Part 39

C. LEUCANTHEMUM, L. (OX-EYE or WHITE DAISY. WHITE-WEED.) Stem erect, nearly simple, naked above and bearing a single large head; root-leaves spatulate, petioled, the others partly clasping, all cut or pinnatifid-toothed; scales of the involucre with rusty-brown margins. (Leucanthemum vulgare, _Lam._)--Fields and meadows; abundant eastward. June, July. A pernicious weed, with large and showy heads. It occurs with abortive, deformed, or tubular and laciniate rays. (Nat. from Eu.)

C. PARTHENIUM, Pers. (FEVERFEW.) Tall, branched, leafy; leaves twice-pinnately divided, the _divisions ovate, cut; heads corymbed_, rather small. (Leucanthemum Parthenium, _Godron_.)--Escaped from gardens in some places. (Adv. from Eu.)

70. TANACETUM, L. TANSY.

Heads many-flowered, nearly discoid; flowers all fertile, the marginal chiefly pistillate and 3--5-toothed. Involucre imbricated, dry. Receptacle convex, naked. Achenes angled or ribbed, with a large flat top; pappus a short crown.--Bitter and acrid strong scented herbs (ours perennial), with 1--3-pinnately dissected leaves, and corymbed heads. Flowers yellow; in summer. (Name of uncertain derivation.)

T. VULGARE, L. (COMMON TANSY.) Stem (2--4 deg. high) smooth; leaflets and the wings of the petiole cut-toothed; corymb dense; pistillate flowers terete, with oblique 3-toothed limb; pappus 5-lobed.--Var. CRISPUM has the leaves more cut and crisped.--Escaped from gardens to roadsides; Atlantic States. (Nat. from Eu.)

1. T. Huronense, Nutt. Hairy or woolly when young, stout (1--3 deg. high); lobes of the leaves oblong; heads large (1/2--{2/3}' wide) and usually few; pistillate flowers flattened, 3--5-cleft; pappus toothed.--St. John's River, Maine (_G. L. Goodale_), shores of the upper Great Lakes, and westward.

71. ARTEMISIA, L. WORMWOOD.

Heads discoid, few--many-flowered; flowers all tubular, the marginal ones pistillate, or sometimes all similar and perfect. Involucre imbricated, dry and scarious. Receptacle small and flattish, naked. Achenes obovoid, with a small summit and no pappus.--Herbs or shrubby plants, bitter and aromatic, with small commonly nodding heads in panicled spikes or racemes; flowering in summer. Corolla yellow or purplish. (Ancient name of the Mugwort, in memory of _Artemisia_, wife of Mausolus.)

Sec. 1. _Receptacle smooth; marginal flowers pistillate and fertile; disk-flowers perfect but sterile, the style mostly entire; root perennial, except in n. 1._

[*] _Leaves dissected._

1. A. caudata, Michx. Smooth (2--5 deg. high); upper leaves pinnately, the lower 2--3-pinnately divided; _the divisions thread-form_, diverging; _heads small, the racemes in a wand-like elongated panicle_; root biennial.--Sandy soil, coast of N. H. to Va.; also Mich. to Minn., and southward.

2. A. Canadensis, Michx. Smooth, or hoary with silky down (1--2 deg. high); lower leaves twice-pinnately divided, the upper 3--7-divided, _the divisions linear, rather rigid; heads rather large, in panicled racemes_.--Northern N. Eng. to the Great Lakes, Minn., and northward. (Eu.)

[*][*] _Leaves entire or some 3-cleft._

3. A. dracunculoides, Pursh. Tall (2--5 deg.), somewhat woody at base, slightly hoary or glabrous; leaves linear and entire or the lower 3-cleft; heads small and numerous, panicled.--Sandy banks of streams, Minn. to Ill., Mo., and westward.

4. A. glauca, Pall. Strict, 1--2 deg. high, somewhat woody at base, minutely silky-pubescent or glabrate; leaves linear- to oblong-lanceolate; heads as in the last.--Sask. to Minn. (Sib.)

5. A. filifolia, Torr. Suffruticose, finely canescent, 1--3 deg. high; leaves all filiform, the lower commonly 3-parted; heads very small and numerous, crowded in a long leafy panicle.--Central Kan. to Neb., and southwestward.

