Part 40

O. ACANTHIUM, L. Stem (2--4 deg. high) and leaves cotton-woolly; scales linear-awl-shaped.--Roadsides and waste places in the Atlantic States; rather rare. July--Sept. (Adv. from Eu.)

82. CENTAUREA, L. STAR-THISTLE.

Heads many-flowered; flowers all tubular, the marginal often much larger (as it were radiate) and sterile. Receptacle bristly. Involucre ovoid or globose, imbricated, the scales margined or appendaged. Achenes obovoid or oblong, attached obliquely at or near the base; pappus setose or partly chaffy or none.--Herbs with alternate leaves and single heads. (Named from the _Centaur_, Chiron, famous for his skill in healing.)

[*] _Achenes terete, 10-dentate; pappus of 10 long bristles and 10 short inner ones._

C. BENEDICTA, L. Low branching annual, with clasping scarcely pinnatifid cut leaves, and large sessile leafy-bracted heads; flowers yellow. (Cnicus benedictus, _L._)--Roadsides and waste grounds, S. Atlantic States; rare. (Adv. from Eu.)

[*][*] _Achenes compressed or 4-angled; pappus very short or none._

C. CYANUS, L. (BLUEBOTTLE.) Scales of the globular involucre fringe-margined; _false rays large_; pappus very short; _leaves linear, entire_, or toothed at the base; root annual.--Roadsides, escaped from gardens. July.--Flowers blue, varying to purplish or white. (Adv. from Eu.)

C. NIGRA, L. (KNAPWEED.) Scales of the globular involucre appendaged, and with a black pectinately ciliate fringe; _rays wanting_; pappus very short; _leaves lanceolate_, entire, or the lower lyrate-toothed, rough; root perennial.--Waste places, E. New Eng. Aug.--Flowers purple. (Adv. from Eu.)

C. CALCITRAPA, L. (STAR-THISTLE.) Stem diffusely much branched; _leaves pinnately lobed_ or spinulose-toothed; heads sessile, the middle _scales of the ovoid involucre spiny_; pappus none; flowers purple; root annual.--Seaports, N. Y., and southward. (Adv. from Eu.)

C. JACEA, L. Like the last; heads rather larger, the brownish scale-appendages lacerate; rays conspicuous, palmate.--Charlotte, Vt. (_Pringle_); near N. Y., etc., on ballast. (Nat. from Eu.)

83. LAMPSANA, Tourn. NIPPLE-WORT.

Heads 8--12-flowered. Scales of the cylindrical involucre 8, erect, in one row. Receptacle naked. Achenes oblong; pappus none.--Slender branching annuals, with angled or toothed leaves, and loosely panicled small heads; flowers yellow. (The [Greek: lampsa/ne] of Dioscorides was evidently a wild Mustard.)

L. COMMUNIS, L. Nearly smooth, 1--2 deg. high; lower leaves ovate, sometimes lyre-shaped.--Roadsides, N. Eng. to N. Y. and Penn. (Nat. from Eu.)

84. KRIGIA, Schreber. DWARF DANDELION.

Heads several--many-flowered. Involucral scales several, in about 2 rows, thin. Achenes short and truncate, top-shaped or columnar, terete or angled; pappus double, the outer of thin pointless chaffy scales, the inner of delicate bristles.--Small herbs, branched from the base; the leaves chiefly radical, lyrate or toothed; the small heads terminating the naked scapes or branches. Flowers yellow. (Named after _D. Krieg_, an early German botanical collector in this country.)

Sec. 1. KRIGIA proper. _Achenes turbinate, 5-angled; pappus of 5--7 short roundish chaff and as many alternating bristles. Annual._

1. K. Virginica, Willd. Stems or scapes several (1--10' high), becoming branched and leafy; earlier leaves roundish and entire, the others narrower and often pinnatifid.--New Eng. to Minn., and southward. April--Aug.

Sec. 2. CYNTHIA. _Achenes more slender; pappus of 10--15 small oblong chaff and 15--20 bristles. Perennial._

2. K. Dandelion, Nutt. Roots slender, tuberiferous; _scapes leafless_, 6--18' high; leaves varying from spatulate-oblong to linear-lanceolate, entire or few-lobed. (Cynthia, _DC._)--Moist ground, Md. to Ky., and southward. March--July.

