830 COMPOSITAE (COMPOSITE FAMILY) 



angular, truncate ; pappus none, or a mere border. Perennial herbs, resem- 

 bling Helianthus. Heads showy, peduncled, terminal. Leaves opposite, peti- 

 oled, triple-ribbed, serrate. Flowers yellow. (Name from T}\IOS, sun, and 5^ts, 

 appearance, from the likeness to the Sunflower.) 



1. H. helianthoides (L.) Sweet. Nearly smooth, 0.3-1.5 in. high ; leaves 

 ovate-lanceolate or oblong-ovate, rather narrowly pointed, occasionally ternate ; 

 bracts (as in the next) with a rigid strongly nerved base ; rays linear ; pappus 

 none or 0/2-4 obscure teeth. {H. laevis Pers.) Hanks and copses, Out. to 

 111., and south w. Aug. 



2. H. scabra Dunal. Roughish, especially the leaves, which are disposed to 

 be less narrowly pointed, the upper sometimes entire ; rays broadly oblong to 

 linear or oblanceolate ; pappus coroniform and chaffy or of 2 or 3 conspicuous 

 teeth. Me. to Man., s. to N. J. and Ark.; rare eastw. 



44. ECLIPTA L. 



Heads many-flowered ; ray short ; disk-flowers perfect, 4-toothed, all fertile. 

 Involucral bracts 10-12, in 2 rows, leaf-like, ovate-lanceolate. Receptacle flat, 

 with almost bristle-form chaff. Achenes short, 3-4-sided, or in the disk later- 

 ally flattened, roughened on the sides, hairy at summit ; pappus none or an 

 obscure denticulate crown. Annual rough herb, with slender stems and oppo- 

 site leaves. Heads solitary, small. Flowers white; anthers brown. (Name 

 from ticXelireiv, to be deficient, alluding to the absence of pappus.) 



1. E. Alba (L.) Hassk. Rough with fine appressed hairs ; steins procumbent 

 or ascending, 2-9 dm. high ; leaves lanceolate or oblong, acute at each end, 

 mostly sessile, slightly serrate ; rays equaling the disk. Wet river-banks and 

 waste places, Mass., westw. and south w.; in the Northeast an introduced plant. 

 (Trop.) 



45. TETRAGONOTHECA [Dill.] L. 



Heads many-flowered, radiate ; the rays 6-9, fertile. Involucre double, the 

 outer of 4 large and leafy ovate bracts, united below by their margins into a 

 4-angled or winged cup ; the inner of small chaffy bracts, as many as the ray- 

 flowers and partly clasping their achenes. Receptacle convex or conical, with 

 narrow and membranaceous chaff. Achenes very thick, obovoid, flat at the top ; 

 pappus none. Erect perennials, with opposite coarsely toothed sessile some- 

 times connate leaves, and large single heads of pale yellow flowers, on terminal 

 peduncles. (Name from rerpdyuvos, four-angled, and e-^K-rj, a case, from the 

 shape of the involucre.) 



1. T. helianthoides L. Villous and somewhat viscid, 3-7 dm. high, simple; 

 leaves ovate or rhombic-oblong, sessile by a narrow base ; involucral bracts and 

 rays 2-3 cm. long. Sandy soil, Va., and south w. June. 



46. RUDBECKIA L. CONE-FLOWER 



Heads many-flowered, radiate ; the rays neutral. Bracts of the involucre 

 leaf-like, in about 2 rows, spreading. Receptacle conical or columnar ; the short 

 chaff concave, not rigid. Achenes 4-angled (in our species), smooth, not mar- 

 gined, flat at the top, with no pappus, or a minute crown-like border. Chiefly 

 perennial herbs, with alternate leaves, and showy terminal heads ; the rays gen- 

 erally long, yellow, often darker at base. (Named in honor of the Professors 

 Rudbeck, father and son, predecessors of Linnaeus at Upsal.) 



* Ache nes annulate ch<& petofl/tinQ in <tc. 

 H- Disk hemispherical to ellipsoid-ovoid in fruit, il<irk jmrplr <>r }>rown. 



++ Lower leaves 3-lobed or parted. 

 1. R. triloba L. Hairy, biennial, much branched, 0.5-1.6 m. high ; branches 



