STANDLEY TEEES AND SHRUBS OF MEXICO 1591 



Taraaulipas to Chiapas. Guatemala to South America; type collected between 

 Caracas and Mount Buenavista, Venezuela. 



Suffrutescent or herbaceous, scandent; stem glabrous or pubescent; leaves 

 petioled, the divisions lanceolate to ovate, 2.5 to 9 cm. long, acute to attenuate, 

 closely serrate; heads usually numerous, cymose-panicled, slender-pediceled^ 

 4.5 cm. wide or less; achenes linear, ciliate, the 2 awns spreading or recurved,' 

 retrorse-hispid or smooth. "Flor de colmena" (El Salvador). 



81. COSMOS Cav. Icon. PL 1: 9. pi. I4. 1791. 

 Herbs, rarely suffrutescent; leaves opposite, entire to dissected; heads radiate, 

 purple, pink, white, or yellow; involucre double, as in Coreopsis; rays neutral; 

 achenes obcompressed or angulate, more or less distinctly rostrate; pappus of 

 2 to 9 retrorsely hispid awns. 



An herbaceous species of this genus is much cultivated as an ornamental plant 

 under the name "cosmos." 

 Rays purple. 

 Leaves narrowly linear and entire to bipinnatisect with linear divisions, 



these more than 1 mm. wide 1. C. crithmifolius. 



Leaves pinnatisect, the lobes linear-filiform, 0.7 mm. wide or less. 



2. C. seemannii. 

 Rays yellow 3. C. landii. 



1. Cosmos crithmifolius H. B. K. Nov. Gen. & Sp. 4: 242. 1820. 

 Bidens valladolidensis Schultz Bip. in Seem. Bot. Voy. Herald 308. 1856. 

 Sinaloa to Oaxaca; type from Valladohd (Morelia), Michoacdn. 

 Suffrutescent, 50 to 90 cm. high, slender, glabrmis; leaves 3.5 to 12 cm. long, 



narrowly linear (1.5 to 4 mm. wide) and entire, or pinnatisect to bipinnatisect, 

 rough-margined; heads few or solitary, long-peduncled, 2 to 4.5 cm. wide; disk 

 yellow; achenes linear-fusiform, angled; pappus of usually 4 awns. "Gallitos" 

 (Sinaloa) . 



2. Cosmos seemannii (Schultz Bip.) A. Gray, Proc. Amer. Acad. 19: 16. 



1883. 



Bidens seemannii Schultz Bip. in Seem. Bot. Voy. Herald 307. 1856. 



Tepic and Michoacdn; type from the Sierra Madre. 



Suffrutescent, about 60 cm. high, minutely hirtellous, leafy; leaves about 

 5 cm. long, twice or theice pinnatisect with very narrow divisions; heads 1 to 7, 

 long-peduncled, 2.5 to 4.5 cm. wide; disk corollas purplish on the teeth; awns 6 

 to 9. 



3. Cosmos landii Sherff, Bot. Gaz. 64: 29. 1917. 



Bidens palmeri A. Gray in S. Wats. Proc. Amer. Acad. 22: 429. 1887. Not 

 Cosmos palmeri Robinson, 1909. 



Jalisco; type from Rio Blanco. 



Suffrutescent, about 1 meter high, glabrous; leaves 4 to 6 cm. long, pinnat- 

 isect or bipinnatisect, the segments linear, 1 to 2 mm. wide, rough-margined; 

 heads several, long-peduncled, 2.3 to 3.8 cm. wide; flowers all yellow; achenes 

 rostrate; awns 2 to 4. 



82. CALEA L. Sp. PI. ed. 2. 1179. 1763. 



Reference: Robinson & Greenman, Revision of the Mexican and Central 

 American species of the genus Calea, Proc. Amer. Acad. 32: 20-30. 1896. 



Shrubs or sometimes herbs; leaves opposite; heads radiate or discoid, yellow 

 or white, usually cymose; involucre several-seriate, graduate, the phyllaries dry 

 or the outer sometimes herbaceous; rays if present fertile; achenes subterete or 

 4 or 5-angled; pappus persistent, of 4 to 20 usually equal, paleaceous squamellae 

 or awns, rarelv entirely wanting. 



