APRIL, 1904. PLANTS YUCATAJSME MILLSPAUGH & CHASE. 121 



on stout, rough peduncles, subcernuous. Heads 2 cm. high, 

 cm. or more broad; ray flowers 20-30, disk flowers numerous, 

 lucral bracts subequal in 3-4 

 series, ovate, long-acuminate, 

 hispid-ciliate, loose and spread- 

 ing. Rays yellow, tube very 

 short, ligule elliptic, 3-6 cm. 

 long, entire, spreading; disk 

 corollas dilated and hirsute be- 

 low, limb brownish purple, 5 

 lobed. Receptacle convex, de- 

 pressed in the center; scales 

 dark purple, keeled, acuminate, 

 3 dentate. Achenes slate color, 

 4-5 x 8-10 mm., obovate-oblong; 

 in section rhombic; appressed 

 villous, more dense at the sum- 

 mit; pappus of 2 purple, denticu- 

 late, chaffy scales, caducous. 



Hab. Campo, suburbs of Uman, escaped from cultivation, 

 1887, Millspaugh 32. 



Called GIRASOL, FLOR DE SOL, HELIANTO, and MIRASOL, 

 Yucatecans. 



10-15 

 Invo- 



April, 

 by the 



AMELLUS P. Br. Jam. PL, 317 excl. syn. 0/z Linn. 



Heads (in our species) homogamous, discoid, flowers perfect, 

 fertile, tubular. Involucre depressed hemispheric of subequal herba- 

 ceous bracts, imbricated in 2-3 series. Receptacle convex or conoid, 

 chaffy; scales concave, enfolding or subtending the disk flowers, per- 

 sistent on the receptacle. Achene laterally compressed, 4 angled, 

 hard; pappus of 2-8 distinct, setiform caducous bristles. Herbs with 



inconspicuous heads of white flow- 

 ers; anthers black. 



Amellus niveus (L.) Ktz. Rev. 



Gen. PI., i :3o6. 

 Bidens nivea L. 



A perennial herb with 4-angled, 

 scabrous stem and branches, and 

 opposite, petioled, ovate-lanceolate 

 usually hastately lobed, serrate, 

 hispid leaves. Inflorescence of 

 solitary, long-peduncled, terminal 

 and axillary heads; peduncles slen- 

 der, compressed, hispid. Heads 

 7-10 mm. high, 12-15 mm. broad, 

 many flowered. Involucral bracts 

 appressed, ovate, the outer sub- 

 acute, inner abruptly acuminate, clothed with stiff white hairs arising 

 from a swollen base. Corolla white, limb cylindrical, elongated 5 



