174 PROCEEDINGS OP THE AMERICAN ACADEMY 



rate, acute at the apex, obtusish at the base, more or less distinctly 

 3-nerved, pubescent above, canescent-tomentose over the whole sur- 

 face beneath, 1|— 2 inches long, 7-9 lines broad: petioles short, 

 pubescent; bracts of the loose corymbose inflorescence small, lance- 

 linear, 3-4 lines long: heads about a dozen, including rays 6-8 

 inches in diameter; scales of the involucre ovate, acute, the outer 

 somewhat shorter, the inner longer, narrower, more oblong and 

 mure acute, but scarcely acuminate : rays about 10, white, tube 

 hirsute-pubescent, ligula broadly elliptic, 3-toothed, 3 lines long: 

 disk flowers yellowish white (?), tube hirsute-pubescent, limb 5- 

 toothed: anthers entire at the base: style tips with short blunt 

 appendages: achenes small, black, oblanceolate in outline, hispid- 

 ulous : pappus none. — Mountains near Patzcuaro, Michoacan, 

 November, 1891 (n. 4099). Distinguished from S. Liebmanni, 

 Scbultz Bip. ex char.,* by having heads loosely coiymbose, not 

 solitary, leaves ovate-lanceolate not elliptic, tomentose over whole 

 surface beneath instead of along the nerves. 



Gymnolomia canescens. Stem striate-furrowed, branched, 

 leafy below, nearly leafless above, clothed with a close gray 

 more or less deciduous pubescence, and sparingly villous : leaves 

 opposite, ovate, subcordate, entire, acute or obtuse, triply nerved, 

 2-3^- inches long, roughish-pubescent above, canescent beneath 

 with silky appressed hairs; petioles 6-8 lines long: inflorescence 

 of several slender naked branches, each bearing 1-8 rather closely 

 aggregated heads (4-5 lines in diameter) : pedicels and bracts of 

 the involucre canescent, the latter lanceolate, acuminate, rather 

 loosely imbricated in 2-3 series, the outer somewhat shorter: 

 rays 5-7, yellow, not exceeding the disk: chaff ovate-lanceolate, 

 carinate, terminating in acute pubescent points, with or without 

 lateral teeth: style branches of the disk flowers with rather at- 

 tenuated tips: achenes dark, mottled with light color: pappus 

 none. — Brackish marsh, Las Tablas, San Luis Potosi, June, 1890 

 (n. 3611), and alkaline plains, Hacienda de Angostura, San Luis 

 Potosi, June, 1891 (n. 3763). This species differs from the other 

 Gymnolomias which I have examined, in having more attenu- 

 ated style tips, but it appears better placed in this genus than 

 elsewhere. 



Tithonia brachypappa. Stem terete, striate, smooth or nearly 

 so, branched above : branches terminating in peduncles thickened 



* Klatt in Leopoldina, XXIII. 2. 



