578 PROCEEDINGS OF THE AMERICAN ACADEMY. 



and pedicels tomentulose ; bracts linear, setaceous ; heads about 1 cm. 

 high, 5-6-flowered ; scales of the involucre 5 to 6, oblong-oblanceolate, 

 8 mm. long, 2 to 3 mm. wide, obtuse and slightly pubescent at the apex, 

 otherwise glabrous ; margins thin, subscarious : pappus somewhat tawny, 

 about 5 mm. long ; corolla glabrous : achenes pubescent. — Collected by 

 C. G. Pringle along streams on the Sierra de Pachuca, State of Hidalgo, 

 altitude 2,700 m., 17 July, 1898, no. 6917. 



A species having its affinity with C. tussilaginoldes, HBK., and 

 C. mnidifolia, DC. From the former it is distinguished by the outline 

 and general character of the leaves, and from the latter by the white 

 tomentum on the lower surface of the leaves, and the pubescent achenes. 



Lactuca brachyrrhyncha. An erect herbaceous annual : stems 1 m. 

 or more high, glabrous or nearly so^ purplish : leaves lance-attenuate, 

 1 to 1.3 dm. long, about 1 cm. broad, acute, entire or remotely denticu- 

 late, sessile by a clasping sagittate base, glabrous upon either surface or 

 bearing on the midrib beneath, especially towards the base, scattered 

 rather long hairs, these often continuing with the subdecurrent midrib 

 to the stem, the upper leaves gradually reduced: inflorescence in a 

 terminal panicle; peduncles bracteate ; heads 1.2 to 1.5 cm. high, about 

 20-flowered ; involucral bracts imbricated, more or less deeply colored 

 with purple, the outer short, ovate, acutish, the inner lance-linear: flow- 

 ers blue : pappus white : achenes oblong-elliptic, 4 mm. long, one half as 

 broad, abruptly contracted at the summit into a short beak less than 

 1 mm. in length. — Collected by C. G. Pringle at Tlalnepantla, Valley 

 of Mexico, Federal District, 6 July, 1898, no. 6883. 



A species habitally like L. inteffrifolia, Bigel., from which it is readily 

 distinguished by the short yet distinct beak of the achenes. 



