COMFOSITAE (COMPOSITE FAMILY) 837 



• 



2. V. virginica L. Stem narrowly or interruptedly winged, downy-pubescent, 

 like the lower surface of the ovate-lanceolate feather-veined alternate leaves ; 

 heads in compound corymbs ; receptacle convex ; flowers white ; rays 3-4, oval'; 

 aohenes winged. — Dry soil, Pa. to Kan., and southw. Aug. 



* * Heads broader, solitary or few. 



3. V. helianthoides Michx. Perennial ; stem hairy, 1 m. or less high, widely 

 winged by the decurrence of the ovate to ovate-lanceolate sessile alternate leaves, 

 which are rough above and soft-hairy beneath ; involucre appressed ; rays 8-15, 

 pistillate or neutral, usually sterile; aohenes winged, tipped with 2 fragile awns. — 

 Prairies and copses, O. to la., soutliw. and southwestw. June, July. 



4. V. ENCELioiDES (Cav.) B. & H., var. exaukioiilXta Robinson & Green- 

 man. Annual, branching, 3-6 dm. high, cinereous ; leaves alternate, ovate or 

 cordate to deltoid-lanceolate, the petioles destitute of the wings or auricles 

 (characteristic of the typical more southern form) ; involucral bracts linear^ 

 equal, foliaceous, spreading ; rays numerous, fertile. — Kan. to Tex., and westw. •, 

 adventlve by roads, w. Mo.; also casual northeastw., e.g. in s. Me. (Parlin). 



54, C0RE6pSIS L. Tjckseed 



Heads many-flowered, radiate ; rays mostly 8, neutral, rarely wanting. In- 

 volucre double ; each series of about 8 bracts, the outer foliaceous and somewhat 

 spreading ; the inner broader and appressed, nearly membranaceous. Receptacle 

 flat, with membranaceous chaff deciduous with the fruit. Aohenes flat, obeom- 

 pressed (i.e. flattened parallel with the bracts of the Involucre), often winged, 

 not narrowed at the top, 2-toothed or 2-awned, or sometimes naked at the sum- 

 mit ; the awns not barbed downwardly. — Herbs, generally with opposite leaves 

 and yellow or party-colored (rarely purple) rays. Too near the last section of 

 Bidens, but generally well distinguished as a genus. (Name from xdpis, a bug, 

 and 6\j/ii, appearance ; from the form of the achene.) 



§ 1. Style-tips truncate or nearly so ; outer involucre small andshort; raysrose- 

 color or yellow, with brown base; pappus an obscure border or none. 



1. C. rbsea Nutt. Perennial; stem branching, leafy, smooth, 2-6 dm. high; 

 leaves linear, entire; heads small, somewhat corymbed, on short peduncles; 

 rays rose-color, 3-toothed ; achenes oblong, wingless. — Sandy grassy swamps 

 and shores, e. Mass. to N. J., and southw. July-Sept. 



2. C. tinctbria Nutt. Annual, glabrous, often 1 m. high; leaves 1-2-pin- 

 nately divided, the lobes lanceolate to linear ; achenes oblong, wingless ; rays 

 yellow, with more or less of crimson-brown. — Minn, to Tex., etc.; common in 

 cultivation ; often escaping to roadsides, etc., eastw. 



§2. Style-tips abruptly cuspidate, hispid; involucres nearly equal; achenes 

 roundish, winged, incurved, often papillose and with a callus inside at base 

 and apex; pappus 2 small teeth or none; rays mostly yellotv andpalmately 

 lobed; perennials, with long-pedunculate heads ; lower leaves petiolate. 



* Wings of achene broad, thin, spreading. 



3. C. lanceol&ta L. Smooth or hairy, 3-6 dm. high, tufted, branched only 

 at the base ; leaves all entire (the lower rarely with a pair of small lateral lobes) , 

 lanceolate, the lowest oblanceolate or spatulate; outer bracts ovate-lanceolate. 

 1-Rich or damp soil, Ont. and Mich, to Va., Mo., and southw.; also cultivated 

 on account of its showy heads, and sometimes escaping eastw. May-July. 



Var. yillbsa Michx. Hirsute below, the hirsute or villous leaves rather 

 broader. ( C. crassifolia Ait.) — 111. and Mo. to Fla. 



4. C. grandiflbra Hogg. Mostly glabrous ; lower leaves lanceolate and spatu- 

 late, entire, the upper 3-5-parted, with lanceolate to linear and sometimes 2-3- 

 parted lobes; heads as in the preceding or larger. — Damp soil, Mo. and e. 

 Kan. to Tex. and Ga. May-July. 



