1. A. mercurialna, Muell. Stem erect, nearly simple (1--2 high), sericeous; leaves sessile, oblong-ovate to lanceolate, entire, p.u.b.escent with appressed hairs or glabrate, somewhat rigid; raceme many-flowered, exceeding the leaves; ovary sericeous; capsule appressed-p.u.b.escent.--Kan. to Ark. and Tex.

8. ACAL?PHA, L. THREE-SEEDED MERCURY.

Flowers moncious; the sterile very small, cl.u.s.tered in spikes, with the few or solitary fertile flowers at their base, or sometimes in separate spikes. Calyx of the sterile flowers 4-parted and valvate in bud; of the fertile, 3--5-parted. Corolla none. Stamens 8--16; filaments short, monadelphous at base; anther-cells separate, long, often worm-shaped, hanging from the apex of the filament. Styles 3, the upper face or stigmas cut-fringed (usually red). Capsule separating into 3 globular 2-valved carpels, rarely of only one carpel.--Herbs (ours annuals), or in the tropics often shrubs, resembling Nettles or Amaranths; the leaves alternate, petioled, with stipules. Cl.u.s.ters of sterile flowers with a minute bract; the fertile surrounded by a large and leaf-like cut-lobed persistent bract. (??a??f?, an ancient name of the Nettle.)

[*] _Fruit smooth or merely p.u.b.escent; seeds nearly smooth._

1. A. Virginica, L. Smoothish or hairy (1--2 high), often turning purple; leaves ovate or oblong-ovate, obtusely and spa.r.s.ely serrate, long-petioled; sterile spike rather few-flowered, mostly shorter than the large leaf like palmately 5--9-cleft fruiting bracts; fertile flowers 1--3 in each axil.--Fields and open places, N. Eng. to Ont. and Minn., south to the Gulf. July--Sept.

Var. gracilens, Muell. Leaves lanceolate or even linear, less toothed and shorter-petioled; the slender sterile spike often 1' long, and much surpa.s.sing the less cleft or few-toothed fruiting bracts.--Sandy dry soil, R. I. and Conn. to Fla., west to Ill., E. Kan. and Tex.

[*][*] _Fruit echinate with soft bristly green projections; seeds rough-wrinkled._

2. A. Caroliniana, Ell. Leaves thin, ovate-cordate, sharply and closely serrate-toothed, abruptly ac.u.minate, long-petioled; sterile spikes short, axillary; the fertile ones mostly terminal and elongated, their bracts deeply cut into many linear lobes.--N. J. to Fla., west to Ohio, Kan., and Tex.

9. RiCINUS, Linn. CASTOR-OIL PLANT.

Flowers in racemose or panicled cl.u.s.ters, the fertile above, the staminate below. Calyx 5-parted. Stamens very numerous, with repeatedly branching filaments. Styles 3, united at base, each bifid, red. Capsule large, 3-lobed, with 3 large seeds.--A tall stately annual, with very large alternate peltate and palmately 7--11-cleft leaves (often 1--2 broad). (The ancient Roman name of the plant.)

R. COMMuNIS, L.--Cultivated extensively for ornament, and sparingly escaped in Md., Mo., and southward. Very variable.

10. TRaGIA, Plumier.

Flowers moncious, in racemes, apetalous. _Ster. Fl._ Calyx 3--5- (chiefly 3-) parted, valvate in the bud. Stamens 2 or 3; filaments short; anther-cells united. _Fert. Fl._ Calyx 3--8-parted, persistent.

Style 3-cleft or 3-parted; the branches 3, simple. Capsule 3-celled, 3-lobed, bristly, separating into three 2-valved 1-seeded carpels. Seeds not carunculate.--Erect or climbing plants (perennial herbs in U. S.), p.u.b.escent or hispid, sometimes stinging, with mostly alternate stipulate leaves; the small flowered racemes terminal or opposite the leaves; the sterile flowers above, the few fertile at the base all with small bracts. (Named for the early herbalist _Bock_, latinized _Tragus_.)

1. T. innocua, Walt. _Erect_, paniculate-branched, _softly hairy-p.u.b.escent_ (6--12' high); _leaves_ varying from obovate-oblong to narrowly linear, _acute at base_, obtusely or sinuately few-toothed or lobed, sometimes entire, _short-petioled or sessile_, paler beneath; sterile calyx usually 4-parted; stamens 2. (T. urens, _L._)--Dry sandy soil, E. Va. to Fla. and La. May--Aug.--Not stinging.

2. T. nepetaeflia, Cav. _Erect or reclining_ or slightly twining, hirsute with stinging hairs; _leaves ovate-lanceolate or triangular-lanceolate_, or the lower ovate, _all somewhat cordate or truncate at base_, coa.r.s.ely cut-toothed, _short-petioled_; sterile calyx usually 3-parted and stamens 3. (T. urticaefolia, _Michx._)--Virginia (_Pursh_), and common southward to Fla. and Tex., Mo., Kan., and westward.--T. STYLaRIS, Muell., of the southwest, which is reported from Kan., may be distinguished by its 4--5-parted sterile calyx, 4--5 stamens, and elongated styles.

3. T. macrocarpa, Willd. _Twining_, somewhat hirsute; _leaves deeply cordate_, ovate, mostly narrowly ac.u.minate, sharply serrate (3--5'

long), all but the uppermost _long-petioled_; pod ' broad. (T.

cordata, _Michx._)--Ky. to Ga., Fla., and La.