3. K. amplexicaulis, Nutt. _Roots fibrous; stem-leaves 1--3_, oblong or oval, clasping, mostly entire; the radical ones on short winged petioles, often toothed, rarely pinnatifid; peduncles 2--5. (Cynthia Virginica, _Don._)--Moist banks, Conn. to Minn., and southward. June.--Stem 1--2 deg. high.

85. CICHORIUM, Tourn. SUCCORY or CHICORY.

Heads several-flowered. Involucre double, herbaceous, the inner of 8--10 scales, the outer 5, short and spreading. Achenes striate; pappus of numerous small chaffy scales, forming a short crown.--Branching perennials, with deep roots; the sessile heads 2 or 3 together, axillary and terminal. Flowers bright blue, varying to purple or pink, showy. (Altered from the Arabian name of the plant.)

C. INTYBUS, L. Stem-leaves oblong or lanceolate, partly clasping, the lowest runcinate, those of the rigid flowering branches minute.--Roadsides; N. Eng. to Iowa and Minn. July--Oct. (Nat. from Eu.)

86. TRAGOPOGON, L. GOAT'S-BEARD.

Heads many-flowered. Involucre simple, of several erect lanceolate attenuate equal scales. Achenes narrowly fusiform, 5--10-ribbed, long-beaked; pappus of numerous long-plumose bristles.--Stout glabrous biennials or perennials, with entire grass-like clasping leaves and large solitary heads of yellow or purple flowers. (Name from [Greek: tra/gos], _goat_, and [Greek: po/gon], _beard_.)

T. PORRIFOLIUS, L. (SALSIFY. OYSTER-PLANT.) Stem 2--3 deg. high; peduncle thickened and fistulous below the head; flowers purple; achenes and pappus 3' long.--Sparingly escaped from cultivation. (Nat. from Eu.)

T. PRATENSIS, L. (GOAT'S-BEARD.) Very similar; leaves somewhat broader at base; peduncle little thickened; flowers yellow.--Fields, etc., N. Eng. to N. J. and Minn. (Nat. from Eu.)

87. LEONTODON, L., Juss. HAWKBIT.

Heads many-flowered. Involucre scarcely imbricated, but with several bractlets at the base. Achenes spindle-shaped, striate, all alike; pappus persistent, composed of plumose bristles which are enlarged and flattened toward the base.--Low and stemless perennials, with toothed or pinnatifid root-leaves, and scapes bearing one or more yellow heads. (Name from [Greek: le/on], _a lion_, and [Greek: o)dou/s], _a tooth_, in allusion to the toothed leaves.)--The following belongs to the subgenus OPORINIA, with a tawny pappus of a single row of equal bristles.

L. AUTUMNALIS, L. (FALL DANDELION.) Leaves laciniate-toothed or pinnatifid, somewhat pubescent; scape branched, 5--15' high; peduncles thickened at the summit, scaly-bracteate.--Meadows and roadsides; N. Eng. to Penn. June--Nov. (Nat. from Eu.)

88. PICRIS, L.

Heads many-flowered, terminating leafy stems. Outer scales loose or spreading. Achenes terete, with 5--10 rugose ribs; pappus of 1 or 2 rows of plumose bristles.--Coarse rough-bristly annuals or biennials, with yellow flowers. (The Greek name of some allied bitter herb, from [Greek: pikro/s], _bitter_.)

P. HIERACIOIDES, L. Rather tall, corymbosely branched, the bristles somewhat barbed at tip; leaves lanceolate or broader, clasping, irregularly toothed; achenes oblong, with little or no beak.--Sparingly introduced. (Nat. from Eu.)

89. HIERACIUM, Tourn. HAWKWEED.

Heads 12--many-flowered. Involucre more or less imbricated. Achenes short, oblong or columnar, striate, not beaked; pappus a single row of tawny and fragile capillary rough bristles.--Hispid or hirsute and often glandular perennials, with entire or toothed leaves, and single or panicled heads of mostly yellow flowers; summer and early autumn. (Name from [Greek: i(e/rax], _a hawk_.)

Sec. 1. _Involucre not much imbricate, scarcely calyculate; achenes oblong; pappus not copious._

H. AURANTIACUM, L. Low, long-hirsute, above hispid and glandular, the involucral hairs dark; leaves all near the base of the simple peduncle; heads clustered; flowers deep orange to flame-color.--Roadsides and fields; N. Eng. to N. Y. (Nat. from Eu.)

