx glabrous outside 2. M.crassisepala. 



Calyx pubescent 3. M. foetida. 



Bracts small and inconspicuous. 

 Lobes of the leaves lobate. 

 Lobes of the leaves linear or lance-linear, broadest below the middle. 



4. M. angustiloba. 

 Lobes of the leaves broad, dilated at apex. 



Cal3^x 1 cm. long; bractlets usually absent 5. M. carthaginensis. 



Calyx 1.5 cm. long ; bractlets of the pedicels linear, 5 to 10 mm. long. 



6. M. interm^edia, 

 Lobes of the leaves entire. 



Bracts incised-laciniate 7. M. microcarpa. 



Bracts entire. 



Calyx pubescent v/ithin, glabrous outside. 



Anthers very short ; ovary 6-angulate ; capsule winged_8. M. esculenta. 



Anthers elongate; ovary terete; capsule not winged 9. M. dulcis. 



Calyx glabrous throughout. 



Leaves 3-parted. the lobes truncate or emarginate 10. M. pauciflora. 



Leaves 3 to 7-lobed or parted, the lobes acutish to acuminate. 



Lobes of the leaves lanceolate 11. M. olfersiana. 



Lobes of the leaves rhombic or obovate. 



Lobes rhombic, abruptly dilated above 12. M. rhomboidea. 



Lobes obovate, not abruptly dilated. 



Lobes abruptly cuspidate-acuminate 13. M. caudata. 



Lobes merely acuminate 14. M. aesculifolia. 



I 



