1508 CONTRIBUTIONS FEOM THE NATIONAL HEEBARIUM 



Plants erect, not scandent, the branches straight; heads in large terminal 

 panicles. 

 Stem densely cinereous- or griseous-puberulous or hirtellous, sometimes 



tomentose 5. A. mucronata. 



Stem glabrous or essentially so, at least below, and often glaucous, rarely 

 sparsely arachnoid. 

 Leaves oval or ovate-oval, the larger 3 to 6 cm. wide. _ 6. A. sescenticeps. 

 Leaves narrowly lanceolate to elliptic or oblong, the larger 1 to 3.5 cm. 

 wide. 



Leaves narrowly lanceolate, glabrous 7. A. androgyna. 



Leaves chiefly elliptic, pubescent at least on the veins beneath. 



8. A. asperifolia. 



1. Archibaccharis oaxacana (Greenm.) Blake. 



Baccharis oaxacana Greenm. Proc. Amer. Acad. 40: 37. 1904. 



Heinihaccharis oaxacana Blake, Contr. U. S. Nat. Herb. 20: 546. 1924. 



Known only from the type locality, Sierra de San Felipe, Oaxaca. 



Suffrutescent at the procumbent base, 20 to 50 cm. high; leaves chiefly obovate 

 or oval, 4 to 8 cm. long, 1.5 to 3.5 cm. wide, including the rather abruptly con- 

 tracted, petiolifonii, marginate and amplexicaul basal portion, shallowly mucron- 

 ate-dentate; heads few in a terminal cymose panicle, the pistillate 1 cm. high, 

 the staminate about 8 mm. high. 



2. Archibaccharis pringlei (Greenm.) Blake. 



Baccharis pringlei Greenm. Proc. Amer. Acad. 41: 225. 1905. 



Hemibaccharis pringlei Blake, Contr. U. S. Nat. Herb. 20: 547. pi. Jf8. 1924. 



Known only from the type locality. Sierra de San Felipe, Oaxaca. 



Similar to B. oaxacana; leaves ovate, 4 to 12 cm. long, 2 to 5.5 cm. wide; 

 inflorescence a terminal many-headed panicle; staminate heads 5 mm. high; 

 pistillate heads unknown. 



3. Archibaccharis hirtella (DC.) Heering, Jahrb. Hamb. Wiss. Anst. 21: 



Beih. 3: 41. 1904. 



Baccharis scandens Less. Linnaea 5: 146. 1830. Not B. scandens Pers. 1807. 



Baccharis hirtella DC. Prodr. 5: 418. 1836. 



Baccharis schiedeana Benth. in Oerst. Nat. For. Kjobeiihavn Vid. Medd. 

 1852: 83. 1852. 



Baccharis thomasii Klatt, Abh. Naturf. Ges. Halle 15: 326. 1882. 



Hemibaccharis hirtella Blake, Contr. U. S. Nat. Herb. 20: 549. 1924. 



Tepic to Veracruz and Oaxaca; type from Mexico, without definite locality. 

 Guatemala. 



Suffrutescent, scandent, up to 5 meters high; stem slender, sordidly glandular- 

 puberulous or sometimes sordid-pilose; leaves short-petioled, the blades 2 to 6.5 

 cm. long, 1 to 2.5 cm. wide, acuminate, serrulate, pubescent or puberulous at 

 least beneath. 



4. Archibaccharis torquis Blake. 



Hemibaccharis torquis Blake, Contr. U. S. Nat. Herb. 20: 550. pi. 51. 1924. 



Veracruz and Oaxaca. Guatemala to Co.sta Rica; type from San Jose, Costa 

 Rica. 



. Stouter than A. hirtella; leaves oval or oval-ovate, the blades 3 to 8 cm. long, 

 1.8 to 5 cm. wide, acute; panicles and heads larger. 



5. Archibaccharis mucronata (H. B. K.) Blake. 

 Baccharis mucronata H. B. K. Nov. Gen. & Sp. 4: 60. 1820. 

 Pluchea floribunda Hemsl. Diag. PL Mex. 32. 1879. 



Hemibaccharis mucronata Blake, Contr. U. S. Nat. Herb. 20: 550. 1924. 

 Chihuahua to Oaxaca; type collected between Santa Rosa and Los loares, 



Guanajuato. 



