FERNALD. — MEXICAN SOLANUMS. 557 



II. — A REVISION OF THE MEXICAN AND CENTRAL 

 AMERICAN SOLANUMS OF THE SUBSECTION 



TORVARIA. 



Dunal's subsection Turvaria of the genus Solanum has never been 

 unilerstood in America. Almost without exception the many diverse 

 forms from equally diverse regions have been in American herbaria 

 placed under the type species Solanum torvum, Swartz. This treatment 

 as a single polymorphous species of all the plants of similar subgeneric 

 character, — a course by no means without precedent in other sections 

 of Sulanuni and scores of other tropical American genera, — has been 

 due to a lack of authentic material and of any more concise statement of 

 the specific characters than can be found in the rather ponderous mono- 

 graph of Dunal. An accumulation of specimens from many sources has 

 made it possible to divide the Mexican material passing in the Gray 

 Herbarium as Solanum torvum into species of marked morphological 

 characters and restricted geographical ranges. Most of these plants 

 thus separated are found to agree very well with the descriptions of 

 different species recognized from Mexico by Dunal in his monograph, 

 though three species there characterized have not yet been identified with 

 modern herbarium material. Doubtless these identifications of modern 

 Mexican specimens with the old descriptions cannot all be taken as 

 final, and a study of the type specimens, when it is possible to examine 

 them, may prove the present conclusions to be in some cases inaccurate. 

 Yet confidence is felt that the present understanding of the group is 

 much clearer than that which has prevailed among recent students of 

 JNIexican botany. With the hope of simplifying the future study of the 

 group the following synopsis is presented of the Mexican species of the 

 section as now interpreted. 



* Pubescence of flowerin;? branches densely stellate-tomentose, hairs sliort and 



fine. 



+- Pedicels bearing simple gland-tipped liairs among the stellate ones. (See also 



S. ochraceo-ferrugineum.) 



S. TORVUM, Swartz. Branches slightly armed, canescent-ochraceous, 

 the young parts, especially, ochraceous : leaves subcordate-ovate, shal- 

 lowly sinuate-lobed, olive-green and stellate-scabrous above, canescent 

 and stellate-tomentose beneath, 1 to 1.5 dm. long, 6 to 12 cm. broad, 

 often sparingly armed on the midrib beneath, more rarely so above : 



