186 COMPOSITE. (COMPOSITE FAMILY.) 



§ 1. Annuals: receptacle flat or nearly so: all but the lower leaves usually alter- 

 nate, jxtiohd, 3-ribbed: involucre spreading ; its bracts attenuate : disk brown- 

 ish or dark purple. 



1. H. annuus, L. Robust, when well developed tall, hispid, hispidulous, 

 or scabrous : stem often spotted or mottled : leaves ovate and the lower cordate, 

 serrate, the larger (Wo 12 indies long, the blade of the cauliue ones longer than 

 their petiole : bracts of the involucre from broadly ovate to oblong, aristiform- 

 acuminate, below hispid/ / ciliate: disk in the wild plant commonly an inch or 

 more in diameter. — Includes //. lenticularis, Dougl., and many other forms. 

 From the Saskatchewan to Texas and westward. The " Common Sunflower," 

 extensively cultivated everywhere and thus becoming very tall and with enor- 

 mous heads. Fruit used by the Indians for food and oil. 



2. H. petiolaris, Nutt. A foot to a yard high, more slender, loosely 

 branching, strigose-hispidulous, rarely hirsute: leaves oblong-lanceolate or ovate- 

 lanceolate, entire or sparingly denticulate, 1 to 3 inches long, cuneately attenuate 

 or the lower abruptly contracted into* a long and slender petiole : bracts of the 

 involucre lanceolate or oblong lanceolate, with acute and mucronate or some- 

 times more attenuate tips, seldom at all ciliate: disk \ inch or more in diame- 

 ter. — About the same range as the last. 



§ 2. Perennials : receptacle convex, or at length low-conical: lower leaves almost 



always opposite. 



* Involucre loose, becoming more or less squarrose ; its bracts almost equal, filiform- 



attenuate: disk usually dark purple or turning brownish : all but the lower leaves 

 long-linear or filiform. 



3. H. orgyalis, DC. Stem smooth and glabrous, often 10 feet high, 

 very leafy to the top : leaves mostly alternate, from long-linear, 8 to 16 inches 

 long, commonly 2 to 4 lines wide, or the lowest lanceolate, to almost filiform, 

 slightly papillose-scabrous, the lower narrowed into a petiole and sometimes 

 serrulate : bracts of the involucre filiform-attenuate, those of the receptacle 

 entire : akenes oblong-obovate with a rounded summit, 3 lines long. — Dry 

 plains, Nebraska to Texas, west to S. E. Colorado. 



* * Involucre closer, of more imbricated and unequal ovate or oblong but not folia- 



ceous bracts: I eaves from lanceolate to ovate: herbage not tomentose nor con- 

 spicuously cinereous. 



4. H. rigidus, Desf. A foot or two (rarely 6 to 8 feet) high, rigid, spar- 

 ingly branched : leaves very firm-coriaceous and thick, both sides hisp/dulous- 

 scabrous, shagreen-like, entire or serrate ; lower oblong and ovate-lanceolate, 

 attenuate at base into short winged petioles ; upper mostly lanceolate : heads 

 comparatively large, showy; disk f inch high, dark purple or brownish: invo- 

 lucre piuri serially imbricated ; its bracts mainly ovate, obtuse or acutish, rigid, 

 appressed, densely and minutely ciliate. — Plains and prairies from Michigan 

 to Texas and west to E. Colorado. 



5. H. pumilus, Nutt. Hispid and scabrous throughout : stems simple, a 

 foot or two high, bearing 5 to 7' pairs of leaves and a few rather short- peduncled 

 heads : leaves mostly ovate-lanceolate, acute, entire or nearly so, 1 J to 4 inches 

 long, rigid, abruptly contracted at base into a short margined petiole : invo- 

 lucre less than half-inch high, white hirsute or scabro-hispidulous ; its bracts 



