(S??f???, the ancient name of some resinous plant, transferred by Linnaeus to this American genus.)

[*] _Stem terete, alternate-leaved (root very large and thick)._

1. S. laciniatum, L. (ROSIN-WEED. COMPa.s.s-PLANT.) _Rough-bristly throughout_, stem stout (3--12 high), leafy; _leaves pinnately parted_, petioled but dilated and clasping at the base; _their divisions lanceolate or linear_, acute, _cut-lobed or pinnatifid_, rarely entire; heads few (1--2' broad), sessile or short-peduncled along the naked summit; _scales ovate, tapering into long and spreading rigid points_; achenes broadly winged and deeply notched, 6" long.--Prairies, Mich. to Dak., and southward. July.--Lower and root-leaves vertical, 12--30'

long, ovate in outline; on the wide open prairies disposed to present their edges north and south; hence called _Compa.s.s-Plant_.

2. S. terebinthinaceum, L. (PRAIRIE DOCK.) _Stem smooth, slender_ (4--10 high), panicled at the summit and bearing several or many, large heads, leafless except toward the base; _leaves ovate_ and ovate-oblong, somewhat heart-shaped, _serrate-toothed_, thick, rough, especially beneath (1--2 long, on slender petioles); _scales roundish, obtuse_, smooth; achenes narrowly winged, slightly notched and 2-toothed.--Var.

PINNATiFIDUM, Gray, has the leaves deeply cut or pinnatifid, but varies into the ordinary form.--Prairies and oak-openings, Ohio and Mich. to Minn., and southward. July--Sept.

[*][*] _Stem terete or slightly 4-angled, leafy; leaves undivided (not large), some opposite._

3. S. trifoliatum, L. _Stem smooth, often glaucous_, rather slender (4--7 high), branched above; stem-_leaves lanceolate, pointed, entire_ or scarcely serrate, rough, _short-petioled, in whorls of 3 or 4_, the uppermost opposite; heads loosely panicled; achenes rather broadly winged, and sharply 2-toothed at the top.--Dry plains and banks, Penn.

to Ohio, and southward. Aug.

4. S. Asteriscus, L. _Stem hispid_ (2--4 high); _leaves opposite, or the lower rarely in whorls of 3, the upper alternate, oblong or oval-lanceolate, coa.r.s.ely toothed_, rarely entire, _rough-hairy_, the lower short-petioled; heads nearly solitary (large), squarrose; achenes obovate, winged, 2-toothed, the teeth usually awn-like.--Dry sandy soil, Va. and southward.

5. S. integriflium, Michx. _Stem smooth or rough_, rather stout (2--4 high), rigid, 4-angular and grooved; _leaves all opposite, rigid, lanceolate-ovate_, entire or denticulate, tapering to a sharp point _from a roundish heart-shaped and partly clasping base_, rough-p.u.b.escent or nearly smooth, thick (3--5' long); heads in a close forking corymb, short-peduncled; achenes broadly winged, deeply notched.--Prairies, Mich. to Minn., and southward. Aug.

[*][*][*] _Stem square; leaves opposite, connate (thin and large, 6--15'

long)._

6. S. perfoliatum, L. (CUP-PLANT.) Stem stout, often branched above (4--8 high), leafy; leaves ovate, coa.r.s.ely toothed, the upper united by their bases and forming a cup-shaped disk, the lower abruptly narrowed into winged petioles which are connate by their bases; heads corymbose; scales ovate; achenes winged and variously notched.--Rich soil along streams, Mich. to Minn., and southward; common. Also escaped from gardens eastward. July.

38. BERLANDIeRA, DC.

With the characters of Silphium, but the 5--12 fertile ray-flowers in a single series. Involucral scales in about 3 series, thinner, the inner dilated obovate, exceeding the disk, the outer smaller and more foliaceous. Achenes obovate, not winged nor notched at the apex, and without pappus, deciduous with the subtending scale and 2 or 3 of the inner chaff.--Alternate-leaved perennials of the southern and southwestern States; head pedunculate. (Named for _J. L. Berlandier_, a Swiss botanist who collected in Texas and Mexico.)

1. B. Texana, DC. Hirsute-tomentose or villous, 2--3 high, very leafy; leaves crenate, the radical oblong, petiolate, the cauline oblong-cordate to subcordate-lanceolate, the upper closely sessile; heads somewhat cymose, ' broad.--S. W. Mo. to La. and Tex.

