1. A. squarrsa, Nutt. Stem somewhat hairy, usually winged above (4--8 high); leaves alternate or the lower opposite, oblong or ovate-lanceolate, pointed at both ends; rays 2--8, irregular.--Rich soil, Penn. and W. New York to Iowa, and southward. Sept.

55. COREoPSIS, L. TICKSEED.

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

Involucre double; each of about 8 scales, the outer rather foliaceous and somewhat spreading; the inner broader and appressed, nearly membranaceous. Receptacle flat, with membranaceous chaff deciduous with the fruit. Achenes flat, obcompressed (i.e., parallel with the scales of the involucre), often winged, not narrowed at the top, 2-toothed or 2-awned, or sometimes naked at the summit, the awns not barbed downwardly.--Herbs, generally with opposite leaves, and yellow or party-colored, rarely purple, rays. (Name from ?????, _a bug_, and ????, _resemblance_; from the form of the achene.)

-- 1. _Style-tips truncate or nearly so; outer involucre small and short; rays rose-color or yellow with brown base; pappus an obscure border or none._

1. C. rsea, Nutt. Perennial; stem branching, leafy, smooth (6--20'

high); leaves linear, entire; heads small, somewhat corymbed, on short peduncles; rays rose-color, 3-toothed; achenes oblong, wingless.--Sandy gra.s.sy swamps, Plymouth, Ma.s.s., to N. J., and southward; rare. Aug.

2. C. cardamineflia, Torr. & Gray. Annual, 6'--2 high; leaves 1--2-pinnately divided, the lobes oval to lanceolate or above linear; rays yellow with brown-purple base; achenes short, smooth or papillose, winged.--Kan. to La. and Tex.

3. C. tinctria, Nutt. Annual, glabrous, 2--3 high; leaves 1--2-pinnately 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.

-- 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; ray mostly yellow and palmately lobed; perennials, with long-pedunculate heads; lower leaves petiolate._

4. C. lanceolata, L. Smooth or hairy (1--2 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 scales ovate-lanceolate.--Rich or damp soil, Mich. and Ill. to Va., and southward. July. Also cultivated in gardens. Heads showy; rays 1'

long.--Var. ANGUSTIFLIA, Torr. & Gray, is a low form with crowded narrow leaves and elongated peduncles.--Var. VILLSA, Michx., is hirsute below, the leaves rather broad.

5. C. grandiflra, Nutt. Mostly glabrous; lower leaves lanceolate and spatulate, entire, the _upper 3--5-parted with lanceolate to linear and sometimes 2--3-parted lobes_; heads as in the last or larger.--S. Mo. to Tex. and Ga.

6. C. p.u.b.escens, Ell. More leafy, 1--4 high, p.u.b.escent or nearly glabrous; leaves thickish, oblong or the lower oval-obovate and the upper oblong-lanceolate, entire or with 2--4 small lateral lobes; heads usually smaller.--Va. to S. Ill., Mo., and southward.

7. C. auriculata, Linn. p.u.b.escent or glabrous; stems 1--4 high, branching, sometimes with runners; leaves mostly petioled, the upper oblong or oval-lanceolate, entire; the lower oval or roundish, some of them variously 3--5-lobed or divided; outer scales oblong-linear or lanceolate; achenes narrowly winged and strongly involute.--Rich woods and banks, Va. to Ill., and southward. June--Sept.

-- 3. _Style-tips cuspidate; achenes oblong, nearly straight, without callus, the wing narrow or none; rays yellow, mostly entire or slightly toothed._

[*] _Outer scales narrow, about the length of the inner, all more or less united at base; rays mostly entire, acute; pappus 2-toothed or none; leaves opposite, sessile, mostly 3-divided, appearing as if whorled; perennial, 1--3 high._

[+] _Leaves 3-cleft, but not to the base._

8. C. palmata, Nutt. Nearly smooth, simple; leaves broadly wedge-shaped, rigid; the lobes broadly linear, entire, or the middle one 3-lobed.--Prairies, Mich. to Minn., and southwestward. July.

[+][+] _Leaves divided to the base, uppermost and lowest sometimes simple._

9. C. seniflia, Michx. Plant minutely soft-p.u.b.escent; leaves each divided into 3 sessile _ovate-lanceolate entire leaflets_, therefore appearing like 6 in a whorl.--Sandy woods, Va. and southward. July.

