96 SPRING FLORA 



4. AGOSBRIS. (Troximon). False Dandelion. 



Herbs with mostly basal leaves and yellow flowers (some- 

 times purplish on outside). Bracts of the bell-shaped involu- 

 cre imbricated. Achenes terete; usually distinctly 10-ribbed or 

 nerved; expanding- in fruit and forming a globose head; beaked 

 or beakless. Pappus-bristles fine and copious, capillary; white 

 or nearly so. 



Beak of achene 3-4 times its length 1. A. heterophylla 



Beak about as long 1 or somewhat longer than achene. 



Plants low; rays purplish-tinged on the out- 

 side 2. A. arachnoidea 



Plants tall; rays yellow throughout 3. A. elata 



Beak decidedly shorter than achene. 

 Leaves smooth at least in age. 



Leaves 2-ranked 4. A. parviflora 



Leaves not 2-ranked 5. A. glauca 



Leaves more or less pubescent even in age. ... 6. A. villosa 



1. A. heterophylla (Nutt.) Greene. (T. heterophyllum 

 Nutt.) A small annual. Leaves all basal or sometimes al- 

 ternate; villous-pubescent; linear to spatulate or elliptical; 

 with entire, dentate or sinuate-pinnatifid margins. Peduncles 

 slender, 4-12 inches high; often several. Heads quite small. 

 Bracts lanceolate; acuminate. Achenes ribbed on the inner 

 surface or merely nerved; their beaks filiform. Pappus silky; 

 white. On dry plains and mountain ridges. May-June. 4.300- 

 6,000 ft. 



2. A. arachnoidea Rydb. Perennial from a tap-root, more or 

 less woolly throughout. Leaves oblanceolate, more or less run- 

 cinate-lobed, long-acuminate; densely pubescent. Heads not 

 more than % inch broad; bracts in about 3 series, long-acumi- 

 nate. Flowers becoming purplish in age. Beak as long as 

 body of achene. Grassy plains. May-June. 



3. A. elata (Nutt.) Greene. (T. elatum (Nutt.) A, Nels.; T. 

 Nuttallii A. Gray). Annual, erect; pubescence sparse and hirsute 

 or none. Leaves oblanceolate or the lowest pinnatifid; densely 

 pubescent. Head when mature more than an inch in diameter; 

 rays large; involucre woolly. Pappus brownish. Achenes with 

 beak from y 2 to % inch long. Dry gravelly hillsides. May- 

 June. 



4. A. parvlflora (Nutt.) Dietr. (T. glaucum parviflorum A. 

 Gray). A glabrous perennial. Leaves narrowly linear; entire 

 and acuminate. Scape much longer than leaves. Head not 

 over an inch broad. Achenes a.bout 14 inch long. Rather dry 

 plains. May-July. 



5. A. glauca (Pursh) Greene. (T. glaucum Pursh). A glau- 

 cous and glabrous perennial. Leaves linear, lanceolate or 

 elliptical; entire, dentate or pinnatifid. Scape longer than the 

 leaves. Head 1-2 inches broad. Achenes about J /2 inch long. 

 Dry plains. May-July. 



5a. A. glauca pumila (Nutt.) (Agoseris Leontodon Rydb.) 

 Low and tufted; pubescent with ashy-gray hairs when young, 

 but becoming glabrate in age. Leaves lanceolate in outline, 

 more or less laciniate-pinnatifid. Outer rays usually purplish 

 on the outside. Beak striate throughout. Rather dry hills. 

 May. 