Sec. 2. _Receptacle smooth; flowers all fertile, a few pistillate, the others perfect._

Two cultivated shrubby species, from Europe, with filiformly divided leaves, have occasionally escaped from gardens and become spontaneous, viz., A. ABROTINUM, L. (the SOUTHERNWOOD), of strict habit, with leaves 1--2-pinnatifid and pubescent heads, and A. PROCERA, L., with more spreading branches, all the leaves finely 2-pinnatifid, and heads glabrous.

[*] _Tall (1--5 deg.) and branching perennials, whitened with fine and close-pressed wool; heads small, in leafy panicles._

6. A. serrata, Nutt. Very leafy, 6--9 deg. high; leaves lanceolate or the upper linear, serrate, white-tomentose beneath, green above; heads greenish, oblong, 2'' long or less.--Ill. to Dak.

7. A. longifolia, Nutt. Stem 2--5 deg. high; leaves linear or linear-lanceolate, entire, usually glabrate above; heads oblong, canescent, 2--3'' long--Minn. to Neb., and westward.

8. A. Ludoviciana, Nutt. (WESTERN MUGWORT.) _Whitened woolly_ throughout; _leaves lanceolate_, the upper _mostly entire_, the lower usually cut-lobed, toothed or pinnatifid, the upper surface sometimes glabrate and green; heads campanulate, mostly sessile in narrow panicles.--Dry banks, Sask. to Mich., Ill., Tex., and westward. Very variable.

A. VULGARIS, L. (COMMON MUGWORT.) _Leaves mostly glabrous and green above_, beneath and the branches white-woolly, all pinnatifid, with the divisions often cut-lobed, linear-lanceolate; heads small in open panicles.--Waste places, near dwellings. (Adv. from Eu.)

[*][*] _Densely white-tomentose perennial; heads large, racemose-glomerate._

9. A. Stelleriana, Bess. Stout, 1--2 deg. high, from a creeping base; leaves obovate or spatulate, pinnatifid, the lobes obtuse.--Sandy sea-beaches, E. Mass.; locally nat. from N. E. Asia?

[*][*][*] _Less branched (1--3 deg.), biennial or annual, glabrous._

10. A. biennis, Willd. Strict, 1--3 deg. high; lower leaves twice-pinnately parted, the upper pinnatifid; lobes linear, acute, in the lower leaves cut-toothed; heads in short axillary spikes or clusters, crowded in a narrow and glomerate leafy panicle.--Gravelly banks, Ohio to Tenn., Mo., and northwestward; rapidly extending eastward by railroad to Buffalo, Philadelphia, etc.

A. ANNUA, L. Tall, much branched; leaves 2-pinnately divided, the oblong segments deeply pinnatifid; heads small, in a loose ample panicle.--Ind. to Kan. (Nat. from Old World.)

Sec. 3. _Receptacle hairy; flowers all fertile, the marginal ones pistillate._

A. ABSINTHIUM, L. (WORMWOOD.) Rather shrubby (2--3 deg. high), silky-hoary; leaves 2--3-pinnately parted, lobes lanceolate; heads hemispherical, panicled.--Roadsides, escaped from gardens. (Adv. from Eu.)

11. A. frigida, Willd. Low (6--20' high), in tufts, slightly woody at the base, white-silky; leaves pinnately parted and 3--5-cleft, the divisions narrow-linear; heads globose, racemose.--Dry hills and rocks, Sask. to Minn., W. Tex., and westward.

72. TUSSILAGO, Tourn. COLTSFOOT.

Head many-flowered; ray-flowers in several rows, narrowly ligulate, pistillate, fertile; disk-flowers with undivided style, sterile. Involucre nearly simple. Receptacle flat. Achenes cylindrical-oblong; pappus copious, soft and capillary.--A low perennial, with horizontal creeping rootstocks, sending up simple scaly scapes in early spring, bearing a single head, and producing rounded-heart-shaped angled or toothed leaves later in the season, woolly when young. Flowers yellow. (Name from _tussis_, a cough, for which the plant is a reputed remedy.)

T. FARFARA, L.--Wet places, and along brooks, N. Eng., N. Y., and Penn.; thoroughly wild. (Nat. from Eu.)

73. PETASITES, Tourn. SWEET COLTSFOOT.

Heads many-flowered, somewhat dioecious; in the substerile plant with a single row of ligulate pistillate ray-flowers, and many tubular sterile ones in the disk; in the fertile plant wholly or chiefly of pistillate flowers, tubular or distinctly ligulate. Otherwise as Tussilago.--Perennial woolly herbs, with the leaves all from the rootstock, white-woolly beneath, the scape with sheathing scaly bracts, bearing heads of purplish or whitish fragrant flowers, in a corymb. (The Greek name for the coltsfoot, from [Greek: pe/tasos], a broad-brimmed hat, on account of its large leaves.)

