534 PROCEEDINGS OF THE AMERICAN ACADEMY. 



I.e. 557; Briq. in Engl. & Prantl I.e. aS*. microphylla, Gray, Proc. 

 Am. Acad. xxi. 407, in part, not Benth. — Northern and central 

 Mexico, not clearly separable from S. microjihylla. Chihuahua, 100 

 km. south of Guadalupe y Calvo, alt. 2,300 to 2,620 m., Aug., 1898 

 {E. W. Nelson, no. 4812^); Batopilas, alt. 1,690 to 2,000 m., Oct. 1898 

 {E. A. Goldman, no. 212) : Coahuila, hillside, Saltillo, May, 1898 {Edw. 

 Palm-r, no. 161): Durango, by stream, Durango, Nov. 1896 {Edw. 

 Palmer, no. 844) ; near El Salto, July 12, 1898, and in the Sierra 

 Madre, 25 km. north of Guanacevi, alt. 2,300 to 2,620 m., Aug. 17, 1898 

 {E. W. Nelson, nos. 4557, 4755) : Zacatecas, hills of Zacatecas, Oct. 

 26, 1888 ( C. G. Priagle, no. 1764) ; in the Sierra Madre, Aug. 18, 1897, 

 and near Plateado, Sept. 4, 1897 (/. N. Rose, nos. 2402, 2804) : San 

 Luis Potosi, in the mountains about San Luis Potosi, 1876 {ScJiaffner, 

 no. 660), 1878 {Parry & Palmer, nos. 747, 748): Vera Cruz, Mt. 

 Orizaba, alt. 2,770 ra., Aug. 8, 1891 (Seaton, no. 260) : Hidalgo, Zima- 

 pan {Coulter, no. 1093) : Mexico, ledges and banks, Sierra de las 

 Cruces, Oct. 23, 1892, and Serrania de Ajusco, alt, 2,770 m., May 23, 

 1898 {G. G. Pringle, nos. 4298, 7548). 



2. Leaves pubescent beneath. 



O Shrubs. 



+ Leaves mostly less than 2 cm. long, 



139. S. MICROPHYLLA, HBK. 1. c. 295. Leaves rounded at tip, 

 slightly pubescent. — Benth. 1. c, ; Hemsl. 1. c. 561 ; Gray, 1. c, in part ; 

 Briq. 1. c. — Central and southern Mexico. San Luis Potosi, San 

 Miguelito, 1876 {Schaffner, no. 662) ; in market of San Luis Polosi, 

 1898 {Edw. Palmer, no. 640^-) : Mexico, Valley of Mexico {Schajfner, 

 no, 394); Toluca, Sept. 17, 1898 {E. W. D. Holway, no. 3136): 

 Oaxaca, Tehuacan, alt. 615 m., June 24, 1896 {C.Conzatti, no. 163). 



Var. CANESCENS, Gray, 1. c. Leaves and branchlets densely canes- 

 cent-pubescent. — Chihuahua, in shade of cliffs, hills near Chihuahua, 

 Oct. 1 7, 1885 ( G. G. Pringle, no. 637) : Zacatecas, hills near Zacate- 

 cas. Mar. 17, 1885 {C. G. Pringle, no. 239), alt. 2,460 m. Dec. 8, 1898 

 {O.C.Denm, no. 139). 



Var. WiSLiZENi, Gray, 1. c. 408. Puberulent : leaves narrowed to 

 acutish tips. — Chihuahua, Sierra Madre west of Chihuahua ( Wislizenus, 

 no. 152) ; north of Batopilas, 1885 {Edw. Palmer, no. 379). 



+ + Leaves larger. 

 X Leaves subsessile or short (3 mm.)-petioled. 



140. S. tricolor, Lemaire, 111. Hort. iii. Misc. 71, t. 120, & Fl. des 