39. CHRYSoGONUM, L.

Heads many-flowered, radiate; the rays about 5, pistillate and fertile; the disk-flowers perfect but sterile. Involucre of about 5 outer leaf-like oblong scales, which exceed the disk, and as many interior shorter and chaff-like concave scales. Receptacle flat, with a linear chaff to each disk-flower. Achenes all in the ray, obovate, obcompressed, 4-angled, each one partly enclosed by the short scale of the involucre behind it; pappus a small chaffy crown, 2--3-toothed, and wanting on the inner side.--A hairy, perennial herb, with opposite long-petioled leaves, and solitary long-peduncled heads of yellow flowers, nearly stemless when it begins to flower, the flowerless shoots forming runners. (The Greek name of some plant, composed of ???s??, _golden_, and ????, _knee_.)

1. C. Virginianum, L. Usually low (2--15' high); leaves ovate, mostly obtuse, crenate, rarely somewhat cordate, or the radical obovate with cuneate base; rays ' long.--Dry soil, from southern Penn. to Fla.

May--Aug.--Var. DENTaTUM, Gray; leaves deltoid-ovate, acute, coa.r.s.ely dentate-serrate; involucral scales more acute.--High Island at the Falls of the Potomac.

40. ENGELMaNNIA, Torr. & Gray.

Heads and flowers of the preceding genera. Rays 8--10. Involucre of about 10 outer loose foliaceous scales, more or less dilated and coriaceous at base, and several firm-coriaceous, oval or obovate, concave inner ones with short abrupt green tips. Chaff of the flat receptacle firm and persistent. Achenes flat, obovate, wingless, tardily deciduous with the attached scale and chaff; pappus a firm scarious hispid crown, more or less lobed.--A coa.r.s.e hispid perennial, with alternate deeply pinnatifid leaves, and somewhat paniculately disposed heads on slender naked peduncles; flowers yellow. (Named for the eminent botanist, _Dr. George Engelmann_.)

1. E. pinnatifida, Torr. & Gray. Stems 1--2 high; heads ' broad, and rays ' long.--Central Kan. to La., and westward.

41. PARTHeNIUM, L.

Heads many-flowered, inconspicuously radiate; ray-flowers 5, with very short and broad obcordate ligules not projecting beyond the woolly disk, pistillate and fertile; disk-flowers staminate with imperfect styles, sterile. Involucre hemispherical, of 2 ranks of short ovate or roundish scales. Receptacle conical, chaffy. Achenes only in the ray, obcompressed, surrounded by a slender callous margin, crowned with the persistent ray-corolla and a pappus of 2 small chaffy scales.--Leaves alternate. Heads small, corymbed; the flowers whitish. (An ancient name of some plant, from pa??????, _virgin_.)

1. P. integriflium, L. Rough-p.u.b.escent perennial (1--3 high); leaves oblong or ovate, crenate-toothed, or the lower (3--6' long) cut-lobed below the middle; heads many in a very dense flat corymb.--Dry soil, Md.

to Ill., Minn., and southward. June--Aug.

42. VA, L. MARSH ELDER. HIGHWATER-SHRUB.

Heads several flowered, not radiate; the pistillate fertile and the staminate sterile flowers in the same heads, the former few (1--5) and marginal, with a small tubular or no corolla; the latter with a funnel-form 5-toothed corolla. Anthers nearly separate. Scales of the involucre few, roundish. Receptacle small, with narrow chaff among the flowers. Achenes obovoid or lenticular, pappus none.--Herbaceous or shrubby coa.r.s.e plants, with thickish leaves, the lower opposite, and small nodding greenish-white heads of flowers; in summer and autumn.

(Name of unknown derivation.)

-- 1. _Heads spicate or racemose in the axils of leaves or leaf-like bracts; fertile flowers with evident corolla._

1. I. frutescens, L. _Shrubby at the base, nearly smooth_ (3--8 high); leaves oval or lanceolate, coa.r.s.ely and sharply toothed, rather fleshy, the upper reduced to linear bracts, in the axils of which the heads are disposed, in leafy panicled racemes; fertile flowers and scales of the involucre 5.--Salt marshes, coast of Ma.s.s. to Va. and southward.

2. I. ciliata, Willd. _Annual_ (2--6 high), _rough and hairy; leaves_ ovate, pointed, coa.r.s.ely toothed, _downy beneath, on slender ciliate petioles_; heads in dense spikes, with conspicuous ovate-lanceolate rough-ciliate bracts; scales of the involucre and fertile flowers 3--5.--Moist ground, from Ill. southward.

-- 2. CYCLACHae'NA. _Heads in panicled spikes, scarcely bracteate; corolla of the 5 fertile flowers a mere rudiment or none._

3. I. xanthiiflia, Nutt. Annual, tall, roughish; leaves nearly all opposite, h.o.a.ry with minute down, ovate, rhombic, or the lowest heart-shaped, doubly or cut-toothed, or obscurely lobed; heads small, crowded, in axillary and terminal panicles.--N. W. Wisc. to Minn., Kan., and westward.

