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 p?????, _drooping_, and ????, _blossom_.)

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

1. P. crepidinea, Michx. Somewhat smooth; stem stout (5--9 high), bearing numerous nodding heads in loose cl.u.s.ters; 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 p.u.b.escent, strict; heads nearly erect, 12--15-flowered._

2. P. racemsa, Michx. Stem 2--5 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 cl.u.s.ters; 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 high, rough-p.u.b.escent, as well as the oval-oblong or broadly lanceolate toothed leaves; upper leaves not clasping; heads in small cl.u.s.ters; 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 high, prolonged into a naked and slender spiked raceme (1{}--2 long); heads cl.u.s.tered 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 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 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 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 cl.u.s.ters often sessile in most of the axils. (Nabalus na.n.u.s, _DC._)--Mountains of northern N. Eng. and N. Y., and northeastward.

8. P. altissima, L. Smooth; stem tall and slender (3--7 high); the heads in small axillary and terminal loose cl.u.s.ters 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. Bottii, Gray. Stem simple, dwarf (5--6' high), p.u.b.escent 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. LYG.o.deSMIA, 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 ?????, _a pliant twig_, and d?s?, _a bundle_, from the fascicled twiggy or rush-like stems.)

1. L. juncea, Don. Stems (1 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 t????, _to chew_, of no obvious application.)

1. T. cuspidatum, Pursh. Scape 1 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. glauc.u.m, Nutt. Scape 1--2 high; leaves linear to lanceolate, entire to dentate or laciniate; head often p.u.b.escent or villous; achene long-beaked.--Minn. to Neb. and southwestward.

94. TARaXAc.u.m, 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 ta??ss?, _to disquiet_ or _disorder_, in allusion to medicinal properties.)

T. OFFICINaLE, Weber. (COMMON DANDELION.) Smooth, or at first p.u.b.escent; 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 Taraxac.u.m, 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 p?????, _flame-colored_, and papp??, pappus.)

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

2. P. scapsus, 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 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.)

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

L. SCAROLA, L. (p.r.i.c.kLY LETTUCE.) Stem below spa.r.s.ely p.r.i.c.kly-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 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.