852 coMPOSiTAE (coMrosiTE family) 



leaves lanceolate or oblong, acute, cut-toothed, sessile, the upper auricled at 

 base or petioled. — Moist woods, and in recently burned clearings, whence the 

 popular name ; common, especially northw. July-Sept. 



78. CACAlIA L. Indian Plantain 



Heads 5-many-fiowered ; the flowers all tubular and perfect. Involucral 

 bracts in a single row, erect, connivent, with a few bractlets at the base. 

 Receptacle naked. Corolla deeply 5-cleft. Achenes oblong or slender-cylindric, 

 smooth; pappus of numerous soft capillary bristles. — Smooth and tall peren- 

 nial herbs, with alternate often petioled leaves, and rather large heads in flat 

 corymbs. Flowers white or whitish. (An ancient name, of uncertain meaning.) 



* Involucre 25-SO-flowered, vnth several bracts at its base; receptacle flat. 



1. C. suaveolens L. Stem grooved, 1-1.6 m. high ; leaves triangular- 

 lanceolate., halberd-shaped., pointed, serrate, those of the stem on winged 

 petioles. (Synosma Raf.) — River-banks, rich woods, etc., Ct. to la., Minn., 

 and southw. in the Allegheny region to Fla.; Newton, Mass. (Farlovj), where 

 probably an escape. Aug., Sept. 



* * Involucre ^'y-bracted and o-flovje7'ed, its basal bracts minute or none ; recepta- 

 cle bearing a more or less evident scale-like pointed appendage in the center. 



2. C. renif6rmis Muhl. (Great Indian P.) Not glaucous ; stem 1-3 m. 

 high, grooved and angled ; leaves green on both sides, dilated-fan-shaped., 

 or the lowest kidney-form., 3-6 dm. broad, repand-toothed and angled, palmately 

 veined, petioled ; the teeth pointed ; corymbs large. {Mesadenia Raf.) — Rich 

 damp woods, N.J. to Minn., and southw. along the mts. to N. C. and Tenn. 

 July, Aug. 



3. C. atriplicifolia L. (Pale Indian P.) Glaucous; stem terete, 1-2 m. 

 high; leaves palmately veined and angulate-lobed ; the lower triangular-kidney- 

 form or slightly heart-shaped ; the upper rhomboid or wedge-form, toothed. 

 {Mesadenia Raf.) — Rich woodlands and prairies, N. J. to Minn., Kan., and 

 sOUthw. in the Alleghenies to Ga, 



4. C. tuberbsa Nutt. Stem angled and grooved, 6-20 dm. high, from a 

 thick tuberous root; leaves green on both sides, thick, strongly b-1-nerved ; the 

 lower lance-ovate or oval, nearly entire, tapering into long petioles ; the upper 

 on short margined petioles, sometimes toothed at apex. {Mesadenia Britton.) — 

 Wet prairies, etc., O. and w. Ont. to Minn., Kan., and southw. 



79. SENECIO [Tourn,] L. Groundsel. Ragwort. Squaw-weed 



Revised by J. M. Greenman 



Heads many-flowered ; rays pistillate or none ; involucre cylindrical to bell- 

 shaped, simple or with a few bractlets at the base, the bracts erect-connivent. 

 Receptacle flat, naked. Pappus of numerous very soft and capillary bristles. — 

 Ours herbs, with alternate leaves and solitary or corymbed heads. Flowers 

 chiefly yellow. (Name from senex, an old man, alluding to the hoariness of 

 many species, or to the white hairs of the pappus.) 



a. Annuals (rarely becoming biennial) ; steins leafy to the inflores 

 cence ; heads medium-sized, 1 cm. or less high during anthesis 6 



b. Heads discoid 



h. Heads radiate ; rays inconspicuous. 



Pubescence viscid-glandular 



Pubescence not viscid-glandular 



. Heads radiate ; rays conspioious. 



Leaves irregularly laciniate-dentate to entire ; plant pubescent 

 I^eaves lyrate or pinnately divided ; i>lant glabrous 

 » Biennials or j)erennials c. 



c. Heads inediiim-sized. in anthesis about 1 cu). long d . 



d. Stems leafy to the inriorescencc ; leaves mostly 2-3-piunati3ect . 6. S. Jaeobaea^ 



1. S. vulgaris. 



2. S. visco8U8. 



3. S. syl/vaticua. 



4. S. pahiHtris. 



5. >S'. glabellus. 