Var. stellata, Torr. & Gray. Glabrous, and the leaves narrower.--Va., Ky., and southward.

10. C. delphiniflia, Lam. Glabrous or nearly so; leaves divided into 3 sessile _leaflets_ which are 2--5-_parted, their divisions lance-linear_ (1--3" broad), rather rigid; disk brownish.--Pine woods, Va. and southward. July.

11. C. verticillata, L. Glabrous; leaves divided into 3 sessile _leaflets_ which are 1--2-_pinnately parted into narrowly linear or filiform divisions_.--Damp soil, from Ont. and Mich. to Md., Ark., and southward. Cultivated in old gardens, but not showy. July--Sept.

[*][*] _Outer scales narrow, shorter, all united at base; rays entire, obtuse; pappus none; leaves petiolate, pinnately 3--5-divided; perennial._

12. C. tripteris, L. (TALL COREOPSIS.) Smooth; stem simple (4--9 high), corymbed at the top; leaflets lanceolate, acute, entire.--Penn. to Wisc., Iowa, and southward. Aug.--Sept.--Heads exhaling the odor of anise when bruised; disk turning brownish.

[*][*][*] _Scales mostly distinct, the outer leafy, reflexed or spreading; achenes flat, obovate or cuneate-oblong, 1-nerved on each face, 2-toothed or 2-awned (rarely 4-awned); leaves petiolate, usually pinnately 3--7-divided, the lobes serrate; annuals (or biennial), branching. Approaching_ Bidens.

[+] _Rays conspicuous, golden yellow._

[++] _Achenes cuneate, obscurely ciliate or naked; outer scales about 8._

13. C. aurea, Ait. Nearly glabrous, 1--3 high; leaves variable, commonly 3--7-divided, or some or all undivided, the segments incisely serrate or lobed; _achenes broadly cuneate_, 1--2" long, with 2 _very short blunt spreading teeth_.--Wet ground, Va. to Fl.

14. C. trichosperma, Michx. (TICKSEED SUNFLOWER.) Smooth, branched; leaves short-petioled, nearly all 3--7-divided; leaflets lanceolate or linear, cut-toothed, or the upper leaves only 3--5-cleft and almost sessile; heads panicled-corymbose; _achenes narrowly wedge-oblong or the inner ones wedge-linear_, about 4" long, smooth or spa.r.s.ely hairy, marginless, _crowned with 2 erect triangular or awl-shaped stout teeth_.--Swamps, Ma.s.s. to Va. near the coast. Also Buffalo, N. Y., to Ill., where is a var. TENUiLOBA, Gray, with shorter achenes, approaching the last. Aug.--Oct.

[++][++] _Achenes obovate, very flat, with thin ciliate margins._

15. C. aristsa, Michx. Somewhat p.u.b.escent; leaves 1--2-pinnately 5--7-divided, petioled; leaflets lanceolate, cut-toothed or pinnatifid; heads panicled-corymbose; outer scales 8--10, not exceeding the inner, barely ciliate; _achenes_ with 2 (rarely 4) _long and slender diverging awns_ as long as the achene itself.--Swamps, Ohio to Mich., Minn., and southwestward. Aug.--Oct.--Var. MuTICA has two short divergent teeth or points in place of the awns.--W. Ill. and southwestward. Forms occur with the barbs of the awns spreading or retrorse, hybrids with _Bidens frondosa_ or other species.

16. C. involucrata, Nutt. Heads rather larger, the outer scales 12--20, mostly exceeding the inner, slender and hispid; achenes with 2 short acute teeth.--W. Ill. to Kan. and Tex.

[+][+] _Rays none, or rarely rudimentary; outer scales usually 3--5, loose, leafy, commonly surpa.s.sing the short-pedunculate heads; achenes narrowly cuneate; plants glabrous, 1--3 high; leaves petiolate._

17. C. bidentodes, Nutt. Paniculately branched; _leaves undivided, lanceolate_, coa.r.s.ely toothed, tapering at both ends; heads 6--10"

long; _achenes nearly subulate_, bearing a pair of _very slender_ upwardly roughened _awns surpa.s.sing the corolla_ (4" long), but shorter than the achene, often also 2 minute teeth alternate with the awns.--Sh.o.r.es of Delaware River, near Philad., and Delaware Bay, to Md.

Hybridizes with _Bidens frondosa_.

