to provide for germination and for sufficient growth of stem to enable the plant to reach some other plant into which it immediately sends its suckers and thus becomes established upon its host from which it afterwards obtains its nourishment. Dodders contain no green coloring matter, or chlorophyll as it is called, so are unable to assimilate raw material and make starch of it as greenleaved plants do, hence are dependent upon other plants for nourishment that has already been

converted. Such plants are called parasites. Dodder seeds retain their vitality five years or more, hence must be considered as especially pernicious when present in commercial seeds.

Clover Dodder (Cuscuta Epithymum, Murr.). Slender, reddish stems; capitate flowers with pink calyx, corolla with four to five erect lobes; scales large, incurved; stemless, exserted, filiform stamens; capsule circumsessile with withering corolla. Found in both clover and alfalfa; native to Europe, but now found in the United States from New England to Iowa and South Dakota, the Rocky Mountains and the Pacific coast. The large seeded Chilean dodder (C. racemosa, var. chiliana) is found in clover seed sent from Chili. Field Dodder (Cuscuta arvensis, Beyrich).-Pale yellow, filiform stems; flowers in small, nearly sessile clusters; calyx of five obtuse lobes; corolla nearly campanulate, five-lobed, longer than the tube, tips reflexed; scales large, ovate; stamens not exserted; style shorter than the ovary; stigmas capitate; capsule globose, indehiscent. A parasite on shrubs and various herbs as well as on clover and alfalfa from New England to Florida, Canada to the

Fig. 136a. Clover dodder on alfalfa. (Dewey.)

Rocky Mountains, California and Mexico. C. decora, found in the southern states, has coarse stems, panicled, papillose flowers, triangular calyx lobes, pointed capsule and is seen on alfalfa. Flax dodder (C. epilinum) has slender, reddish stems, flowers in loose clusters, linear filiform stigmas and occurs rather sparingly on flax in the northern states.

Phlox Family (Polemoniaceae.)-Herbs with alternate, opposite leaves; flowers perfect, regular, clustered; calyx bellshaped, five-cleft; corolla gamopetalous, the limb five-parted; stamens five, inserted on the tube of the corolla and alternate with the lobes; pistil with a three-celled ovary and a three-lobed style; ovules two to many; fruit a capsule, three-celled, three-valved; seed-coat sometimes mucilaginous, producing spiricles; embryo straight; cotyledons flat. About 200 species of wide distribution.

(Navarretia

Skunkweed, Pepperweed squarrosa, H. and A.).-A rigid, rather stout annual, becoming much branched; very glandular, viscid, fetid; leaves twice pinnatifid or pinnately parted and the Fig.136b. Field divisions either parted or incised, upper dodder (Cuscuta arvensis) on red leaves and bracts spinescent; flowers clover. (Dewey densely clustered; corolla blue, rarely Hayden.) whitish, funnel form or almost salver form, rather shorter than the usually entire calyx lobes; calyx lobe often laciniate or spinulose-tipped; stamens unequal in length, slender, tubular. Open ground, common throughout western California and in the foothills extending into Oregon..

Waterleaf Family (Hydrophyllaceae.)—Mostly hirsute herbs with alternate or rarely opposite leaves; flowers

perfect, regular, five-parted in spikes, racemes, cymes or solitary; stamens five, inserted on the corolla; style twocleft or two separate styles; ovary one to two-celled, when one-celled with two parietal placentæ; fruit a twocelled capsule; seeds mostly reticulated. A small order of about 160 species.

Waterleaf (Ellisia nyctelia, L.).—A minutely or sparingly roughish, pubescent, branched annual from six to fourteen inches high; leaves pinnately parted into seven to twelve lanceolate, or linear-oblong, cut-toothed divisions; peduncles one-flowered, calyx lobes lanceolate, pointed; corolla whitish; stamens included; capsule globose. In grain fields and moist places from the Central States to Dakota and Northwest Territory to Kansas.

Borage Family (Boraginaceae.)-Herbs, shrubs or trees, with alternate, entire, rough, or frequently scabrous or setose leaves; flowers perfect, usually regular, generally blue, borne in one-sided spikes, racemes, cymes or scattered; calyx inferior, mostly five-lobed or five-cleft; corolla short, bell or wheel-shaped, five-cleft or five. parted; stamens as many as the lobes of the corolla and alternate with them; ovary superior, deeply two-lobed, style entire; capsule globular; fruit usually forming four seedlike, one-seeded nutlets, but sometimes separating into two, two-seeded nutlets.

