Part 13

Seneca snakeroot, known also as senega or seneca root (Polygala senega, fig. 8), is a small native perennial, occurring in rocky woods in the eastern United States and Canada. Seneca is not yet grown on a commercial scale, although cultivated experimentally in a number of places. The root is used in medicine.

Seneca can be grown in good garden soil or in rather firm, stony soil, provided it contains a fair proportion of leaf mold or very well rotted manure. Shade is not essential, although the plant thrives in partial shade or under modified forest conditions. Roots for propagation may be obtained from dealers or may be collected from the wild in autumn or early spring. If set 15 inches apart in rows, the plants may be readily cultivated until they reach a marketable size. The seeds ripen in June and may then be planted, or they may be stratified by mixing with sand and buried in boxes or flower pots in moist soil until the following spring, when they may be sown in seed beds or shallow boxes of loam and leaf mold. The seedlings when old enough to be handled safely may be transplanted to the permanent beds and set in rows to facilitate cultivation. In cold situations they will probably need to be protected during the first winter after transplanting. A light covering of straw or pine needles will be sufficient to protect them from severe frost.

The plant is slow in growth, but experiments thus far indicate that about four years are required to obtain marketable roots. The roots should be dug in the fall, thoroughly cleaned, and dried. There are no reliable data on the probable yield. Seneca root is in constant demand, and collectors formerly received from 35 to 50 cents a pound. The price to collectors in June, 1920, was 90 cents a pound.

SERPENTARIA.

Serpentaria, or Virginia snakeroot (Aristolochia serpentaria), is a native perennial plant occurring in rich woods in the eastern part of the United States, and most abundantly along the Allegheny Mountains. The roots of this plant are used in medicine.

Like many other woodland plants, serpentaria requires a rich, moist loam and partial shade for its best development. It may be readily propagated from seeds, which, however, require several months for germination. The seeds are best sown in a well-prepared seed bed as soon as they are ripe. They may also be sown broadcast or in drills 6 inches apart and lightly covered with leaf mold. A thin mulch of straw or leaves will afford the necessary winter protection. In the spring the plants may be set 6 inches apart each way in the permanent beds. Plantings have been made in the open, in which case the plants were set 4 inches apart in rows 16 inches apart, but the results have been less satisfactory than with plantings made under shade.

The roots are collected in the fall, thoroughly cleaned, and carefully dried. Satisfactory data on probable yields under cultivation are not available. The price usually ranges from 30 to 45 cents a pound.

SPEARMINT.

Spearmint (Mentha spicata) is a well-known perennial of the mint family which is very frequently found growing wild in moist situations throughout the eastern half of the United States. It is widely used for seasoning meats, and the leaves and flowering tops, as well as the volatile oil distilled from the whole herb, form marketable drug products.

Spearmint is easily grown in any fertile soil which is fairly moist. Its culture and the method of distilling the volatile oil are the same as for peppermint. To prepare the dry herb for market the leaves and flowering tops are collected when the first flowers appear and before the leaves begin to fall and are carefully dried in the shade. The demand for the dry herb is small, but the annual market requirement for the oil is about 50,000 pounds.

On ordinary soils the yield of oil varies from 10 to 20 pounds per acre, according to stand and season, but on muck lands the yield is usually only a little less than that of peppermint. Before the war the wholesale prices for the oil ranged from $1.50 to $5, averaging about $3.30 a pound. The price in June, 1920, was $12 a pound. The dry herb, which formerly brought from 3 to 4 cents, is now quoted at 6 to 12 cents a pound.

For further information on the growing of spearmint, see Farmers' Bulletin 694, entitled "The Cultivation of Peppermint and Spearmint."

STRAMONIUM.

Stramonium, Jamestown weed, or jimson weed (Datura stramonium), is a poisonous annual of the nightshade family, which occurs as a common weed in almost all parts of this country except the West and North. The leaves and seeds are used medicinally.

