This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Perennial herbs, with alternate pinnately divided or parted leaves, and long-peduncled terminal heads of tubular and radiate flowers, the disk-flowers gray or yellow, becoming brown, the rays yellow, or with brown bases, drooping or spreading. Involucral bracts in 2 or 3 series. Disk globose, oblong or cylindric. Receptacle columnar to subulate, the concave chaff subtending or enveloping the disk-flowers, truncate, the tips inflexed, canescent. Ray-flowers neutral. Disk-flowers perfect, fertile, their corollas with scarcely any tube.
Achenes short, flattened, sharp-margined, or winged, at length deciduous with the chaff. Pappus with I or 2 teeth, or none. [Name unexplained.]
About 4 species, natives of North America. Type species: Rudbeckia columnaris Sims. Style-tips lanceolate-subulate; leaf-segments lanceolate; rays 1'-3' long.
Style-tips short, blunt; leaf-segments linear, rays 3"- 15" long.
Disk cylindric, at length 1' long or more; rays mostly as long, or longer.
2. R. columnaris.
Disk globose to short-oblong, about 1/2' high; rays mostly short.
3. R. Tagetes.
Rough and strigose-pubescent throughout; stem branched or simple, 3°-5° high. Leaves pinnately 3-7-divided, the basal ones sometimes 10' long, petioled, the segments lanceolate, dentate, cleft or entire, acute .or acuminate; upper leaves sessile or nearly so, the uppermost commonly small and entire; bracts of the involucre linear or linear-oblong, short, reflexed; rays 4-10, yellow, 1'-3' long, 3"-9" wide, drooping; style-tips lance-subulate; disk oblong, gray or becoming brown, rounded, at length twice as long as thick; chaff of the receptacle canescent at the summit; achenes compressed, acutely margined, the inner margin produced into a short tooth.
On dry prairies, Ontario and western New York to Florida, South Dakota, Nebraska, Kansas and Louisiana. Adventive eastward to Massachusetts. June-Sept.
Rudbeckia columnaris Sims, Bot. Mag. pl. 1601. 1813. Ratibida columnaris D. Don; Sweet, Brit. Fl. Gard. 2:
361. 1838. Lepachys columnaris T. & G. Fl. N. A. 2: 313. 1842. Lepachys columnaris var. pulcherrima T. & G. loc. cit.
Strigose-pubescent and scabrous; stem slender, usually branched, 1°-2 1/2° high. Leaves thick, pinnately divided into linear or linear-oblong, acute or obtuse, entire dentate or cleft segments, the cauline short-petioled or sessile, 2'-4' long, the basal ones sometimes oblong, obtuse and undivided, slender-petioled; bracts of the involucre short, linear-lanceolate or subulate, reflexed; rays 4-10, yellow, brown at the base, or brown all over, 4"-15" long, drooping; disk gray, elongated-conic or cylindric, blunt, at length 3 or 4 times as long as thick; chaff of the receptacle canescent at the apex; achenes scarious-margined or narrowly winged on the inner side; pappus of 1 or 2 subulate teeth usually with several short intermediate scales.
On dry prairies, Minnesota to Assiniboia, British Columbia, Montana, Nebraska, Texas, Mexico and Arizona. Also in Tennessee. Brush. May-Aug.
Rudbeckia Tagetes James in Long's Exp. 2: 68. 1823.
Lepachys Tagetes A. Gray, Pac. R. R. Rep. 4: 103. 1856.
Ratibida Tagetes Barnhart, Bull. Torr. Club 24: 100. 1897.
Rough-canescent; stem 1°-1 1/2° high, usually much branched, leafy. Leaves firm, pinnately divided into 3-7 narrowly linear, mostly entire segments; peduncles terminal, 1/2'-2' long; heads 1' broad, or less; bracts of the receptacle narrow, deflexed; rays few, mostly shorter than the globose to short-oval disk; style-tips obtuse; achenes scarious-margined; pappus of 1 or 2 subulate deciduous teeth, with no short intermediate teeth.
On dry plains and rocky hills, Kansas to Texas, Colorado, Chihuahua, New Mexico and Arizona. July-Sept.