11. STILLiNGIA, Garden.

Flowers moncious, aggregated in a terminal spike. Petals and glands of the disk none. Calyx 2--3-cleft or parted; the divisions imbricated in the bud. Stamens 2 or 3; anthers adnate, turned outward. Style thick; stigmas 3, diverging, simple. Capsule 3-celled, 3-lobed, 3-seeded. Seed carunculate.--Smooth upright plants with the alternate leaves mostly 2-glandular at base; the fertile flowers few at the base of the dense sterile spike (rarely separate); the bract for each cl.u.s.ter with a large gland on each side. (Named for _Dr. B. Stillingfleet_.)

1. S. sylvatica, L. Herbaceous (1--3 high); leaves almost sessile, oblong-lanceolate, serrulate; glands of the spike saucer-shaped.--Sandy and dry soil, Va. to Fla., west to Kan. and Tex. June--Sept.

ORDER 99. URTICaCEae. (NETTLE FAMILY.)

_Plants with stipules, and moncious or dicious or rarely (in the_ Elm Family) _perfect flowers, furnished with a regular calyx, free from the 1-celled (rarely 2-celled) ovary which forms a 1-seeded fruit; the embryo in the alb.u.men when there is any, its radicle pointing upward; stamens as many as the lobes of the calyx and opposite them, or sometimes fewer._ Cotyledons usually broad. Stipules often deciduous.--A large order (far the greater part tropical).

Tribe I. ULMEae. Flowers mostly polygamous, upon the last year's branches. Anthers erect in the bud, extrorse. Styles or stigmas 2. Fruit a winged samara or nut-like. Seed suspended. Embryo straight.--Trees, with alternate serrate pinnately veined leaves and fugacious stipules.

1. Ulmus. Flowers preceding the leaves. Ovary 1--2-ovuled. Fruit winged all around.

2. Planera. Flowers appearing with the leaves. Ovule one. Fruit wingless, nut-like.

Tribe II. CELTIDEae. As in Tribe I., but the dicious-polygamous flowers upon branches of the same year; anthers introrse; fruit a drupe; embryo curved.

3. Celtis. Ovary 1-ovuled. Flowers appearing with the leaves. Leaves 3-nerved at base.

Tribe III. CANNABINEae. Flowers dicious; the sterile racemed or panicled; the fertile in cl.u.s.ters or catkins, the calyx of one sepal embracing the ovary. Filaments short, erect in the bud. Stigmas 2, elongated. Ovary 1-celled, with a pendulous ovule, forming a small glandular achene in fruit. Embryo curved or coiled.--Erect or climbing herbs, with watery juice, mostly opposite lobed or divided leaves, persistent stipules, and a fibrous inner bark.

4. Cannabis. Fertile flowers spiked-cl.u.s.tered. Leaves 5--7-divided.

Erect.

5. Humulus. Fertile flowers in a short spike forming a membranaceous catkin in fruit. Leaves 3--5-lobed. Climbing.

Tribe IV. MOREae. Flowers unis.e.xual, racemose, spicate or capitate; calyx becoming fleshy or juicy in fruit. Anthers inflexed in the bud. Style undivided or 2-parted, filiform; ovule pendulous; fruit an achene, embryo curved.--Trees or shrubs, with milky juice, alternate leaves, and fugacious stipules.

6. Maclura. Sterile flowers in loose racemes; fertile in globose heads.

Leaves entire.

7. Morus. Fertile and sterile flowers in separate spikes. Leaves dentate, 3-nerved.

Tribe V. URTICEae. Flowers unis.e.xual. Filaments indexed in the bud. Style or stigma simple. Ovary 1-celled, with an erect ovule, forming an achene in fruit. Embryo straight.--Herbs with watery juice, tough fibrous bark, and opposite or alternate leaves; often armed with stinging hairs.

[*] Calyx in the fertile flowers of 2--5 separate or nearly separate sepals.

[+] Plant beset with stinging bristles.

8. Urtica. Sepals 4 in both fertile and sterile flowers. Achene straight and erect, enclosed by the 2 inner and larger sepals. Stigma capitate tufted. Leaves opposite.

9. Laportea. Sepals 5 in the sterile flowers, 4 in the fertile, or apparently only 2. Stigma long-subulate. Achene very oblique, deflexed, nearly naked. Leaves alternate.

[+][+] Plant wholly dest.i.tute of stinging bristles. Leaves alternate.

10. Pilea. Sepals 3 or 4, those of the fertile flowers unequal, all or all but one small. Achene partly naked, straight and erect. Stigma pencil-tufted. Smooth and shining.

[*][*] Fertile calyx tubular or cup-shaped, enclosing the achene.

Unarmed.

11. Bhmeria. Flower-cl.u.s.ters spiked, not involucrate. Style long and thread-shaped, stigmatic down one side. Leaves opposite, serrate.

12. Parietaria. Flowers in involucrate-bracted cl.u.s.ters. Stigma tufted.

Leaves alternate, entire.

1. uLMUS, L. ELM.

Calyx bell-shaped, 4--9-cleft. Stamens 4--9, with long and slender filaments. Ovary 1--2-celled, with a single anatropous ovule suspended from the summit of each cell; styles 2, short, diverging, stigmatic along the inner edge. Fruit a 1-celled and 1-seeded membranaceous samara, winged all around. Alb.u.men none; embryo straight; the cotyledons large.--Flowers polygamous, purplish or yellowish, in lateral cl.u.s.ters, in our species preceding the leaves, which are strongly straight-veined, short-petioled, and oblique or unequally somewhat heart-shaped at base. Stipules small, caducous. (The cla.s.sical Latin name.)