[*] _Pistillate flowers ligulate; flowers whitish._

1. P. palmata, Gray. Leaves rounded, somewhat kidney-form, palmately and deeply 5--7-lobed, the lobes toothed and cut. (Nardosmia palmata, _Hook._)--Swamps, Maine and Mass. to Mich., Minn., and northwestward; rare. April, May.--Full-grown leaves 6--10' broad.

2. P. sagittata, Gray. Leaves deltoid-oblong to reniform-hastate, acute or obtuse, repand-dentate.--N. Minn. and westward.

[*][*] _Ligules none; flowers purplish._

P. VULGARIS, Desf. Rootstock very stout; leaves round-cordate, angulate-dentate and denticulate.--About Philadelphia. (Nat. from Eu.)

74. ARNICA, L.

Heads many-flowered, radiate; rays pistillate. Scales of the bell-shaped involucre lanceolate, equal, somewhat in 2 rows. Receptacle flat, fimbrillate. Achenes slender or spindle-shaped; pappus a single row of rather rigid and strongly roughened-denticulate bristles.--Perennial herbs, chiefly of mountains and cold northern regions, with simple stems, bearing single or corymbed large heads and opposite leaves. Flowers yellow. (Name thought to be a corruption of _Ptarmica_.)

1. A. Chamissonis, Less. Soft-hairy; _stem leafy_ (1--2 deg. high), bearing 1 to 5 heads; _leaves thin, veiny_, smoothish when old, toothed; the upper _ovate-lanceolate_, closely sessile, the lower narrower, tapering to a margined petiole; scales pointed; pappus almost plumose. (A. mollis, _Hook_.)--N. Maine, mountains of N. H. and northern N. Y., shores of L. Superior, and westward. July.

2. A. nudicaulis, Nutt. Hairy and rather glandular (1--3 deg. high); _leaves thickish, 3--5-nerved, ovate or oblong_, all sessile, mostly entire and near the root, the _cauline small_ and only one or two pairs; heads several, corymbed, showy.--Damp pine barrens, S. Penn. and southward. April, May.

75. SENECIO, Tourn. GROUNDSEL.

Heads many-flowered; rays pistillate, or none; involucre cylindrical to bell-shaped, simple or with a few bractlets at the base, the scales erect-connivent. Receptacle flat, naked. Pappus of numerous very soft and slender capillary bristles.--Herbs, in the United States, with alternate leaves and solitary or corymbed heads. Flowers chiefly yellow. (Name from _senex_, an old man, alluding to the hoariness of many species, or to the white hairs of the pappus.)

[*] _Root annual or in n. 3 biennial; heads several or many in a corymb; herbage glabrous or soon becoming so._

[+] _Rays none or minute._

S. VULGARIS, L. (COMMON GROUNDSEL.) Low, corymbosely branched, glabrate; leaves pinnatifid and toothed; clasping tips of involucral scales blackish; rays none.--Waste grounds. July--Sept. (Adv. from Eu.)

S. VISCOSUS, L. Coarser, viscid-pubescent and strong-scented; leaves 2-pinnatifid; scales not black-tipped; rays minute.--Waste grounds, coast of N. Eng. (Nat. from Eu.)

[+][+] _Heads conspicuously radiate._

1. S. lobatus, Pers. (BUTTER-WEED.) Rather tall; leaves somewhat fleshy, _lyrate or pinnate_, the divisions or leaflets crenate or cut-lobed, variable; heads small in a naked corymb; _rays 6--12, conspicuous_.--Wet grounds, N. Car. to S. Ill., Mo., and southward. April--July.

2. S. palustris, Hook. Annual or biennial, loosely woolly or glabrate; stem stout, 6'--2 deg. high; _leaves_ oblong-lanceolate, _irregularly toothed or laciniate_, the upper with a heart-shaped clasping base; _rays 20 or more_, short, pale yellow; pappus copious and becoming very long.--Wet ground, Iowa to N. Wisc., Minn., and northward. June. (Eu.)

[*][*] _Root perennial; heads small or middle-sized, in a naked corymb._

3. S. aureus, L. (GOLDEN RAGWORT. SQUAW-WEED.) _Smooth, or floccose-woolly when young_ (1--3 deg. high); leaves thin, the radical _simple and rounded_, the larger ones mostly heart-shaped, crenate-toothed, _long-petioled_; _lower stem-leaves lyrate_; upper ones lanceolate, cut-pinnatifid, sessile or partly clasping; corymb umbel-like; rays 8--12.--Common everywhere. May, June. Varies greatly.

