PECTIS POLYPTERIS 287 



with 2 awns ; receptacle flat, without chaff, involucre oblong, the bracts in 



1 row ; heads in cymes ; leaves opposite, narrow, entire, dotted with glands ; 



annual. 



Stems 4-12 in. high; leaves linear, .5-2 in. long; heads 



5-6 mm. wide P. angustifolia .' 



PERICOME Gray 1853 



(Gr. peri, around, kome f hair, from the hairy achenes) 

 Heads without rays, the disk-flowers yellow, perfect, achenes linear- 

 oblong with margins long-hairy, pappus a crown of fringed scales; in- 

 volucre bell-shaped, the bracts united by their edges ; heads in cymes ; leaves 

 opposite, long- tapering ; perennial. 

 Stems very bushy, 2-5 ft. high and wide; leaves 



hastate, 2-4 cm. long; heads 9-12 mm. wide P. cauddta 



PETASITES Gaertner 1791 COLTSFOOT 



(Gr. petasites, a broad-rimmed hat, from the broad leaves) 

 Heads tubular, or some with white pistillate rays, disk-flowers white 

 or purplish, perfect but sterile, achenes linear, pappus of hair-like bristles ; 

 receptacle flat, without chaff, involucre bell-shaped to cylindric, the bracts 

 equal in 1 row ; heads often dioecious, or somewhat so, in racemes or 

 corymbs; leaves basal, broad; perennial. 

 Flower-stalks .5-2 ft. high ; leaves triangular-ovate, 

 heart-shaped at base, white-woolly below, 4-10 in. 

 long P. sagittdta 



PLATYSCHKUHRIA Rydberg 1906 



(Gr. platys, flat, Schkuhria) 



Heads with yellow pistillate ray-flowers, disk-flowers yellow, perfect, 

 achenes linear-wedge-shaped, pappus of about 10 lance-linear abruptly 

 pointed scales; receptacle flat, without chaff, involucre bell-shaped or hemi- 

 spheric, the bracts nearly equal in 1-2 rows; heads solitary or somewhat 

 corymbose; leaves alternate, entire; perennial. 

 Stems 4-12 in. high; leaves oval to spatulate; heads 



10-12 mm. high; rays 6-9 P.integrifolia 



POLYPTERIS Nuttall 1818 

 (Gr. polys, many, pteris, wing) 



Heads with rose-purple pistillate ray-flowers in ours, the rays 3-cleft, 

 disk-flowers purplish, perfect, achenes linear to wedge-shaped, 4-angled, 

 pappus of 8-12 pointed scales ; receptacle flat, without chaff, involucre bell- 

 shaped, the bracts in 1-2 rows, usually colored; heads in corymbs; leaves 

 alternate or opposite, usually entire; annual. 