43. AMBRSIA, Tourn. RAGWEED.

Sterile and fertile flowers occupying different heads on the same plant; the fertile 1--3 together and sessile in the axil of leaves or bracts, at the base of the racemes or spikes of sterile heads. Sterile involucres flattish or top-shaped, of 7--12 scales united into a cup, containing 5--20 funnel-form staminate flowers, with slender chaff intermixed, or none. Anthers almost separate. Fertile involucre (fruit) oblong or top-shaped, closed, pointed, resembling an achene (usually with 4--8 tubercles or horns near the top in one row), and enclosing a single flower which consists of a pistil only; the elongated style-branches protruding. Achenes ovoid; pappus none.--Coa.r.s.e homely weeds, with opposite or alternate lobed or dissected leaves, and inconspicuous greenish flowers, in late summer and autumn; ours annuals, except the last. (The Greek and later Latin name of several plants, as well as of the food of the G.o.ds.)

-- 1. _Sterile heads sessile in a dense spike, the top-shaped involucre extended on one side into a large, lanceolate, hooded, bristly-hairy tooth or appendage; fertile involucre oblong and 4-angled._

1. A. bidentata, Michx. Hairy (1--3 high), very leafy; leaves alternate, lanceolate, partly clasping, nearly entire, except a short lobe or tooth on each side near the base; fruit with 4 stout spines and a central beak.--Prairies of Ill., Mo., and southward.

-- 2. _Sterile heads in single or panicled racemes or spikes, the involucre regular._

[*] _Leaves opposite, only once lobed; sterile involucre 3-ribbed on one side._

2. A. trifida, L. (GREAT RAGWEED.) Stem stout (3--12 high), rough-hairy, as are the large deeply 3-lobed leaves, the lobes oval lanceolate and serrate; petioles margined; fruit obovate, 5--6-ribbed and tubercled.--Var. INTEGRIFLIA, Torr. & Gray, is only a smaller form, with the upper leaves, or all of them, undivided, ovate or oval.--Moist river-banks; common.

[*][*] _Leaves many of them alternate, all once or twice pinnatifid._

3. A. artemisiaeflia, L. (ROMAN WORMWOOD. HOG-WEED. BITTER-WEED.) Much branched (1--3 high), hairy or roughish-p.u.b.escent; _leaves thin, twice-pinnatifid_, smoothish above, paler or h.o.a.ry beneath; _fruit_ obovoid or globular, _armed with about 6 short acute teeth or spines_.--Waste places everywhere.--Extremely variable, with finely cut leaves, on the flowering branches often undivided; rarely the spikes bear all fertile heads.

4. A. psilostachya, DC. Paniculate-branched (2--5 high), rough and somewhat h.o.a.ry with short hispid hairs; _leaves once pinnatifid, thickish_, the lobes acute, those of the lower leaves often incised; _fruit_ obovoid, _without tubercles or with very small ones_, p.u.b.escent.--Prairies and plains, Ill., Wisc., Minn., and southwestward.

Perennial, with slender running rootstocks.

44. XaNTHIUM, Tourn. c.o.c.kLEBUR. CLOTBUR.

Sterile and fertile flowers occupying different heads, the latter cl.u.s.tered below, the former in short spikes or racemes above. Sterile involucres and flowers as in Ambrosia, but the scales separate and receptacle cylindrical. Fertile involucre closed, coriaceous, ovoid or oblong, clothed with hooked p.r.i.c.kles so as to form a rough bur, 2-celled, 2-flowered; the flower consisting of a pistil and slender thread-form corolla. Achenes oblong, flat, dest.i.tute of pappus.--Coa.r.s.e and vile weeds, with annual roots, low and branching stout stems, and alternate toothed or lobed petioled leaves; flowering in summer and autumn. (The Greek name of some plant that was used to dye the hair yellow; from ?a????, _yellow_.)

[*] _Leaves attenuate to both ends, with triple spines at the base._

X. SPINSUM, L. (SPINY CLOTBUR.) h.o.a.ry-p.u.b.escent; stems slender, with slender yellow 3-parted spines at the axils; leaves lanceolate or ovate-lanceolate, tapering to a short petiole, white-downy beneath, often 2--3-lobed or cut; fruit ({1/3}' long) pointed with a single short beak.--Waste places on the sea-board and along rivers, Ma.s.s. and southward. (Nat. from Trop. Amer.)