GENUS 60. THISTLE FAMILY. 469 
60. SPILANTHES Jacq. Stirp. Am. 214. pl. 126. 1763. 
Annual or perennial branching herbs, with opposite, usually toothed leaves and rather 
small, long-peduncled discoid and radiate heads, terminal, or in the upper axils, or rays 
wanting in some species. Involucre campanulate, its bracts in about 2 series, herbaceous, 
loosely appressed. Receptacle convex or elongated, chaffy, its chaff embracing the disk- 
achenes and at length falling away with them. Ray-flowers yellow, or white, pistillate, some- 
times wanting. Disk-flowers yellow, perfect, their corollas tubular with an expanded 4-5-cleft 
limb. Anthers truncate at the base. Style-branches of the disk-flowers long, sometimes 
penicillate at the summit. Ray-achenes 3-sided, or compressed, those of the disk-flowers 
compressed, margined. Pappus of 1-3 awns, or more. [Greek, spot- or stain-flower, not 
significant. ] 
About 30 species, natives of warm and tropical regions. Type species: Spilanthes urens Jacq. 
1. Spilanthes répens (Walt.) Michx. 
Spilanthes. Fig. 4441. 
Anthemis repens Walt. Fl. Car. 211. 1788. 
Spilanthes repens Michx. Fl. Bor. Am. 2: 131. 1803. 
S. americana repens A. H. Moore, Proc. Am. Acad. 
42: 547. 1907. P 
Perennial, usually rooting at the lower nodes; 
stem slender, simple or branched, spreading or 
ascending, 8’-2° long, pubescent, or nearly gla- 
brous. Leaves ovate to lanceolate, petioled, acute 
or acuminate at the apex, or the lower obtuse, 
coarsely toothed, or nearly entire, 1’-3’ long; 
heads long-peduncled, solitary at the end of the 
stem and branches, 6-10” broad; bracts of the 
involucre oblong to oblong-lanceolate, obtuse or 
acute; rays 812, yellow; receptacle narrowly 
conic; achenes oblong, most of them roughened 
when mature and hispidulous; pappus of I or 2 
very short awns, or none. 
In moist or wet soil, Missouri to Texas, east to 
South Carolina and Florida. June-Sept. 
61. RUDBECKIA L. Sp. Pl. 906. 1753. 
Perennial or biennial (rarely annual), mostly rigid, usually rough or hispid herbs, with 
alternate undivided lobed or pinnatifid leaves, and large long-peduncled heads of tubular 
(mostly purple) and radiate (yellow) flowers. Involucre hemispheric, itS bracts imbricated 
in 2-4 series. Receptacle conic or convex, with chaffy concave scales subtending or envelop- 
ing the disk-flowers. Ray-flowers neutral, the rays entire or toothed. Disk-flowers perfect, 
fertile, their corollas 5-lobed. Anthers entire or minutely 2-mucronate at the base. Style- 
branches tipped with hirsute appendages. Achenes 4-angled, obtuse or truncate at the apex. 
Pappus coroniform, sometimes of 2-4 short teeth, or none. [In honor of Claus Rudbeck, 
1630-1702, Swedish anatomist and botanist.] 
About 30 species, natives of North America and Mexico. In addition to the following, some 20 
others occur in the southern and western United States. Type species: Rudbeckia hirta L. 
Disk globose or ovoid and purple or dark brown in fruit; lower leaves entire or lobed. 
Lower leaves deeply 3-lobed or 3-divided. 
Plant more or less hirsute; leaves thin; chaff awned. 1. R. triloba. 
Plant scabrous; leaves thick; chaff blunt, pubescent at apex. 2. R. subtomentosa. 
Leaves neither 3-lobed nor 3-divided. 
Plants hispid; style-branches subulate. 
Stem leaves lanceolate to oblong; involucre shorter than the rays. 3. R. hir'a. 
Stem leaves oval to obovate; involucral bracts foliaceous, nearly as long as the rays. 
4. R. Brittonit. 
Plants pubescent or glabrate; style-branches obtuse. 
haff merely ciliate. 
Leaves denticulate or entire; rays 9”-12” long. 
Basal leaves narrowed at base. 5. R 
Basal leaves cordate at base. 6. R.umbrosa. 
Leaves dentate or laciniate; rays about 18” long. ‘ 7. R. speciosa. 
Chaff canescent. ’ 8. R. grandiflora. 
Disk elongated or cylindric in fruit, yellowish or gray. 
Leaves very thick, shallowly toothed. : 9. R. maxima. 
Leaves thin, pinnately divided or pinnatifid. 10. R. laciniata. 
