1. D. capillacea, DC. Plant 1--2 high (or even 5--6); leaves dissected into filiform divisions; umbel 5--20-rayed, involucre of filiform bracts usually cleft or parted, and involucels more or less prominent, fruit 1--1" long, ovate, acute.--Wet ground, Ma.s.s. to Fla., west to Ill., Mo., and Tex. June--Oct.

2. D. Nuttallii, DC. Similar in habit; involucral bracts short and entire; fruit very small (" long), as broad as high, blunt.--Ill. (?) to Ark., La., and Tex.

30. CONUM, L. POISON HEMLOCK.

Calyx-teeth obsolete. Fruit ovate, somewhat flattened at the sides, glabrous, with prominent wavy ribs; oil-tubes none, but a layer of secreting cells next the seed, whose face is deeply and narrowly concave.--Poisonous biennial, with spotted stems, large decompound leaves with lanceolate pinnatifid leaflets, involucre and involucels of narrow bracts, and white flowers. (???e???, the Greek name of the Hemlock, by which criminals and philosophers were put to death at Athens.)

C. MACULaTUM, L. A large branching European herb, in waste places, N. Eng. to Penn., and west to Iowa and Minn.

31. CHaeROPHLLUM, L.

Calyx-teeth obsolete. Fruit narrowly oblong to linear, notched at base, with short beak or none, and equal ribs; oil-tubes solitary in the intervals, seed-face more or less deeply grooved.--Moist ground annuals, with ternately decompound leaves, pinnatifid leaflets with oblong obtuse lobes, mostly no involucre, involucels of many bractlets, and white flowers. (Name from ?a???, _to gladden_, and f?????, _a leaf_, alluding to the agreeable odor of the foliage.)

1. C. proc.u.mbens, Crantz. More or less hairy; stems slender, spreading (6--18' high); umbels few-rayed; fruit narrowly oblong (2--3" long), glabrous, contracted but not tapering at the summit, the intervals broader than the ribs.--N. Y. to N. C., west to Mich., Iowa, Ark., and Miss.

Var. Shortii, Torr. & Gray, has more broadly oblong to ovate (often somewhat p.u.b.escent) fruit, not at all contracted at the summit.--Ky. to Ark. and La.

32. OSMORRHZA, Raf. SWEET CICELY.

Calyx-teeth obsolete. Fruit linear to linear-oblong, with prominent caudate attenuation at base, very bristly, with equal ribs; oil-tubes obsolete; seed-face concave.--Glabrous to hirsute perennials (1--3 high) from thick aromatic roots, with ternately compound leaves, ovate variously toothed leaflets, few-leaved involucres and involucels, and white flowers in few-rayed and few-fruited umbels. (Name from ?s?, _a scent_, and ???a, _a root_.)

1. O. brevistylis, DC. Rather stout, _villous-p.u.b.escent_; leaves 2--3-ternate; leaflets 2--3' long, ac.u.minate; fruit (not including the caudate attenuation) 6" long; _stylopodium and style " long_.--From N. Scotia westward through the Northern States, and in the mountains to N. C. May, June.

2. O. longistylis, DC. _Glabrous or slightly p.u.b.escent_; like the last, but with the _style 1" long or more_, and the seed-face more deeply and broadly concave.--N. Scotia to Va., and west to Tenn., E. Kan., and Dak.

33. ERIGeNIA, Nutt. HARBINGER-OF-SPRING.

Calyx-teeth obsolete. Petals obovate or spatulate, flat, entire. Fruit didymous, nearly orbicular and laterally flattened, the carpels incurved at top and bottom, nearly kidney-form, with 5 very slender ribs, and several (1--3) small oil-tubes in the intervals; inner face of the seed hollowed into a broad deep cavity.--A small glabrous vernal plant, producing from a deep round tuber a simple stem, bearing one or two 2--3-ternately divided leaves, and a somewhat imperfect and leafy-bracted compound umbel. Flowers few, white. (Name from ??????e?a, _born in the spring_.)

1. E. bulbsa, Nutt. Stem 3--9' high; leaf-segments linear-oblong; fruit 1" long, 1" broad.--W. New York to Md. and Tenn., and west to Wisc., S. E. Minn., and Kan.

34. HYDROCoTYLE, Tourn. WATER PENNYWORT.

Calyx-teeth obsolete. Fruit strongly flattened laterally, orbicular or shield-shaped; the carpels 5-ribbed, two of the ribs enlarged and often forming a thickened margin; oil-tubes none, but usually a conspicuous oil-bearing layer beneath the epidermis.--Low, mostly smooth, marsh or aquatic perennials, with slender creeping stems, and round shield-shaped or kidney-form leaves, with scale-like stipules. Flowers small, white, in simple umbels or cl.u.s.ters, which are either single or proliferous (one above another), appearing all summer. (Name from ?d??, _water_, and ??t???, _a flat cup_, the peltate leaves of several species being somewhat cup-shaped.)

[*] _Pericarp thin except at the broad corky dorsal and lateral ribs; leaves round-peltate, crenate; peduncles as long as the petioles, from creeping rootstocks._

[+] _Fruit notched at base and apex; intermediate ribs corky._

1. H. umbellata, L. _Umbels many-flowered, simple_ (sometimes proliferous); _pedicels 2--6" long; fruit about 1" broad_, strongly notched, the dorsal ribs prominent but obtuse.--Ma.s.s. to Minn., south to the Gulf.

2. H. Canbyi, Coult. & Rose. _Umbels 3--9-flowered, generally proliferous; pedicels very short_, but distinct; _fruit about 2 lines broad_; carpels broader and more flattened than in the preceding, sharper margined, the dorsal and lateral ribs much more prominent; seed-section much narrower. (H. umbellata, var.? ambigua, _Gray_, Manual).--N. J. to Md.