Var. obovatus, Torr. & Gray. Root-leaves thicker, round-obovate with a cuneate or truncate base, or the earliest almost sessile in rosulate tufts. (S. Elliottii, _Torr. & Gray_.)--Open grounds, Can. to Ind. and Ga.

Var. Balsamitae, Torr. & Gray. Less glabrate; root-leaves oblong, spatulate, or lanceolate, narrowed to the petiole, serrate, the upper lyrate-pinnatifid; heads rather small and numerous.--Common.

4. S. tomentosus, Michx. (WOOLLY RAGWORT.) _Clothed with scarcely deciduous hoary wool_ (1--2 deg. high); _root-leaves oblong_, obtuse, crenate or entire, often large, on elongated stout petioles; the upper sessile, similar or lyrate-pinnatifid; corymb flat-topped; rays 12--15.--Del. and mountains of Penn. (_Pursh._), to Fla. and Ark. May.

5. S. canus, Hook. Usually low, persistently tomentose, rarely at all glabrate; leaves much smaller, spatulate to oblong, all entire or some cut-toothed or pinnatifid; achenes glabrous.--N. Minn., Dak., and westward.

6. S. integerrimus, Nutt. Woolly pubescent when young, soon glabrate and green; leaves oblong-lanceolate or oblong, entire or denticulate, the upper bract-like, attenuate from a broad base; heads rather large (6'' high), with green-tipped scales.--Sask. to Minn., and westward.

7. S. lugens, Richards. Like the last; leaves usually repand- or callous-denticulate; heads usually smaller, with mostly black-tipped scales.--Subarc. Amer. to New Mex., in the mountains; reported from Minn. and N. Iowa.

[*][*][*] _Root perennial; heads large and often solitary._

8. S. Pseudo-Arnica, Less. Loosely white-woolly, sometimes becoming glabrous; stem stout, 6--12' high, leafy to the top; leaves oblong, repand, tapering into a narrow petiole-like base; heads 1--4, over an inch in diameter; rays 20 or more, large.--Grand Manan Island, off Maine (_Prof. Verrill_), to Lab., and northward.

76. CACALIA, L. INDIAN PLANTAIN.

Heads 5--many-flowered; the flowers all tubular and perfect. Involucral scales in a single row, erect-connivent, with a few bractlets at the base. Receptacle naked. Corolla deeply 5-cleft. Achenes oblong, smooth; pappus of numerous soft capillary bristles.--Smooth and tall perennial herbs, with alternate often petioled leaves, and rather large heads, in flat corymbs. Flowers white or whitish. (An ancient name, of uncertain meaning.)

[*] _Involucre 25--30-flowered, with several bracts at its base; receptacle flat._

1. C. suaveolens, L. Stem grooved (3--5 deg. high); _leaves triangular-lanceolate, halberd-shaped_, pointed, serrate, those of the stem on winged petioles.--Rich woods, Conn. to Mich., Iowa, and southward; rare. Sept.

[*][*] _Involucre 5-leaved and 5-flowered, its bracts minute or none; receptacle bearing a more or less evident scale-like pointed appendage in the centre._

2. C. reniformis, Muhl. (GREAT INDIAN PLANTAIN.) Not glaucous; stem (4--9 deg. high) grooved and angled; _leaves green both sides, dilated fan-shaped, or the lowest kidney-form_ (1--2 deg. broad), _repand-toothed_ and angled, palmately veined, petioled; the teeth pointed; corymbs large.--Rich damp woods, N. J. to Ill., Minn., and southward along the mountains. Aug.

3. C. atriplicifolia, L. (PALE INDIAN P.) Glaucous; stem terete (3--6 deg. high); leaves _palmately veined and angulate-lobed_, the lower triangular-kidney-form or slightly heart-shaped, the upper rhomboid or wedge-form, _toothed_.--Rich woodlands, western N. Y. to Wisc., Minn., and southward. Aug.

4. C. tuberosa, Nutt. (TUBEROUS INDIAN P.) Stem angled and grooved (2--6 deg. high), from a thick or tuberous root; _leaves green both sides_, thick, strongly _5--7-nerved_; the lower _lance-ovate or oval_, nearly entire, tapering into long petioles; the upper on short margined petioles, sometimes toothed at the apex.--Wet prairies, etc., Ohio to Wisc., Minn., and southward. June.