Although stramonium grows wild on a variety of soils, it thrives best under cultivation in rich and rather heavy soils which are fairly well supplied with lime. It grows readily from seed, which may be sown in the open early in the spring in drills 3 feet apart and barely covered. When the plants are well established they are thinned to stand 12 to 15 inches apart in the row. The plants can be readily transplanted, and gaps occurring in the rows may be filled in with the plants removed in thinning. Cultivation sufficient to keep the soil free from weeds is necessary for good growth.

Cultivated plants are frequently attacked by leaf-eating insects, especially in the early stages of growth, and it is often necessary to use lime or other insect repellents to prevent the destruction of the crop.

The leaves, which are collected when the plant is in full bloom, may be picked in the field, but time will be saved if the entire plant is cut and dried in an artificially heated curing room at a temperature of 100° to 110° F. When the leaves are dry they can be readily stripped from the stems, and should be baled for shipment. Such seed as is ripe may be easily thrashed out of the capsules after the leaves have been removed from the stems.

Yields of dry leaf at the rate of 1,000 to 1,500 pounds per acre have been obtained. The yield of seed is much more variable, and is estimated to range from 500 to 2,000 pounds per acre. The prewar price for the leaves varied from 2 to 10 cents and for the seed from 3 to 7 cents a pound. The price in June, 1920, for the leaves was 22 cents and for the seed 12 cents a pound.

TANSY.

Tansy (Tanacetum vulgare) is a European perennial plant, long cultivated in this country in gardens, from which it has escaped, and it now occurs as a weed along fence rows and roadsides. The leaves and flowering tops are in some demand for medicinal purposes. The herb also yields a volatile oil, for which there is a small market.

Tansy grows well on almost any good soil, but rich and rather heavy soils well supplied with moisture favor a heavy growth of herb. It may be propagated from seed, but is more readily propagated by division of the roots early in spring. The divisions are set 18 inches apart in rows 3 feet apart. Seed may be sown very early in the spring in the open or in seed beds, and the seedlings later transplanted to the field. Such cultivation as is usually given to garden crops will be sufficient.

The plants are cut late in the summer when in full flower, the leaves and tops being separated from the stems and dried without exposure to the sun, as the trade desires a bright-green color. For the volatile oil the plants are allowed to lie in the field after cutting until they have lost a considerable portion of their moisture. They are then brought to the still and the oil removed by the usual method of steam distillation.

A yield of about 2,000 pounds of dry leaves and flowering tops per acre may be obtained under good conditions. The yield of oil varies, but about 20 pounds per acre is a fair average. In the United States the center of production of oil of tansy is Michigan, where about 2,500 pounds are distilled annually. The price of the oil in June, 1920, was about $8 a pound. The price of the leaves and tops usually ranges from 3 to 5 cents a pound.

THYME.

Thyme (Thymus vulgaris) is a shrublike perennial plant of the mint family, native to southwestern Europe. It is a common garden plant, which lives for many years under good culture. The herb, often used for seasoning and flavoring, yields the oil of thyme, which has well-recognized medicinal properties.

Thyme grows well from seed, which may be sown early in the spring in drills 3 feet apart, or the plants may be started in a greenhouse or in seed beds outside and later set at intervals of about 18 inches in rows 2 to 3 feet apart. Thyme may also be propagated, like geraniums, from cuttings rooted in sand under glass. The plants grow well in mellow upland soil of good quality, and should be well cultivated and kept free from weeds throughout the growing season.

For preparing the dry herb only the flowering tops are used, and these are cut when the plant is in full bloom and carefully dried in the shade in order to preserve the natural color. The volatile oil is obtained from the entire herb, which is preferably cut when in full flower and subjected to steam distillation without previous drying.

Returns from experimental areas have shown great variations in the yield, which has averaged about a ton of green herb per acre. Normally the yield from a planting increases for several years, as the plants become better established, and yields at the rate of about a ton of dry herb per acre have been reported. The wholesale price in June, 1920, for the dry herb ranged from 11 to 15 cents a pound; for the imported oil, from $1.85 to $2.25 a pound, according to quality.