458 PROCEEDINGS OF THE AMERICAN ACADEMY. 



hirtellous: inflorescence cymose-paniculate : corolla white or purplish, 

 campanulate ; lobes revolute, externally pubescent : fruit covered with 

 rather short uncinate-hispid bristles. — Nov. Gen. & Spec. iii. 337 ; Hems). 

 Biol. Cent.-Am, Bot. ii. 65. — Guanajuato, Duges ; Valley of Mexico, 

 Pringle, no. 6518; Jalisco, Rio Blanco, Palmer (collection of 1886), no. 

 753 ; Tepic, near Santa Teresa, Rose, no. 2151 : Orizaba, Seafon, no. 

 127. A specimen from Culiacaii, Palmer (collection of 1891), no. 2777, 

 may be doubtfully referred here. 



"Var. glabratum, Nearly glabrous throughout, otherwise as in the 

 typical form. — Collected by E. W. Nelson on the west slope of Mt. 

 Zempoaltepec, Oaxaca, altitude 2370 to 2460 m., 5 to 13 July, 1894, 

 no. 583. 



Var. platyphyllum. Similar to the species proper, but with 

 broader oblanceolate or oblong-spatulate leaves, 1 to 2 cm. long, 2 to 

 6 mm. wide, abruptly cuspidate-acuminate at the rounded summit, not 

 nnfrequently hirtellous-puberulent beneath and occasionally hirsutish 

 above. — Chiapas, near Christobal, altitude 2150 to 2704 m., 18 Sep- 

 tember, 1895, E. W. Nelson, nos. 3165, 3200; Oaxaca, Sierra de San 

 Felipe, altitude 3075 m., 28 June, 1894, Pringle, no. 5663; vicinity of 

 Yolontepec, altitude 1700 to 2150, 15 to 20 July, 1894, Nelson, no. 714; 

 Colima, 9 January to 6 February, 1891, Palmer^ no. 1407. 



* * Leaves in whorls of four : tlie angles of tlie stem aculeolate-hispidulous : 



flowers cymose. 



4. G-. prsetermissum, Greenji. Stems slender, 3 to 4 dm. long, 

 ascending from a perennial base, slightly hispidulous : leaves linear-lan- 

 ceolate to linear, 8 to 14 mm. long, 1 to 3 mm. broad, acute, margins revo- 

 lute, upper surface often slightly hispidulous, the lower glabrous : flowers 

 terminating the lateral branches in subtrichotomous cymes. — Proc. Am. 

 Acad, xxxii. 306. — Federal District, Pringle^ no. 6596. 



* * * Leaves in fours : hirsute-pubescent to nearly glabrous plants, not retrorsely 



aculeolate-hispid : flowers terminating the stems and branches in rather close, 

 or dichotomously branching cymes. 



•1- Flowers paniculately disposed in dichotomously branching leafy cymes : unci- 

 nate bristles of the fruit subappressed. 



5. G. Pringlei. Stems 3 to 5 dm. high, erect or iiscending from a 

 perennial base, covered with a spreading hirsute pubescence: leaves in 

 fours, the uppermost opposite, 1-nerved, oblong-elliptic to oblong-lanceo- 

 late, 4 to -1 2 mm. long, 1 to 5 mm. broad, submucronate, narrowed at the 

 base, hirsute-pubescent upon either surface : flowers sessile or short- 

 pedicelled : corolla whitish : fruit about 1.5 mm. in breadth, covered with 