18. C. discoidea, Torr. & Gray. Diffusely branched, 1--2 high; _leaves ternately divided_, slender-petioled; leaflets ovate-lanceolate, pointed, coa.r.s.ely serrate; heads 2--3" long; _achenes linear-wedge-shaped_ (2--3" long), bearing a pair of _short and stout_ upwardly-barbed _awns of the length of the corolla_.--Wet banks and swamps, Conn. to Ohio, Ill., and southward. July.

56. BDENS, L. BUR-MARIGOLD.

Heads many-flowered; the rays when present 3--8, neutral. Involucre double, the outer commonly large and foliaceous. Receptacle flattish; the chaff deciduous with the fruit. Achenes flattened parallel with the scales of the involucre, or slender and 4-sided, crowned with 2 or more rigid and persistent awns which are downwardly barbed.--Annual or perennial herbs, with opposite various leaves, and mostly yellow flowers. (Latin, _bidens_, two-toothed.)

[*] _Achenes flat, not tapering at the summit; outer involucre foliaceous; annuals._

[+] _Heads erect, nearly rayless; leaves mostly petiolate._

1. B. frondsa, L. (COMMON BEGGAR-TICKS. STICK-TIGHT.) Smooth or rather hairy, tall (2--6 high), branching, _leaves 3--5-divided; leaflets mostly stalked_, lanceolate, pointed, coa.r.s.ely toothed; outer involucre much longer than the head, ciliate below; _achenes wedge-obovate, 2-awned, ciliate_ (the bristles ascending except near the summit).--Moist waste places; a coa.r.s.e troublesome weed, the achenes, as in the other species, adhering to clothing, etc., by their retrorsely barbed awns. Hybrids occur with _Coreopsis aristosa_ and other species.

July--Oct.

2. B. connata, Muhl. (SWAMP BEGGAR-TICKS.) Smooth (1--2 high); _leaves lanceolate_ or oblong-lanceolate, pointed, sharply serrate, tapering into margined slightly united petioles; _the lower often 3-divided, their lateral divisions united at the base and decurrent on the petiole_; outer scales longer than the head, few, mostly obtuse; _rays none; achenes narrowly wedge-form, 3- (2--4-) awned, the margins minutely retrorsely ciliate_.--E. New Eng. to Minn., and southward.--Var. COMSA, Gray, is stouter, the leaves commonly all simple, upper ones nearly sessile, the heads larger and with very leafy involucre. Ill., Ky., and westward. Aug.--Oct.--Var. PINNaTA, Watson; leaves nearly all pinnately divided, the 5--7 narrow divisions sparingly incised; achenes 4-awned. Hennepin Co., Minn. (_F. L. Conillard_).

[+][+] _Heads somewhat nodding, commonly radiate; leaves sessile, undivided._

3. B. cernua, L. (SMALLER BUR-MARIGOLD.) Nearly smooth (5'--3 high), _leaves lanceolate, unequally serrate, scarcely connate; heads_ nodding, _with or without_ (light yellow) _rays_; outer involucre longer than the head; achenes wedge-obovate, 4-awned, the margins downwardly barbed.--Wet places, N. Eng. to Va., Mo., Minn., and northward.

July--Sept.--Rays, if any, smaller than in n. 4, and the outer involucre more leaf-like. (Eu.)

4. B. chrysanthemodes, Michx. (LARGER BUR-MARIGOLD.) Smooth, erect, or reclining at the base (6'--2 high); _leaves lanceolate_, tapering at both ends, more or less connate, _regularly serrate_; outer involucre mostly shorter than the _showy golden-yellow (1' long) rays_; achenes wedge-shaped, with almost p.r.i.c.kly downwardly barbed margins; awns 2, 3, or 4.--Swamps; common. Aug.--Oct.

[*][*] _Achenes linear, 4-sided, the inner longer and tapering upward._

5. B. bipinnata, L. (SPANISH NEEDLES.) Smooth annual, branched; leaves 1--3-pinnately parted, petioled; leaflets ovate-lanceolate, mostly wedge-shaped at the base; heads small, on slender peduncles; outer involucre of linear scales equalling the short pale yellow rays, achenes 4-grooved and angled, nearly smooth, 3--4-awned.--Damp soil, R. I. to N. Y., Ill., and southward.

[*][*][*] _Achenes terete, truncate at both ends, with 3--6 very long awns smooth below._