1598 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM 



In eastern Guatemala the leaves are placed on the flesh to kill carnivorous 

 insect larvae. 



la. Tridax procumbens ovatifolia Robins. & Greenm. Proc. Amer. Acad. 32: 

 7. 1896. 



Known only from the type locality, Yalalag, Oaxaca. 



Similar, more softly pubescent; leaves ovate, finel}' serrate, about 1.8 cm. 

 long, 1 cm. wide; phyllaries mostly broadly obovate. 

 2. Tridax candidissima A. Gray, Proc. Amer. Acad. 15: 39. 1879. 



San Luis Potosf; type from Angostura. 



Low, sufFruticulose, ascending; leaves 2.5 to 5 cm. long, about 1.5 mm. wide, 

 entire; heads solitary, discoid, j-ellow; achenes turbinate, densely silky; pappus 

 of 20 slender plumose awns, three times as long as the achene. 



85. HEMIZONIA DC. Prodr. 5: 692. 1836. 



Herbs, rarely fruticose; leaves (in ours) opposite below, alternate above, entire 

 or pinnatisect; heads (in ours) solitary or cymose-panicled, yellow, radiate; 

 involucre 1-seriate, the phyllaries herbaceous above, scarious-margined and 

 ampliate below and enfolding the gibbous subquadrangular rugose epappose ray 

 achenes; receptacle bearing a single series of paleae between the rays and the 

 disk flowers; disk (in ours) infertile, the achenes with a pappus of 6 to 12 awns or 

 squamellae. 



Leaves densely siiky-strigose 1. H. palmeri. 



Leaves green. 



Heads mostly solitary at tips of branchlets, forming a thyrse; leaves filiform. 



2. H. frutescens. 

 Heads solitary at tips of branches, cymosely arranged; leaves linear or linear- 

 lanceolate 3. H. greeneana. 



1. Hemizonia palmeri Rose, Contr. U. S. Nat. Herb. 1: 24. 1890. 

 Known only from the type locality, Guadalupe Island, Baja California, 

 Low, much branched, the woody stem becoming 1 cm. thick; leaves and young 



branches densely silky-strigose; leaves opposite below, crowded, oblanceolate or 

 linear, 1 to 1.8 cm. long, 1.5 to 3 mm. wide, entire, acutish; heads about 1.2 cm. 

 wide, densely panicled at ends of branches; rays 8; pappus of the disk achenes 

 of 6 to 12 h near-lanceolate acuminate denticulate awns, longer than the achene. 



2. Henaizonia frutescens A. Gray, Proc. Amer. Acad. 11: 79. 1876. 

 Known only from the type locality, Guadalupe Island, Baja California. 

 Fruticose, erect, about 60 cm. high, hirsute-pilose and glandular-viscid; 



flowering branches fastigiate, very leafy; leaves filiform, about 2.5 cm. long, 1 

 mm. wide, entire or with a pair of short lateral lobes; heads about 6 mm. high; 

 rays 8 or 9; pappus of the disk achenes of 5 linear or subulate fimbriate-dentic- 

 ulate paleae. 



3. Hemizonia greeneana Rose, Contr. U. S. Nat. Herb. 1: 24. 1890. 

 Known only from the type locality, Guadalupe Island, Baja California. 

 Suffruticose, 0.6 to 1 meter high, tufted, more or less pubescent and viscid; 



leaves of the sterile branches linear-lanceolate, 1.2 to 2 cm. long, pinnatisect 

 with 6 to 8 lobes, or sometimes entire, those of the flowering branches linear, 

 entire; rays 8; pappus of the disk achenes of 6 to 10 unequal paleaceous awns. 



86. JAUMEA Pers. Syn. PI. 2: 397. 1807. 

 Reference: Rydberg, N. Amer. Fl. 34: 3. 1914. 

 1. Jaumea peduncularis (Hook. & Arn.) Oliver & Hiern.; Oliver, Fl. Trop. 

 Afr. 3: 395. 1877. 

 Chaetymenia peduncularis Hook. & Arn. Bot. Beechey Voy. 298. pi. 62. 1837. 