[+][+] _Fruit not notched; intermediate ribs not corky._

3. H. verticillata, Thunb. Umbels few-flowered, proliferous, forming an interrupted spike; pedicels very short or none; fruit 1--2" broad; dorsal and lateral ribs very prominent. (H. interrupta, _Muhl._)--Ma.s.s.

to Fla.

[*][*] _Pericarp uniformly corky-thickened and ribs all filiform; leaves not peltate; peduncles much shorter than the petioles._

[+] _Fruit small, without secondary ribs or reticulations; involucre small or none._

4. H. Americana, L. Stems filiform, _branching and creeping; leaves thin_, round-reniform, _crenate-lobed_ and the lobes crenate, shining; few-flowered umbels _axillary and almost sessile_; fruit less than 1"

broad; intermediate ribs prominent; no oil-bearing layer; seed-section broadly oval.--Common. (Addendum) Propagating by filiform tuberiferous stolons.

5. H. ranunculodes, L. f. _Usually floating; leaves thicker_, round-reniform, 3--7-cleft, the lobes crenate; _peduncles 1--3' long, reflexed in fruit_; capitate umbel 5--10-flowered; fruit 1--1" broad; ribs rather obscure; seed-section oblong.--E. Penn. to Fla., thence westward.

[+][+] _Fruit larger (2--2" broad), with prominent secondary ribs and reticulations; the 2--4-flowered umbel subtended by two conspicuous bracts._

6. H. Asiatica, L. Petioles and peduncles (1--2' long) cl.u.s.tered on creeping stems or runners; leaves ovate-cordate, repand-toothed, thickish; seed-section narrowly oblong. (H. repanda, _Pers._)--Md. to Fla. and Tex. (Widely distributed in the tropics and southern hemisphere.)

35. ERNGIUM, Tourn. ERYNGO.

Calyx-teeth prominent, rigid and persistent. Styles slender. Fruit ovate or obovate, covered with little hyaline scales or tubercles, with no ribs, and usually 5 slender oil-tubes on each carpel.--Chiefly perennials, with coriaceous, toothed, cut, or p.r.i.c.kly leaves, and blue or white bracted flowers closely sessile in dense heads. (A name used by Dioscorides, of uncertain origin.)

[*] _Stout, with parallel-veined elongated linear thick leaves._

1. E. yuccaeflium, Michx. (RATTLESNAKE-MASTER. b.u.t.tON SNAKE-ROOT.) Branching above, 1--6 high; leaves rigid, tapering to a point (lower sometimes 2--3 long), the margins remotely bristly; heads ovate-globose (9" long), with ovate-lanceolate mostly entire cuspidate-tipped bracts shorter than the head, and similar bractlets.--Dry or damp soil, N. J.

to Minn., south to Fla. and Tex. July--Sept.

[*][*] _Tall and often stout; leaves thick, not parallel-veined._

2. E. Virginianum, Lam. _Slender_ (1--3 high); _radical and lower stem-leaves linear- to oblong-lanceolate, on long_ (sometimes 1 long) _fistulous petioles_, entire or with small hooked teeth; upper leaves sessile, spiny-toothed or laciniate; heads ovate-oblong (6" long), with spiny-toothed or entire reflexed bracts, and _bractlets with 3 spiny cusps_ (the middle one largest).--Margins of ponds and streams, N. J. to Fla. and Tex., near the coast. Aug., Sept.

3. E. Leavenworthii, Torr. & Gray. Stout (1--3 high); lowest stem-leaves broadly oblanceolate, spinosely toothed, the rest sessile and _deeply palmately-parted into narrow incisely-pinnatifid spreading pungent segments_; heads ovate-oblong (1--1' long), with pinnatifid spinose bracts and 3--7-cuspidate bractlets, the terminal ones very prominent and resembling the bracts.--Dry soil, E. Kan., Ark., and Tex.

[*][*][*] _Prostrate and slender, rooting at the joints, diffusely branched, with small thin unarmed leaves and very small heads._

4. E. prostratum, Nutt. Lower leaves oblong, entire, few-toothed, or lobed at base; upper leaves smaller, cl.u.s.tered at the rooting joints, ovate, few-toothed or entire (occasionally some additional trifid ones); reflexed bracts longer than the oblong heads (2--4" long).--Wet places, S. Mo. to Fla. and Tex.

36. SANiCULA, Tourn. SANICLE. BLACK SNAKEROOT.

Calyx-teeth manifest, persistent. Fruit globular; the carpels not separating spontaneously, ribless, thickly clothed with hooked p.r.i.c.kles, each with 5 oil-tubes.--Perennial rather tall glabrous herbs, with few palmately-lobed or parted leaves, those from the root long-petioled.

Umbels irregular or compound, the flowers (greenish or yellowish) capitate in the umbellets, perfect, and with staminate ones intermixed.

Involucre and involucels few-leaved. (Name said to be from _sano_, to heal; or perhaps from _San Nicolas_.)

1. S. Marylandica, L. Stem 1--3 high; leaves 3--7-parted, the divisions mostly sharply cut and serrate; sterile flowers numerous and long-pedicelled; fruit 1--2" long, the styles longer than the p.r.i.c.kles.--Throughout our range, south to Ga. and Tenn., west to E. Kan.

and Minn. May--Aug.

Var. Canadensis, Torr., has comparatively few and short-pedicelled sterile flowers, and styles shorter than the p.r.i.c.kles. (S. Canadensis, _L._)--With the last, but westward only to Minn. and E. Kan.