1254 CAEDUACEAE 



Ligules short, often less than the diameter of the disk. 22. R. lenax. 



b. Leaf-blades elongated-linear. GRAMINIFOLIAE. 



Plants pubescent : ligules crimson. 23. R. graminijolla. 



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 5-13 mm. broad : ray-flowers with ligules 1.5-2.5 cm. long. 25. R. triloba. 



Disk 15-20 mm. broad : ray -flowers with ligules 2-3.5 cm, long. 26. R. rupestris. 



Blades of the lower stem-leaves, or some of them, pinnately 5-7-lobed or 5- 



7-parted. 

 Bracts of the involucres, or most of them, as long as the ligules of the 



ray-flowers : Alleghenian species. 27. R. Beadlei. 



Bracts of the involucres, or most of them, not half as long as the ligules 



of the ray-flowers : Floridan species. 28. R. pinnatUoba. 



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. Tricolor. 



Lower cauline leaves broader. 30. R. flexuosa. 



Plants of perennial duration. HIRTAE. 



Well developed disks 1 cm. in diameter or more : ligules of the ray-flowers 



large and showy. 

 Leaf-blades never of an ovate type. 



Petiolesiof the basal leaves not exceeding 1 dm. in length. 



Leaf-blades broader than linear. 

 i 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. divergent. 



Leaf -blades linear or linear-lanceolate, elongated. 34. R. sericea. 



Petioles of the basal leaves, or somejof them, conspicuously elongated. 35. R. longipes. 

 Leaf-blades, or some of them, of an ovate type. 



Basal leaves 5-6 cm. wide : involucral bracts often foliaceous. 36. R. Brittonii. 



Basal leaves narrower : involucral bracts not foliaceous. 37. R. monticola. 



Well developed disks smaller : ligules of the ray-flowers short. 38. R. Floridana. 



1. Rudbeckia laciniata 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 4-1 6 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 subtpmentosa 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 Helidpsidis T. & G. Stems 3-7 dm. tall, glabrate or softly pubescent, 

 usually branched above : leaves various, the basal and lower ones borne on long 

 slender petioles, the upper with short petioles ; blades rather thin oblong-ovate to ovate- 

 lanceolate, 3-10 cm. long, mostly acute or acuminate at the apex, serrate, cuneate or more 

 abrubtly contracted at the base : heads rather small, few or several : bracts of the invo- 

 lucre shorter than the disk : ray-flowers few ; ligulea light yellow : disks subglobose, about 

 1 cm. in diameter : achenes quadrangular, the pappus nearly obsolete : chaff blunt, canes- 

 cent at the apex. 



In woods and low grounds, Georgia and Alabama. Summer and fall. 



