326 FLORA OF PHILADELPHIA. 



15. SEEICOCAEPUS Nees. White-topped Aster. 



Leaves entire, linear, spatulate or obovate, rigid. 1. S. linifolius. 



Leaves dentate, oblong or obovate, thin. 2. 8. asteroides. 



1. Sekicocarpus linifolius (L.) B. 8. P. M. p. 946. Dry, usually sandy 



soil. Summer and fall. 



Philadelphia— Germantown (Me.). Bucks— Bristol, Doylestown, A. S. 

 Martin (Ft.). Montgomery— pillow Grove (VP.). Delaware— Upper 

 Darby, below Llanereh (B. Sm.), Concord (W. Tr.). Chester— North of 

 Coatesville (St.). Lancaster— Pleasant Grove (Ca.). 



New Jersey — Frequent. , 



New Castle— Frequent. 



2. Sericocakpus asteroides (L.) B. S. P.. M. p. 946. Dry ground. Sum- 



mer and fall. 



16. ASTEE L. 



A. Basal and lower leaves, or some of them, cordate and slender-petioled. 



1. None of the stem-leaves cordate-clasping. 



*Eays white, violet or rose. 



fEays white or rarely rose, usually two-toothed; plants not 

 glandular. 

 Involucre ovoid, eampanulate or turbinate, its bracts mostly obtuse or 

 rounded; basal leaves few and small, or commonly none. 

 Leaves membranous or thin, smooth or nearly so. 



Heads 18-25 mm. broad; leaves of the branches small, obtuse or 



acute. 1. A. divaricatus. 



Heads 25 mm. broad or more; leaves of the branches large, long, 

 lanceolate, acuminate. 2. A. teneorosus. 



Leaves thick, firm, rough, at least when dry. 3. A. Claytoni. 



Involucre cylindric, its bracts tapering to an obtuse apex ; basal leaves large, 

 tufted. 4. A. Schreberi. 



ffEays violet, usually 3-toothed; plants glandular. 



5. A. macrophyllus. 

 **Eays blue or purple; plants not glandular. 



Heads 4-{> mm. high, numerous; bracts obtuse or obtusish. 



Leaves rough; petioles not wing-margined; bracts appressed. 



6. A. cordif alius. 

 Leaves smooth or nearly so; petioles, or some of them, wing-margined. 



7. A. Lowrieanus. 

 Heads 6-10 mm. high, numerous; bracts acute or acuminate. 



8. A. sagittifoli/us. ■ 



2. Stem-leaves, or some of them, cordate-clasping; plant rough when 



dry. 9. A. undulatus. 



B. No cordate and petioled leaves ; those of the stem, or some of them, with 



more or less auricled clasping base. 



1. Stem rough or hirsute-pubescent. 



"Leaves entire, oblong, linear or lanceolate. 



Heads 2.5-5 cm. broad ; leaves sessile, strongly cordate-clasping. 

 Stem rough, leaves oblong to lanceolate; involucre hemispheric. 

 Leaves thick, firm, very rough, oblong to oval. 10. A. patens. 



Leaves thin, roughish, oblong-lanceolate. 11. A. phlogifolius. 



Stem hirsute; leaves lanceolate; involucre hemispheric. 



12. A. Novae-Angliae. 

 Heads 1-2.5 cm. broad; leaves but slightly clasping. 



13. A. amethystinus. 

 **Leaves, at least the lower, serrate. 14. A. puniceus. 



2. Stem glabrous, or only sparingly pubescent above. 



*Leaves sharply serrate. 

 Leaves tapering to the base. 



Leaves lanceolate to oblong-lanceolate, sessile. 14. A. puniceus. 