H. PRAEALTUM, Vill. Glaucous, 2 deg. high, only the base and lanceolate leaves hairy; heads in an open cyme; flowers yellow.--N. New York (_Ward_). (Nat. from Eu.)

Sec. 2. _Heads large; involucre irregularly imbricated; achenes columnar; pappus copious, unequal._

H. MURORUM, L. Stem scape-like, low; leaves oval or oblong, obtuse, toothed toward the subcordate base; heads few, dark-glandular.--Open woods near Brooklyn, N. Y. (Nat. from Eu.)

1. H. Canadense, Michx. Stems simple, leafy, corymbed at the summit (1--3 deg. high); leaves sessile, lanceolate or ovate-oblong, acute, remotely and very coarsely toothed, somewhat hairy, the uppermost slightly clasping.--Dry woods, N. Eng. to Penn., Minn., and northward.

Sec. 3. _Heads small; involucre cylindrical, scarcely imbricated._

[*] _Achenes columnar, not attenuate upward when mature; panicle not virgate._

2. H. paniculatum, L. _Stem slender, leafy, diffusely branched_, hairy only below (1--3 deg. high); leaves lanceolate, acute at both ends, slightly toothed, smooth; _heads_ (very small) _in a loose panicle_, on slender and diverging pedicels, _12--20-flowered; achenes short_.--Open woods; rather common.

3. H. venosum, L. (RATTLESNAKE-WEED.) Stem or _scape_ (1--2 deg. high) _naked or with a single leaf, smooth and slender, forking above into a spreading loose corymb_; leaves all radical or near the base, obovate or oblong, nearly entire, scarcely petioled, thin and pale, purplish and glaucous underneath (often hairy along the midrib), marked above with purple veins; pedicels very slender; involucre 12--35-flowered; _achenes linear_.--Dry plains and pine woods; common from the Atlantic to Minn. and Iowa.

4. H. Marianum, Willd. _Somewhat leafy_, 2--3 deg. high, hairy below; leaves obovate-oblong, narrowed below, _the radical petiolate, rarely purplish-veiny_; heads 20--40-flowered in a very open cymose panicle, _the slender inflorescence commonly whitish-tomentulose and sparingly glandular-hispid_.--Open woods and clearings; R. I. to western N. Y., and southward.--Var. SPATHULATUM, Gray, a mountain form with leaves all or mainly radical and very hairy. On Two-top Mountain, Penn.

5. H. scabrum, Michx. Stem rather stout (1--3 deg. high), leafy, _rough-hairy_, the stiff panicle at first racemose, at length rather corymbose; the thickish pedicels and the hoary 40--50-flowered involucre densely clothed with dark glandular bristles; leaves obovate or oval, nearly entire, hairy.--Dry open woods; common.

[*][*] _Achenes tapering upward; heads 15--30-flowered in a narrow or virgate panicle._

6. H. Gronovii, L. (HAIRY H.) Stem wand-like, mostly simple (1--3 deg. high), _leafy and very hairy below, naked above_ and forming a long and narrow panicle; leaves oblong or obovate, nearly entire, hairy; slender peduncles and involucre sparingly glandular-bristly; _achenes with a very taper summit_.--Dry sterile soil; common, especially southward.

7. H. longipilum, Torr. (LONG-BEARDED H.) Stem wand-like, simple, stout (2--3 deg. high), _very leafy toward the base, naked above_, and bearing a small racemed panicle; the lower portion and both sides of the oblong-lanceolate or spatulate entire leaves thickly _clothed with very long and upright bristles_ (often 1' long); peduncles and involucre glandular-bristly; _achenes narrowed at the apex_.--Prairies, Mich. to Minn., and southwestward.

90. CREPIS, L.

Involucre few--many-flowered, commonly of a single row of equal scales, often becoming thickened at base. Pappus copious, white and soft. Annuals or biennials, not pilose. Otherwise as Hieracium. (The Greek name of some plant, from [Greek: krepi/s], _a sandal_.)

C. BIENNIS, L. Somewhat pubescent, 2 deg. high, leafy; leaves runcinate-pinnatifid; heads rather large, corymbose; achenes oblong, glabrous.--Vt., Mass.; rare. (Nat. from Eu.)

C. TECTORUM, L. Slender, branching from the base, 1 deg. high; leaves narrow, runcinate; heads small, in a loose panicle; achenes fusiform, the ribs scabrous.--In fields, Lansing, Mich., and on ballast. (Nat. from Eu.)

