Heliopsis. composite. 379 



1. Heliopsis l^evis, Pers, Ox-eye. 



Stem smooth ; leaves smgothish, varying from ovate to ovate-lanceolate or oblong-ovate, 

 coarsely serrate. — Pers. I. c. ; Pursh, ft. 2. p. 563 ; Ell. sk. 2. p. 407 ; Beck, hot. p. 204 ; 

 Darlingt. fl. Cest. p. 479 ; Hook. hot. mag. t. 3372 ; DC. prodr. 5. p. 550 ; Torr. 4- Gr. 

 fl. N. Am. 2. p. 302. Buphthalmum helianthoides, Linn. sp. 2. p. 904 ; Miclix.fl. 2. p. 180. 

 Silphium helianthoides, Linn. I. c. p. 920 (excl. syn. Gronov.). Rudbeckia oppositifolia, 

 Linn. I. c. Helianthus laevis, Linn. sp. ed. 2. (excl. syn. Gronov.). 



Stem 2-3 feet high, rather slender, terete, striate. Leaves 2-4 inches long and 1-2 

 inches broad, acute or acuminate, somewhat truncate at the base (rarely cordate), or abruptly 

 tapering into the petiole, usually nearly smooth, but sometimes the upper surface is rough 

 with very short scattered hairs which originate in minute tubercles : petioles 6-8 lines long, 

 margined. Heads on long peduncles, either solitary, or several in a loose fastigiate corymb. 

 Exterior scales of the involucre variable in length, usually as long as the disk but often 

 shorter, obtuse or rather acute, more or less foliaceous. Rays 10 - 15, three-fourths of an 

 inch long, elliptical-oblong, orange-yellow, 2 - 3-toothed at the apex. Receptacle small. 

 Chaff linear, rather obtuse. Achenia mostly 4-sided ; but those of the disk sometimes un- 

 equal, pentangular. 



Banks of streams and borders of swamps ; rather common. July - September. 



Div. 2. EnHELiANTHE^, Torr. & Gr. Rays ligvlate {neutral or imperfectly styliferous), sterile. 

 Achenia often compressed, but never obcompressed. Pappus coroniform, toothed, or of 

 1-4 awns, chaffy scales or squamellee, often wanting. 



22. RUDBECKIA. Linn.; Endl. gen. 2511 . rudbeckia. 



t Named in honor of Olads Rudbeck, professor of botany at Upsal in Sweden, who died in 1702.] 



Heads many-flowered ; rays neutral, in a single series ; disk-flowers tubular or dilated, perfect, 

 the teeth erect or spreading. Scales of the involucre leafy, somewhat in a double series, 

 spreading. Receptacle conical or elongated ; the chafi" concave or boat-form. Branches 

 of the style terminated by a short obtuse cone, or rarely with a narrow-headed appendage. 

 Achenium nearly quadrangular. Pappus none or minute and coroniform, rarely somewhat 

 conspicuous. — Mostly perennial herbs, with alternate leaves and rather large terminal heads. 

 Rays yellow, spreading or drooping. Disk-flowers mostly dark purple. 



1. Rudbeckia hirta, Linn. Large Hairy Rudbeckia. 



Plant very hairy or hispid ; stem nearly simple, naked above ; lower leaves spatulate-oval 

 or oblong, triplinerved, denticulate, narrowed into a (usually winged) petiole ; upper ones 

 ovate-lanceolate, sessile ; scales of the involucre linear ; rays spreading ; disk broadly conical ; 

 chaff of the receptacle linear, rather acute, hairy at the summit ; pappus obsolete. — Linn, 

 sp. 2. p. 907 ; Michx. fl. 2. p. 143 ; Pursh, fl. 2. p. 574 ; Ell. sk. 2. p. 457 ; Sweet,, Brit. 



48* 



