STANDLEY TREES AND SHRUBS OF MEXICO 1423 



Fruticose, decumbent, cespitose, the branches up to 60 cm. long, very leafy; 

 leaves subsessile or short-petioled, the blades eUiptic, 8 to 20 mm. long, 2 to 10 mm. 

 wide; heads crowded, white, about 7 mm. high. 



2. Oxylobus glanduliferus (Schultz Bip.) A. Gray; Klatt, Leopoldina 20: 75. 



1884. 

 Ageratum gland ulifer urn Schultz Bip.; Hemsl. Biol. Centr. Amer. Bot. 2: 82. 



1881. 

 Carelia glandulifera Kuntze, Rev. Gen. PL 1: 325. 1891. 

 High mountains of Oaxaca; type from Mount Zempoaltepec. 

 Frutescent, up to 1.3 meters high, leafy; leaf blades oval or oval-ovate, 2 to 

 3.5 cm. long, 10 to 18 mm. wide, crenate, the lower petioled; heads white or bluish, 

 7 to 8 mm. high. 



3. Oxylobus adscendens (Schultz Bip.) Robins. & Greenm. Proc. Amer. Acad. 



41: 272. 1905. 



Ageratum adscendens Schultz Bip.; Hemsl. Biol. Centr. Amer. Bot. 2: 80. 1881. 



Carelia adscendens Kuntze, Rev. Gen. PI. 1: 325. 1891. 



High mountains of Puebla, Hidalgo, and State of Mexico; type from Mount 

 Orizaba. , 



Scarcely frutescent, creeping and leafy at base; stem herbaceous, up to 50 cm. 

 high, bearing 3 or 4 remote pairs of leaves; leaf blades obovate or spatulate- 

 obovate, 2 to 4 cm. long, 1 to 2 cm. wide, crenulate, narrowed into a shorter 

 petiole; heads crowded at tip of stem, about 8 mm. high. 



11. AQERATELLA A. Gray in S. Wats. Proc. Amer. Acad. 22: 419. 1887. 



Reference: Robinson, Proc. Amer. Acad. 41: 271. 1905. 



Frutescent or suffrutescent, with slender stems and alternate or opposite leaves; 

 heads numerous, small or medium, somewhat racemose-paniculate; involucre 

 strongly graduated, the dryish scarious-margined phyllaries more or less in 5 

 vertical ranks; receptacle naked; achenes 5-angled; pappus of 5 scarious lance- 

 ovate squamellae prolonged into hispidulous bristles much longer than the achene. 



The genus contains only two species. 

 Leaves opposite, broadly ovate, rhombic-ovate, or obovate. .1. A. microphylla. 

 Leaves alternate, linear to linear-oblanceolate 2. A. palmeri. 



1. Ageratella microphylla (Schultz Bip.) A. Gray in S. Wats. Proc. Amer. 



Acad. 22: 419. 1887. 

 Ageratum microphyllum Schultz Bip. in Seem. Bot. Voy. Herald 298. 1856. 

 Decachaeta seemanni Benth. & Hook. Gen. PI. 2: 239. 1873; Hemsl. Biol. 



Centr. Amer. Bot. 2: 78. pi. 1,2. 1881. 

 Ageratella microphylla seemanni A. Gray in S. Wats. Proc. Amer. Acad. 22: 



419. 1887. 

 Sinaloa (?) and Jalisco; type from the Sierra Madre of northwestern Mexico. 

 Shrubby, about 30 cm. high, much branched; leaves mostly opposite, short- 

 petioled, the blades broadly ovate to rhombic or obovate, 6 to 12 mm. long, 

 4 to 7 mm. wide, crenate-serrate, veiny, finely puberulous and gland-dotted; 

 heads clustered in the axils and toward tip of stem, cylindric, S mm. high, forming 

 a very narrow, loosely spicate panicle. 



2. Ageratella palmeri (A. Gray) Robinson, Proc. Amer. Acad. 41: 272. 1905. 

 Ageratella microphylla palmeri A. Gray in S. Wats. Proc. Amer. Acad. 22: 419. 



1887. 

 Sinaloa and JaUsco; type from Rio Blanco, Jalisco. 



Suffrutescent, less branched, up to 60 cm. high; leaves alternate, the blades 

 narrowly oblanceolate to Unear, 10 to 22 mm. long, 1.5 to 3.5 mm. wide, subentire 

 or sparsely toothed ; heads 7 mm. high, numerous in a close or rather loose, spicate 

 or racemelike panicle. 

 57020—26 8 



