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 ij\ios, sun, and fr/us, 

 appearance, from the likeness to the Sunflower.) 



1. H. helianthoides (L.) Sweet. Nearly smooth, 0.3-1.5 m. 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.) Banks and copses, Out. to 

 111., and south w. Aug. 



2. H. sc&bra Dunal. Boughish, 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 tK\ei-rreiv, to be deficient, alluding to the absence of pappus.) 



1. E. alba (L.) Hassk. Rough with fine appressed hairs ; stems 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 southw. ; 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 Terpdyuvos, four-angled, and 6-^Kr], 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 southw. 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.) 



* Achenes angulate ; chaff persisting in age. 

 H- Disk hemispherical to ellipsoid-ovoid in fruit, dark purple or brown. 



t-f Lower leaves 3-lobed or parted. 

 1. R. trfloba L, Hairy, biennial, much branched, 0.5-1.5 m. high ; branches 



