1254 CARDUACEAE 
Ligules short, often less than the diameter of the disk. 22. R. tenaz. 
b. Leaf-blades elongated-linear. GRAMINIFOLIAE. 
Plants pubescent: ligules crimson. 23. R. graminifolia. 
Plants glabrous: ligules yellow. 24. R. Mohri. 
Chaff of the receptacle aristate or subulate. TRILOBAE. 
Blades of the lower stem-leaves, or some of them, palmately 3-lobed or 3- 
parted, sometimes undivided. 
Disk 5-18 mm. broad : ray-flowers with ligules 1.5-2.5 em. long. 25. R. triloba. 
Disk 15-20 mm. broad : ray-flowers with ligules 2-3.5 em, long. 26. R. rupestris. 
raus of m lower stem-leaves, or some of them, pinnately 5-7-lobed or 5- 
-parted. 
Bracts of the involucres, or most of them, as long as the ligules of the 
ray-flowers: Alleghenian species. 27. R. Beadlei. 
Braets of the involucres, or most of them, not half as long as the ligules 
of the ray-flowers : Floridan species. 28. R. pinnatiloba. 
B. Stigmas with slender subulate tips: pappus wanting. 
Plants of annual or biennial duration. BICOLORES. 
Lower cauline leaves with blades 1-3 cm. broad. 29. R. bicolor. 
Lower cauline leaves broader. 30. R. flexuosa. 
Plants of perennial duration. HIRTAE. 
Well developed disks 1 em. in diameter or more: ligules of the ray-flowers 
large and showy. 
Leaf-blades never of an ovate type. 
Petioles'of the basal leaves not exceeding 1 dm. in length. 
Leaf-blades broader than linear. 
Main axis or stem not divergently branched. 
Upper stem-leaves elliptic-lanceolate, lanceolate or narrower. 31. R. hirta. 
Upper stem-leaves oblong, subcordate-clasping. 32. R. amplectens. 
Main axis or stem divergently branched, usually from near the : 
base. 33. R. divergens. 
Leaf-blades linear or linear-lanceolate, elongated. 34. R. sericea. 
Petioles of the basal leaves, or somefof them, conspicuously elongated. 35. R. longipes. 
Leaf-blades, or some of them, of an ovate type. eS 
Basal leaves 5-6 em. wide: involucral bracts often foliaceous. 36. R. Brittonii. 
Basal leaves narrower : involucral braets not foliaceous. 37. R. monticola. 
Well developed disks smaller: ligules of the ray-flowers short. 38. R. Floridana. 
1. Rudbeckia laciniàta L. Stems 6-20 dm. tall, usually branched above, glabrous or 
nearly so : leaf-blades various, rather thin, veiny ; those of the basal and lower stem-leaves 
pinnately 3-7-foliate or divided, those of the upper stem-leaves successively less deeply 
parted or lobed, or the upper ones merely toothed, incised or cleft, sometimes entire : heads 
several or numerous, showy : bracts of the involucre oblong or lanceolate, reflexed : ray- 
flowers 6-10, conspicuous ; ligules bright yellow, 2-4 cm. long, soon drooping : disk green- 
ish yellow, becoming oblong-conic: achenes quadrangular: pappus a short 4-toothed or 
nearly entire crown : chaff truncate, pubescent or canescent at the apex. 
In moist thickets, Quebec to Manitoba, Florida and westward. Summer and fall. 
2. Rudbeckia heterophylla Torr. & Gray. Stems 4-16 dm. tall, cinereous-pubescent, 
sparingly branched above: leaves various; blades of the basal and lower stem-leaves peti- 
oled, pinnately 3-5-parted or divided, the oval or oblong divisions toothed ; those of the 
upper stem-leaves ovate, simple or lobed, coarsely toothed, borne on short petioles : heads 
few or several, not very showy : bracts of the involucre oblong or oblong-lanceolate : ray- 
flowers few ; ligules yellow, 1-2.5 cm. long, eventually drooping : disks subglobose, 1-1.5 
cm. in diameter, greenish yellow : achenes prismatic, with a short coroniform pappus ac- 
centuated at the angles: chaff canescent at the apex. 
In swamps and damp places, Florida. Summer. 
3. Rudbeckia subtomentdsa Pursh. Stems 6-15 dm. tall, cinereous-pubescent, 
branched above: leaves with petioled blades, some or all of the lower ones 3-lobed or 3- 
parted, the terminal lobe elliptic to lanceolate, acuminate, serrate, the lateral lobes smaller 
and narrower, those of the upper stem-leaves mostly undivided : heads numerous, showy : 
bracts of the involucre linear or nearly so, acuminate : ray-flowers several ; ligules yellow, 
2-3 cm. long: disks hemispheric or ovoid-conic, brown-purple, anise-scented : achenes 
crowned with the crenately toothed pappus: chaff canescent at the apex. 
On prairies and in open grounds, Illinois to Missouri, Louisiana and Texas. Summer and fall. 
4. Rudbeckia Heliópsidis T. & G. Stems 3—7 dm. tall, glabrate or softly opc 
usually branched above: leaves various, the basal and lower ones borne on ee 
slender petioles, the upper with short petioles ; blades rather thin oblong-ovate to ova i 
lanceolate, 3-10 em. long, mostly acute or acuminate at the apex, serrate, cuneate or mie 
abrubtly contracted at the base: heads rather small, few or several: bracts of the s 
lucre shorter than the disk : ray-flowers few ; ligules light yellow : disks subglobose, à Wen 
1 em. in diameter : achenes quadrangular, the pappus nearly obsolete : chaff blunt, can 
cent at the apex. 
In woods and low grounds, Georgia and Alabama. Summer and fall. 