91. PRENANTHES, Vaill. RATTLESNAKE-ROOT.

Heads 5--30-flowered. Involucre cylindrical, of 5 to 14 linear scales in a single row, and a few small bractlets at base. Achenes short, linear-oblong, striate or grooved, not contracted at the apex. Pappus of copious straw-color or brownish and rough capillary bristles.--Perennial herbs, with upright leafy stems arising from spindle-shaped (extremely bitter) tubers, very variable leaves, and racemose-panicled mostly nodding heads. Flowers greenish-white or yellowish, often tinged with purple; late summer and autumn. Our species belong to the subgenus _Nabalus_. The original European species has soft white pappus. (Name from [Greek: prene/s], _drooping_, and [Greek: a)/nthe], _blossom_.)

[*] _Heads rather broad, 25--35-flowered, in a corymbose panicle._

1. P. crepidinea, Michx. Somewhat smooth; stem stout (5--9 deg. high), bearing numerous nodding heads in loose clusters; leaves large (6--12' long), broadly triangular-ovate or halberd-form, strongly-toothed, contracted into winged petioles; pappus brown. (Nabalus, _DC._)--Rich soil, Penn. and western N. Y. to Minn., and southward.--Flowers cream-color.

[*][*] _Heads narrow, 8--15-flowered, in a long raceme-like or thyrsoid inflorescence; stems simple; cauline leaves sessile; pappus straw-color._

[+] _Inflorescence pubescent, strict; heads nearly erect, 12--15-flowered._

2. P. racemosa, Michx. Stem 2--5 deg. high, smooth and glaucous, as well as the oval or oblong-lanceolate denticulate leaves; the lower tapering into winged petioles (rarely cut-pinnatifid), the upper partly clasping; heads in crowded clusters; flowers purplish. (Nabalus, _DC._)--Plains, N. Maine to N. J., Mo., and northward.--Var. PINNATIFIDA, Gray, the leaves all lyrately pinnatifid. Hackensack marshes, N. J.

3. P. aspera, Michx. Stem 2--4 deg. high, rough-pubescent, as well as the oval-oblong or broadly lanceolate toothed leaves; upper leaves not clasping; heads in small clusters; flowers larger, cream-color. (Nabalus asper, _Torr. & Gray_.)--Dry prairies and barrens, Ohio to Iowa, and southward.

[+][+] _Whole plant glabrous; heads nodding, 8--12-flowered; thyrse looser._

4. P. virgata, Michx. (SLENDER RATTLESNAKE-ROOT.) Slightly glaucous; stem 2--4 deg. high, prolonged into a naked and slender spiked raceme (1{1/2}--2 deg. long); heads clustered and mostly unilateral; leaves lanceolate, acute, closely sessile, the upper reduced to bracts, the lower toothed or pinnatifid; involucre (purplish) of about 8 scales. (Nabalus, _DC._)--Sandy pine barrens, N. J. to Va., and southward.

5. P. Mainensis, Gray. Stem 2 deg. high, leafy; leaves as in n. 2, but the radical ovate and more abruptly narrowed to the short petiole; heads persistently drooping on slender pedicels.--St. John's River, N. Maine (_Pringle_). Perhaps a hybrid between n. 2 and 7.

[*][*][*] _Heads 5--18-flowered, racemose or paniculate, commonly pendulous; leaves variable, mostly petiolate, the lower cordate or truncate or hastate at base._

[+] _Involucre cylindrical; scales scarious-margined, the outer very short, appressed._

[++] _Pappus reddish-brown; stem tall, generally purplish._

6. P. alba, L. (WHITE LETTUCE. RATTLESNAKE-ROOT.) Smooth and glaucous (2--4 deg. high); stem corymbose-panicled at the summit; leaves angulate or triangular-halberd-form, sinuate-toothed or 3--5-cleft, the uppermost oblong and undivided; involucre (purplish) of about 8 scales, 8--12-flowered. (Nabalus, _Hook_.)--Borders of rich woods; common, especially northward.

[++][++] _Pappus dirty straw-color or whitish; leaves very variable._

7. P. serpentaria, Pursh. (LION'S-FOOT. GALL-OF-THE-EARTH.) Nearly smooth; stem corymbose-panicled at the summit, commonly 2 deg. high; leaves mostly deltoid, roughish; the lower variously 3--7-lobed, on margined petioles; the upper oblong-lanceolate, mostly undivided, nearly sessile; involucre (greenish, rarely purplish, sometimes slightly bristly) of about 8 scales, 8--12-flowered; flowers purplish, greenish white, or cream-color. (Nabalus Fraseri, _DC._)--Dry sandy or sterile soil, New Eng. to Va., and southward.