European Heliotrope (Heliotropium europaeum, L.).— An erect annual, branched, roughish, pubescent; leaves oval; petiole long, narrow at the base; flowers borne in one-sided bractless spikes, the terminal spikes in pairs; calyx spreading, the segments shorter than the corolla tube; anthers, distinct, obtuse. Common in waste places, southward, and from New York to Pennsylvania and Florida.

Stickseed (Lappula echinata, Gilbert).-An erect annual from one to two feet high; pale, leafy, hispid with erect branches; leaves linear or linear-oblong; racemes

one-sided, bracteolate; calyx segments lanceolate; corolla blue; nutlets rough granulate or tuberculate on the back, the margins with a double row of slender prickles. Abundant in waste places along roadsides from eastern Canada and New England to Minnesota, Kansas and British Columbia. Weedy also in Europe, where it is a native. Western Stickseed Stickseed (Lappula floribunda, (Lehm.) Greene). A biennial or perennial from one to two feet high; leaves oblong to linear-lanceolate, pubescent; flowers in erect racemes, pale blue; nutlets keeled and with a row of subulate prickles. Common in the Rocky Mountains. Beggar's lice (L. virginiana, (L.) Greene) has stems two to four feet high, with ovate-oblong or oval stem leaves, petioled; pedicels short, deflexed in fruit; nutlets curved by flattened barbed prickles. Common in the North.

Yellow Burweed, Fireweed or Yellow Tarweed (Amsinckia intermedia, F. and M.).-A hispid, erect annual, one to two feet high, with oblong, ovate to linear leaves, lower sometimes lanceolate; yellow flowers in a loose spike or raceme; the bristles of the calyx whitish or merely yellowish; corolla tube slightly longer than the narrow, linear calyx lobes; anthers oblong; nutlets not half the length of the calyx lobes. In dry open grounds in eastern California.

Corn Gromwell, Puccoon (Lithospermum arvense, L.). -A small annual or winter annual with erect stems six to twelve inches high, somewhat rough with minute hairs; leaves lanceolate or linear; corolla funnel-form, regular, white, five-lobed; calyx five-parted; stamens inserted on the tube of the corolla; style one; fruit fourseeded, like one-seeded nutlets. Found on sandy banks and roadsides. Naturalized from Europe. The perennial hoary puccoon (L. canescens), softly pubescent, with sessile, oblong, linear or linear-oblong leaves, yellow flowers and white nutlets, is common from New England,

and the Mississippi Valley to Arizona. The rough puccoon (L. hirtum) is hispid with bristly hairs; leaves of the stem lanceolate or linear, of the flowering branches ovateoblong, bristly ciliate; flowers peduncled, crowded, showy yellow. In sandy soils, especially pine barrens from New York to Minnesota and Nebraska.

Blueweed (Echium vulgare, L.).-An erect, rough, bristly biennial, eighteen inches to two feet high, with an erect, mostly simple stem; leaves of the stem linearlanceolate, sessile; flowers in cymose clusters; corolla reddish purple, changing to blue; tube funnel-form, border unequal, spreading, five-lobed; stamens five, inserted on the tube; style threadlike; nutlets roughened or wrinkled. A common weed along roadsides, fields, and meadows from New England to Indiana.

Verbena Family (Verbenaceae).-Herbs, shrubs or trees with opposite or alternate leaves; perfect, regular or somewhat irregular flowers borne in spikes, racemes or panicles; calyx generally persistent, inferior, four to five-lobed or cleft; corolla four to five-cleft, tube cylindrical; stamens four, didynamous, or two; ovary superior, two to four-celled or more; fruit dry or drupaceous, splitting into one to four nutlets. A large order, found chiefly in tropical regions, and contains about 1,200 species.

Hoary Vervain (Verbena stricta, Vent.).—A downy, simple or branched perennial from one to three feet high; leaves sessile, obovate or oblong, serrate, covered with soft hairs; flowers in long hairy spikes, large, purple; calyx tubular, salver-form; fruit splitting into four seedlike nutlets. Common in sandy soil, knolls and especially upland pastures in the West. The blue vervain (V. hastata), a perennial from four to six feet high with lanceolate or oblong-lanceolate, taper-pointed leaves; blue flowers in linear spikes, is common in low grounds. The narrow-leaved verbena (V. angustifolia) is a simple or somewhat branched perennial; leaves narrowly lanceo