STANDLEY TREES AND SHRUBS OF MEXICO 1567 



11. Zexmeiiia fasciculata (DC.) Schultz Bip. in Seem. Bot. Vov. Herald 306 

 1856. 



Lipochaeta fasciculata DC. Prodr. 5: 610. 18.36. 



Sinaloa and Chihuahua to Tamaulipas, south to Jalisco and San Luis Potosi; 

 tj'pe from Tvila, Tamaulipas. 



Shrub; branches strigillose, glabrate; petioles mostly 1 to 2.2 em. long; blades 

 lanceolate to ovate, 6 to 14 cm. long, 1.5 to 6 cm. wide, acuminate, cuneate at 

 base, serrate, rough above, sparsely to densely hispidulous or strigose beneath; 

 heads small, usually numerous in umbelliform cymes, the pedicels strigose, 1 to 3 

 cm. long; involucre 5 to 6 mm. high, slightly graduate, the outer and middle 

 phyllaries lance-ovate or ovate, with acuminate or subacuminate, loose, herba- 

 ceous tips. 



12. Zexmenia ceanothifolia (Willd.) Schultz Bip. in Seem. Bot. Voy. Herald 

 305. 1856. 



Verbesina ceanothifolia Willd. Sp. PI. 3: 2225. 1804. 



Lipochaeta umbellata DC. Prodr. 5: 610. 1836. 



Jalisco and Guanajuato to Veracruz and Oaxaca; type from Acapulco, 

 Guerrero. 



Shrub 2 to 3.3 meters high; branches strigose, glabrate; petioles 3 to 12 mm. 

 long; blades ovate to lance-oblong, 6 to 11.5 cm. long, 2 to 5 cm. wide, acuminate, 

 cuneate at base, rough and rugose above, reticulate and strigillose to short-hispid 

 beneath; heads as in Z. fasciculata; involucre 5 to 7 mm. high, strongly graduate, 

 the phyllaries broadly ovate to oval, obtuse to merely acute or apiculate. 



13. Zexmenia gradata Blake, Contr. U. S. Nat. Herb. 22: 632. 1924. 

 Sinaloa; type from Lodiego. 



Shrub, up to 3 meters high; branches strigose or atrigillose; petioles 4 to 12 

 mm. long; blades ovate to oblong-elliptic, 7 to 12.5 cm. long, 2.3 to 5.3 cm. wide, 

 acuminate, at base cuneate to rounded-cuneate, rough above, beneath densely 

 and rather softly hirsute-pilose on all the veins and veinlets, sometimes also 

 between them, with usually spreading or divergent hairs; heads small, in umbelli- 

 form clusters, the pedicels strigillose, mostly 7 to 15 mm. long; involucre 6 to 7.5 

 mm. high, strongly graduate, the phyllaries ovate to broadly oval or suborbicu- 

 lar, obtuse to acute. 



14. Zexmenia rotundata Blake, Contr. U. S. Nat. Herb. 22: 632. 1924. 

 Known only from the tj^pe locality, Huasemote, Durango. 



Shrub; branchlets sparsely strigillose; petioles 6 to 8 mm. long; blades lance- 

 ovate, 5.5 to 8 cm. long, 2 to 2.8 cm. wide, acuminate, cuneate at base, sparsely 

 hirsute on both sides; heads small, in terminal umbelliform cymes of 3 to 6; 

 involucre 8 to 9 mm. high, strongly graduate, the phyllaries suborbicular to 

 oval, with rounded thin-herbaceous tips. 



15. Zexmenia microcephala Hemsl. Biol. Centr. Amer. Bot. 2: 173. 1881. 

 Lipochaeta umbellata conferta DC. Prodr. 5: 610. 1836. 



Zexmenia ceanothifolia conferta A. Gray; W. W. Jones, Proc. Amer. Acad. 41: 

 155. 1905. 



Tepic and Morelos; type from San Bias, Tepic. 



Shrub; branches strigose, glabrate; leaves subsessile, oblong or oval-elliptic 

 to ovate or lance-ovate, 3.5 to 10 cm. long, 1.5 to 3.8 cm. wide, acute, at base 

 rounded, smoothish above, strigillose beneath; heads numerous in close umbelli- 

 form cymes or cymose panicles, the pedicels strigillose, 1 to 2 cm. long; involucre 

 campanulate, 6 to 8 mm. high, graduate, the phyllaries oblong or oval, obtuse or 

 apiculate, or the outermost acute. 



16. Zexmenia cordifolia Blake, Contr. U. S. Nat. Herb. 22: 633. 1924. 

 Known only from the type locality, near Acaponeta, Tepic. 



57020—26 17 



