328 PROCEEDINGS OF THE AMERICAN ACADEMY. 



cuneate base, thickish, glabrous and covered on both surfaces (under a 

 lens) with very numerous dark glandular dots; blade 8 to 10 cm. long, 

 2.3 to 3 cm. broad, pinnate-veined, the midnerve prominent beneath, 

 grooved above; petiole 1.8 cm. long; the upper axils proliferous: in- 

 florescence relatively small, 4 cm. broad, a trichotomous short-^jeduncled 

 corymb ; involucral bracts 5 to 6 mm. long, viscid-pubescent upon the 

 back, acutish : flowers 5 ; corolla, apparently white, about twice the 

 length of the involucre, the tube viscid-puberulent : achenes smooth or 

 nearly so, crowned with several narrow acute or subulate scales ; more 

 elongated awns apparently lacking. — Collected by C. & E. Seler in 

 mountain woods between St. Carlos and St. Bartolo, Yantepec, Oaxaca, 

 Mexico, 6 January, 1896, no. 1G95. Well marked. Ty^^es in herb. 

 Gray and herb. Royal Botanical Museum, Berlin. 



S. SKR^ATA, Cav., var. arguta. Leaves narrowly linear, ascending 

 or appressed, sharply serrate with incurved teeth : scales of the involucre 

 attenuate to a dark subulate tip. — Collected by C. G. Pringle on the 

 Cerro Ventoso above Pachuca, altitude 2,900 m., 18 August, 1898, no. 

 7652. 



S. tephra. Ashy throughout with a close pulverulent pubescence 

 not glandular: stems herbaceous, terete, purplish: leaves scattered, 

 elliptical, obtuse, crenate-serrate, 3 cm. long, half as broad, 3-nerved, 

 finely pubescent upon both surfaces, slightly paler beneath, mostly con- 

 duplicate along the midrib, gradually narrowed to a petiole (1 cm. in 

 length) ; fascicles of smaller leaves on short or scarcely developed axil- 

 lary shoots: inflorescence a moderately dense compound corymb; its 

 branches chiefly alternate, ascending, the lower and longer about 8 cm. 

 in length, the heads densely clustered at their summits ; individual pedi- 

 cels 1 to 2 mm. long; involucral scales merely acutish, cinereous- 

 puberulent, without evident glands, green or purplish-tinged, 4 to 5 mm. 

 long: flowers 5, about twice the length of the involucre: corolla-tube 

 purplish, puberulent ; limb white or nearly so : achenes black, lucid, 

 4 mm. long, minutely roughened upon the angles ; pappus of three awns 

 (equalling the corolla) and 3 short blunt intermediate scales. — Col- 

 lected by C. G. Pringle, Sierra de Pachuca, Hidalgo, altitude 2,925 m., 

 13 September, 1899, no. 8229. 



Piptothrix Goldmanii. Glabrous : stems terete, striate, purple, 

 slightly lucid; internodes 6 to 8 cm. long: branches opposite: leaves 

 deltoid-ovate, acuminate, serrate, 3-nerved fz'om the shortly cuneate base, 

 green and glabrous upon both surfaces, 8 to 10 cm. long, 6 to 8 cm. 

 broad, thin but firm in texture, reticulated veins slightly prominent upon 



