Part 1, 1914] CARDUACEAE : HELENIEAE 45 



long, short- puberulcnt on the angles, striate and glabrous on the faces; squamellae unequal, 



obovate, those of the angles less than 1 mm. long, the intermediate still shorter. 



Type locality: Near Guerrero, Chihuahua. 

 Distribution: Chihuahua. 



3. Tetracarpum anthemoideum (DC.) Rydberg. 



Hopkirkia anlhemoidea DC. Prodr. 5: 660. 1836. 



Schkuhria Hopkirkia A. Gray, PI. Wright. 2: 94. 1853. 



Schkuhria anthemoides Coult.; Donn. Smith, Enum. PI. Guat. 4: 93. 1895. 



A branched annual; stem 3-5 dm. high, somewhat angled, sparingly puberulent and 



glandular-granuliferous; leaves pinnately 5-7-divided or the upper 3-divided or entire, with 



narrowly linear divisions, nearly glabrous and conspicuously punctate; peduncles 1-3 cm. long; 



involucre obpyramidal, 5-6 mm. high, 3-4 mm. broad; bracts 4 or 5, obovate, keeled, the 



scarious tips tinged with purple, subtended by 1 or 2 small bractlets; ray- flower solitary; 



ligule 1 mm. long; disk-flowers 2-4; corollas 3 mm. long; achenes 4 mm. long, elongate-ob- 



pyramidal, strongly villous on the 4 angles, strongly striate and somewhat pubescent on the 



faces; squamellae 3 mm. long, subequal, lanceolate, acute, usually awned and in age often 



3-cleft. 



Type locality: Real del Monte, Mexico. 



Distribution: Chihuahua to Arizona, Sonera, Jalisco, and Mexico. 



4. Tetracarpum guatemalense Rydberg, sp. nov. 



Schkuhria virgata Hemsl. Biol. Centr. Am. Bot. 2: 212, in part. 1881. Not Schkuhria virgata DC. 



1836. 

 Schkuhria anthemoides Coult. ; Donn. Smith, Enum. PI. Guat. 4: 93, in part. 1895. 



A slender annual; stem 2-4 dm. high, sparingly puberulent, with ascending branches; 



leaves alternate, pinnatifid with 3-5 linear-filiform divisions or the upper entire, glabrate, 



impressed-punctate, 2-3 cm. long; peduncles 3-5 cm. long; involucre about 5 mm. high and 



4 mm. broad; bracts obovate, somewhat carinate, glandular-punctate, purplish at the tips; 



ray-flower solitary or wanting; ligule oblong, fully 2 mm. long; disk-flowers 5-7; corollas 



2 mm. long; achenes 3 mm. long, obpyramidal, densely villous, hirsute on the margins, striate 



and muriculate on the faces; squamellae subequal, lanceolate, aristulate, about equaling the 



corolla. 



Type collected at Llano de San Juan de Dios, Guatemala, 1865, Bernoulli 135 (herb. Columbia 

 Univ.). 



Distribution: Guatemala and Salvador. 



5. Tetracarpum virgatum (Llave) Rydberg. 



Mieria virgata Llave; Llave & Lex. Nov. Veg. Descr. 2: 9. 1825. 

 Schkuhria virgata T>CVrodx.S:6S^. 1836. 



An erect annual; stem angled and strongly grooved, glandular-hispidulous, with ascend- 

 ing branches; leaves alternate, 2-3 cm. long, pinnatifid with filiform divisions, hispidulous and 

 impressed glandular-punctate; peduncles 1-3 cm. long; involucre obconic, 5 mm. high, 4 

 mm. broad; bracts 5, obovate, rounded at the apex, carinate, hispidulous and punctate, 

 yellowish-green, more or less purple-tinged on the margins, usually with 1 or 2 small oblong 

 bractlets below; ray-flowers solitary or wanting; ligule short, obovate, 1 mm. long; disk- 

 flowers 5-8; corolla 2 mm. long; achenes black, elongate-pyramidal, 4-angled, 3 mm. long, 

 hispid on the angles, minutely muriculate on the faces; squamellae 8, the four on the angles 

 lanceolate, acute, awned, 1-2 mm. long, purple-striate, the intermediate much smaller and 

 blunt. 



Type locality: Tacubaya, near Mexico. 

 Distribution: Durango to San Luis Potosi and Puebla. 



6. Tetracarpum Wislizeni (A. Gray) Rydberg. 



Schkuhria Wislizeni A. Gray, Mem. Am. Acad. II. 4: 96. 1849. 



A slender annual; stem 1-3 dm. high, minutely glandular-puberulent; leaves mostly 

 3-sected into filiform divisions, or the upper and lower entire, glandular-punctate, glabrous or 



