174 Trans. Acad. Sci. of St. Louis. 



ANALYSIS OF SPECIES. 



Heads homogamous, middle-sized or small, 4-8 mm. high; involucre 

 turbinate; achenes much broadened upward, 3-6 mm. long. 



Stems zigzag, slender, much branched, the branches widely diverging, 

 whitish, glaucous; leaves very narrow, linear, 1-nerved, thickish; 

 heads smallest, flowers flesh -colored; peduncles short, slender, 

 densely glandular. 1. Othake callosum. 



Stems straight, slender, few -branched, branches ascending; leaves 

 broader, linear-lanceolate, 1-nerved; heads somewhat larger, more 

 numerous flowered, flowers bright rose-colored; peduncles very 

 slender, longer, scabrous and glandular. 2. Othake roseum. 



Stem stout, straight, little branched, branches ascending; leaves 

 broadest, ovate-lanceolate, thin, 3 -nerved; heads large, many- 

 flowered, flowers rose-purple; peduncles short, stout, somewhat 

 glandular. 3. Othake Texanum. 



Heads beterogamous, middle-sized or large, 1-2 cm. high; involucre 

 obconic; achenes slender, linear, scarcely broadened upward, 4-8 

 mm. long; bracts of the involucre hispid and glandular. 



Heads largest; involucral bracts 1 cm. or less long; leaves indistinctly 

 3-nerved, lower opposite; peduncles very stout, densely scabrous- 

 pubescent. 4. Othake Hookerianum. 



Heads middle-sized; involucral bracts 1-2 cm. long or longer; leaves all 

 alternate, distinctly 3-nerved; plants densely glandular all over; 

 peduncles stout. 5. Othake maximum. 



Heads smaller; involucral bracts shorter; leaves smoother, indistinctly 

 3-nerved; plants minutely scabrous or nearly smooth; peduncles 

 long, very slender, diverging, sparingly glandular. 



6. Othake Reverchoni. 



1. Othake callosum (Nutt.) Bush. 



Stevin callosa Nutt. Journ. Acad. Philad. 2 : 121 (1821) . 

 Florestina callosa (Nutt.) D.C. Prodr. 5:655 (1836). 

 Othake tenuifolmm Raf. New Fl. Am. 4 : 74 (1836). 

 Palafoxia callosa (Nutt.) T. & G. Fl. N. A. 2 : 369 (1842). 

 Poly pteris callosa (Nutt.) Gray, Proc. Am. Acad. 19:30 (1883). 



Stems slender, widely much branched, appressed strigose- 

 pubescent, glandular above, 2-6 dm. high. Leaf-blades very 

 narrow, linear, thickish, obtuse or acutish, rough on both 

 sides, the upper alternate, the lower opposite and short- 

 petioled, 1-nerved, the edges revolute, 2-5 cm. long, 1-3 mm. 

 wide, the upper gradually reduced. Involucre campanulate, 

 3-4 mm. high, its bracts linear, 3-4 mm. long, appressed, 

 canescent, eglandular or rarely glandular, in two series, both 