Var. nana, Gray. Stem more simple and strict, 6--16' high, smooth and glabrous; inflorescence contracted, the clusters often sessile in most of the axils. (Nabalus nanus, _DC._)--Mountains of northern N. Eng. and N. Y., and northeastward.

8. P. altissima, L. Smooth; stem tall and slender (3--7 deg. high); the heads in small axillary and terminal loose clusters forming a long and wand-like leafy panicle; leaves membranaceous, all petioled, ovate, heart-shaped, or triangular, and merely toothed or cleft, with naked or winged petioles, or frequently 3--5-parted, with the divisions entire or again cleft; involucre slender (greenish), of 5 scales, 5--6-flowered. (Nabalus, _Hook._)--Rich moist woods; N. Eng. to Minn., and southward in the mountains to Ga.

[+][+] _Involucre campanulate-oblong; secondary basal scales 2--3, linear, loose._

9. P. Boottii, Gray. Stem simple, dwarf (5--6' high), pubescent at the summit; the heads in an almost simple raceme; lowest leaves halberd-shaped or heart-shaped, the middle oblong, the upper lanceolate, nearly entire, tapering into a margined petiole; involucre (livid) 10--18-flowered, the proper scales 10--15, very obtuse; pappus straw-color.--Alpine region, mountains of Maine, N. H., and N. New York.

92. LYGODESMIA, Don.

Heads and flowers (5--10) nearly as in Nabalus; the cylindrical involucre more elongated, and the achenes long and slender, tapering at the summit; pappus whitish.--Smooth, often glaucous, low perennials, with single erect heads of rose-purple flowers terminating almost leafless or rush-like stems or branches. (Name composed of [Greek: ly/gos], _a pliant twig_, and [Greek: de/sme], _a bundle_, from the fascicled twiggy or rush-like stems.)

1. L. juncea, Don. Stems (1 deg. high) tufted, branched, striate; lower leaves lance-linear, 1--2' long, rigid, the upper awl-shaped and minute; heads 5-flowered.--St. Croix River, Wisc., to Kan., and westward. July.

93. TROXIMON, Nutt.

Head large, solitary, many-flowered. Scales of the bell-shaped involucre ovate or lanceolate, pointed, loosely imbricated in 2 or 3 rows. Achenes smooth, 10-ribbed, with distinct beak or none, pappus longer than the achene, white, of copious and unequal rigid capillary bristles.--Perennial scapose herbs, with elongated linear tufted root-leaves, and yellow flowers. (Name probably from [Greek: tro/go], _to chew_, of no obvious application.)

1. T. cuspidatum, Pursh. Scape 1 deg. high, from a thickened caudex, leaves lanceolate, elongated, tapering to a sharp point, entire, woolly on the margins; scales of the involucre lanceolate, sharp-pointed, achene beakless.--Prairies, Wisc., N. Ill., and westward. April, May.

2. T. glaucum, Nutt. Scape 1--2 deg. high; leaves linear to lanceolate, entire to dentate or laciniate; head often pubescent or villous; achene long-beaked.--Minn. to Neb. and southwestward.

94. TARAXACUM, Haller. DANDELION.

Head many-flowered, large, solitary on a slender hollow scape. Involucre double, the outer of short scales; the inner of long linear scales, erect in a single row. Achenes oblong-ovate to fusiform, 4--5-ribbed, the ribs roughened, the apex prolonged into a very slender beak, bearing the copious soft and white capillary pappus.--Perennials or biennials; leaves radical, pinnatifid or runcinate; flowers yellow. (Name from [Greek: tara/sso], _to disquiet_ or _disorder_, in allusion to medicinal properties.)

T. OFFICINALE, Weber. (COMMON DANDELION.) Smooth, or at first pubescent; outer involucre reflexed. (T. Dens-leonis, _Desf._)--Pastures and fields everywhere. Indigenous forms occur northward and in the Rocky Mountains. April--Sept.--After blossoming, the inner involucre closes, and the slender beak elongates and raises up the pappus while the fruit is forming; the whole involucre is then reflexed, exposing to the wind the naked fruits, with the pappus displayed in an open globular head. (Eu.)

