APRIL, 1904. PLANTS YUCATAN^ MILLSPAUGH & CHASE. 141 



mon in open places near Izamal Sept. to Jan." Gaumer 304, San 

 Anselmo 1584, Calotmul 1586, Chichankanab 1672. 



Called by the Yucatecans "CARDO SANTO DEL MONTE." 



POROPHYLLUM Vaill. ex L. Hort. CM., 494. 



Heads homogamous, discoid, flowers perfect, fertile, tubular. 



Involucre cylindrical or narrowly campanulate of herbaceous, equal 



bracts in i series, free or connate at the base. Receptacle small, 



naked. Achene dorsally compressed, linear, many striate; pappus of 



copious slender, bristles in 1-2 series. Herbs or small shrubs with 

 conspicuously punctate leaves and involucres. 



Achene broadest in the middle, unribbed macrocephalum. 



lower third, slightly ribbed Millspattghii. 



Porophyllum macrocephalum DC. Prod., 5:648. 



An erect, glabrous annual, branching above, with terete, striate 



stem and branches, and opposite, slender petioled, broadly elliptic, 



coarsely crenate leaves, a pellucid gland 

 at the apex and subtending each sinus, 

 and a few irregularly disposed on the leaf 

 surface. Inflorescence of solitary, term- 

 inal, and axillary heads on upwardly 

 thickened peduncles. Heads 25 mm. 

 high, 12 mm. broad, 40-50 flowered. 

 Involucre cylindrical, bracts distinct, 

 narrowly oblong, abruptly acute, scarious 

 margined; glands dark, linear, biseriate. 

 Corolla greenish, 5 lobed. Receptacle 

 convex, pitted, fimbrillate. Achene dark 

 brown, .7x12 mm., linear oblong, 

 slightly tapering at either end; in sec- 

 tion elliptical; upwardly hispid, the hairs 

 longer and denser toward the summit, 

 finely striate, or the striations obsolete at 



maturity; pappus brown, 8 mm. long, hispidulous. 

 Hab. Izamal, Gaumer 2510. 

 Our specimens have peduncles less conspicuously thickened than 



usual in this species. 



Porophyllum Millspaughii Robinson, Field Col. Mus. Bot., 2:109. 



Shrub* or undershrub; stems and primary branches terete, covered 

 with a purplish gray smoothish cortex',, widely and dichotomously forked 

 (through the habitual tendency to abortion in the terminal bud); leaves ellip- 

 tical, rounded at both ends, coarsely crenate through the intrusion on each 

 edge 0/2 or j shallow bays, membranaceous, thin, not paler beneath, 2.2 to 

 J.J cm. long, 1.4 to 1.8 cm. broad; glands intramarginal, the lateral 

 lunate, subtending the bays, the terminal one linear, coincident with the 

 apex of the midnerve, other glands upon the surface of the leaf wholly 



*Original description and notes in italics. 