77. ERECHTITES, Raf. FIREWEED.

Heads many-flowered; the flowers all tubular and fertile; the marginal pistillate, with a slender corolla. Scales of the cylindrical involucre in a single row, linear, acute, with a few small bractlets at the base. Receptacle naked. Achenes oblong, tapering at the end; pappus copious, of very fine and white soft hairs.--Erect and coarse annuals, of rank smell, with alternate simple leaves, and paniculate-corymbed heads of whitish flowers. (The ancient name of some species of Groundsel, probably called after _Erechtheus_.)

1. E. hieracifolia, Raf. (FIREWEED.) Often hairy; stem grooved (1--6 deg. high); leaves lanceolate or oblong, acute, cut-toothed, sessile, the upper auricled at base.--Moist woods; common, especially northward, and in recent clearings that have been burned over; whence the popular name. July--Sept.

78. ARCTIUM, L. BURDOCK.

Heads many-flowered; flowers all tubular, perfect and similar. Involucre globular; the imbricated scales coriaceous and appressed at base, attenuate to long stiff points with hooked tips. Receptacle bristly. Achenes oblong, flattened, wrinkled transversely; pappus short, of numerous rough bristles, separate and deciduous.--Coarse biennial weeds, with large unarmed and petioled leaves, and small solitary or clustered heads; flowers purple, rarely white. (Name probably from [Greek: a)/rktos], _a bear_, from the rough involucre.)

A. LAPPA, L. Stout, 1--3 deg. high; leaves roundish or ovate and mostly cordate, or lanceolate with cuneate base, smooth above, somewhat floccose-tomentose beneath, mostly sinuate-denticulate. (Lappa officinalis, _All._)--The several reputed species of the genus are scarcely distinguishable even as varieties. Var. MINUS, has rather small ovoid subracemose heads (about 8'' broad), on short peduncles, glabrous or somewhat cottony, the inner scales somewhat purplish-tipped, equalling the flowers; leaves occasionally cut-toothed. By roadsides; very common.--Var. MAJUS, with broader (1') green and glabrous subcorymbose rather long-pedunculate heads. Less frequent.--Var. TOMENTOSUM, a form of the last with more spherical webbed heads, with purplish scales shorter than the flowers. Rare.--July--Oct. (Nat. from Eu.)

79. CNICUS, Tourn. COMMON or PLUMED THISTLE.

Heads many-flowered; flowers all tubular, perfect and similar, rarely imperfectly dioecious. Scales of the ovoid or spherical involucre imbricated in many rows, tipped with a point or prickle. Receptacle thickly clothed with soft bristles or hairs. Achenes oblong, flattish, not ribbed; pappus of numerous bristles united into a ring at the base, plumose to the middle, deciduous.--Herbs, mostly biennial, with sessile alternate leaves, often pinnatifid, prickly. Heads usually large, terminal. Flowers reddish-purple, rarely white or yellowish; in summer. (Latin name of the Safflower, from the Greek [Greek: kne~kos].)

[*] _Scales of the involucre all tipped with spreading prickles._

C. LANCEOLATUS, Hoffm. (COMMON THISTLE.) Leaves decurrent on the stem, forming prickly lobed wings, pinnatifid, rough and bristly above, woolly with deciduous webby hairs beneath, prickly; flowers purple. (Cirsium, _Scop._)--Pastures and roadsides, everywhere, at the North. (Nat. from Eu.)

[*][*] _Heads leafy-bracteate at base_ (see also n. 8); _proper scales not prickly._

1. C. horridulus, Pursh. (YELLOW THISTLE.) Stem stout (1--3 deg. high), webby-haired when young; leaves partly clasping, green, soon smooth, lanceolate, pinnatifid, the short toothed and cut lobes very spiny with yellowish prickles; heads (1--11/2' broad) surrounded by leaf-like and very prickly bracts, which usually equal the narrow scales; flowers pale yellow or purple. (Cirsium, _Michx._)--Sandy fields, Mass. to Va., and southward, near the coast.

[*][*][*] _Scales appressed, the inner not at all prickly._

[+] _Leaves white-woolly beneath, and sometimes also above; outer scales successively shorter, and tipped with short prickles._

2. C. Pitcheri, Torr. _White-woolly throughout_, low; stem very leafy; _leaves all pinnately parted into rigid narrowly linear and elongated, sometimes again pinnatifid divisions_, with revolute margins; flowers cream-color. (Cirsium, _Torr. & Gray_.)--Sandy shores of Lakes Michigan, Huron, and Superior.