95. PYRRHOPAPPUS, DC. FALSE DANDELION.

Heads, etc., nearly as in Taraxacum, but the soft pappus reddish or rusty-color, and surrounded at base by a soft-villous ring.--Mostly annual or biennial herbs, scapose or often branching and leafy below. Heads solitary, terminating the naked summit of the stem or branches. Flowers deep yellow. (Name composed of [Greek: pyr)r(o/s], _flame-colored_, and [Greek: pappo/s], pappus.)

1. P. Carolinianus, DC. Annual or biennial, stem branching (1--2 deg. high); leaves oblong or lanceolate, entire, cut, or pinnatifid, the stem-leaves partly clasping.--Sandy fields, from Maryland southward. April--July.

2. P. scaposus, DC. Low, scapose, perennial by roundish tubers; leaves all radical, pinnatifid.--Prairies; Kan. to Tex.

96. CHONDRILLA, Tourn.

Heads few-flowered. Involucre cylindrical, of several narrow linear equal scales, and a row of small bractlets at base. Achenes terete, several-ribbed, smooth below, roughened at the summit by little scaly projections, from among which springs an abrupt slender beak; pappus of copious very fine and soft capillary bristles, bright white.--Herbs of the Old World, with wand-like branching stems, and small heads of yellow flowers. (A name of Dioscorides for some plant which exudes a gum.)

C. JUNCEA, L. Biennial, bristly-hairy below, smooth above (1--3 deg. high); root-leaves runcinate; stem-leaves few and small, linear; heads scattered on nearly leafless branches, 6--8'' long.--Fields and roadsides, abundant in Md. and northern Va. Aug. (Adv. from Eu.)

97. LACTUCA, Tourn. LETTUCE.

Heads several--many-flowered. Involucre cylindrical or in fruit conical; scales imbricated in 2 or more sets of unequal lengths. Achenes flat (obcompressed, parallel to the scales), abruptly contracted into a beak, which is dilated at the apex, bearing a copious and fugacious very soft and white capillary pappus, its bristles falling separately.--Leafy-stemmed herbs, with panicled heads; flowers of variable color, produced in summer and autumn. (The ancient name of the Lettuce, _L. sativa_; from _lac_, milk, in allusion to the milky juice.)

Sec. 1. SCARIOLA. _Achenes very flat, orbicular to oblong, 1-nerved on each face, with a filiform beak; biennial or annual; cauline leaves sagittate-clasping._

L. SCARIOLA, L. (PRICKLY LETTUCE.) Stem below sparsely prickly-bristly, as also the midrib on the lower face of the oblong or lanceolate spinulose-denticulate vertical leaves; panicle narrow; heads small, 6--12-flowered; achenes striate.--Waste grounds and roadsides, Atlantic States to Mo. and Minn. (Adv. from Eu.)

1. L. Canadensis, L. (WILD LETTUCE.) Mostly tall (4--9 deg. high), very leafy, smooth or nearly so, glaucous; leaves 6--12' long, pale beneath, mostly sinuate-pinnatifid, the upper lanceolate and entire (rarely all but the lower narrow and entire); heads about 20-flowered, 3--6'' long, numerous, in long and narrow or diffuse panicles; flowers pale yellow; achene oval, rather longer than the beak.--Rich damp soil, borders of fields or thickets; common.

2. L. integrifolia, Bigel. Less leafy, 3--4 deg. high, loosely branched above or heads loosely panicled; leaves undivided, oblong-lanceolate, pointed, denticulate or entire; flowers yellow or purplish. (L. Canadensis, var. integrifolia, _Torr. & Gray_.)--N. Eng. to Ill., and southward.

3. L. hirsuta, Muhl. Rather few-leaved, 2--3 deg. high, commonly hirsute at base; leaves hirsute both sides or only on the midrib, mostly runcinate-pinnatifid; heads in a loose open panicle; achenes oblong-oval, about as long as the beak; flowers yellow-purple, rarely whitish. (L. Canadensis, var. sanguinea, _Torr. & Gray_.)--E. Mass. to Minn., and southward.

4. L. Ludoviciana, DC. Glabrous, leafy, 2--5 deg. high; leaves oblong, sinuate-pinnatifid and spinulosely dentate, ciliate; heads in an open panicle; involucre more imbricate; flowers yellow.--Minn., Iowa, and southwestward.

Sec. 2. LACTUCASTRUM. _Achenes flat, lanceolate-oblong, tapering to a short slender beak; perennial; flowers blue._