3. C. undulatus, Gray. _White-woolly throughout_, low and stout, leafy; _leaves lanceolate-oblong_, partly clasping, undivided, _undulate-pinnatifid_, or rarely pinnately parted, moderately prickly; flowers reddish-purple. (Cirsium, _Spreng._)--Islands of L. Huron to Minn., Kan., and westward. The heads vary much in size.

4. C. altissimus, Willd. Stem downy, branching (3--10 deg. high), _leafy quite to the heads; leaves_ roughish-hairy above, whitened with close wool beneath, _oblong-ovate to narrowly lanceolate, undivided, sinuate-toothed, undulate-pinnatifid, or twice pinnatifid_, the lobes or teeth weakly prickly; heads 11/2--2' high; flowers chiefly purple. (Cirsium, _Spreng._)--Fields and copses, Mass. to Minn., and southward.

Var. discolor, Gray. Stem 2--6 deg. high; leaves nearly all deeply pinnatifid into lanceolate or linear lobes. (Cirsium discolor, _Spreng._)--Common; N. Eng. to Ill., and southward.

5. C. Virginianus, Pursh. Stem woolly, slender, simple or sparingly branched (1--3 deg. high), the _branches or long peduncles naked; leaves lanceolate_, green above, whitened with close wool beneath, ciliate with prickly bristles, _entire or sparingly sinuate-lobed_, sometimes the lower deeply sinuate-pinnatifid; heads small; outer scales scarcely prickly; flowers purple. (Cirsium, _Michx._)--Woods and plains, Va., Ohio, and southward.

[+][+] _Leaves green both sides, or only with loose cobwebby hairs underneath; heads large; scales scarcely prickly-pointed._

6. C. muticus, Pursh. (SWAMP THISTLE.) _Stem tall_ (3--8 deg. high), angled, smoothish, panicled at the summit; branches sparingly leafy, bearing single or few rather large _heads; leaves_ somewhat hairy above, whitened _with loose webby hairs beneath_ when young, _deeply pinnatifid, the divisions lanceolate_, acute, cut-lobed, prickly-pointed; _scales of the webby and glutinous_ (sometimes glabrate) _involucre_ closely appressed, _pointless_ or barely mucronate; flowers purple. (Cirsium, _Michx._)--Swamps and low woods; common.

7. C. pumilus, Torr. (PASTURE THISTLE.) _Stem low_ and stout (1--2 deg. high), hairy, bearing 1--3 very large _heads_ (11/2' broad), which are often _leafy-bracted_ at the base; _leaves green_, lanceolate-oblong, partly clasping, _somewhat hairy, pinnatifid, with short and cut very prickly-margined lobes; outer scales prickly-pointed_, the inner very slender; flowers purple or rarely white (fragrant, 2' long). (Cirsium, _Spreng._)--Dry fields, Maine to Penn., near the coast.

[*][*][*][*] _Outer scales of the appressed involucre barely prickly-pointed; heads imperfectly dioecious, small and numerous._

C. ARVENSIS, Hoffm. (CANADA THISTLE.) Perennial, slender, 1--2 deg. high, the roots extensively creeping; leaves oblong or lanceolate, smooth, or slightly woolly beneath, sinuate-pinnatifid, prickly-margined; flowers rose-purple. (Cirsium, _Scop._)--Cultivated fields, pastures, and roadsides, common; a most troublesome weed, extremely difficult to eradicate. (Nat. from Eu.)

80. CARDUUS, Tourn. PLUMELESS THISTLE.

Bristles of the pappus naked (not plumose), merely rough or denticulate. Otherwise as in Cnicus. (The ancient Latin name.)

C. NUTANS, L. (MUSK THISTLE.) Biennial; leaves decurrent, sinuate, spiny; heads solitary, drooping; flowers purple.--Fields near Harrisburg, Pa., _Prof. Porter_. (Adv. from Eu.)

81. ONOPORDON, Vaill. COTTON or SCOTCH THISTLE.

Receptacle deeply honeycombed, not setose. Pappus not plumose. Otherwise as Cnicus.--Coarse, branching annuals, or biennials, with the stems winged by the decurrent base of the lobed and toothed somewhat prickly leaves. Heads large; flowers purple. (The ancient Greek name of the plant.)