Corn Silk

Corn Silk

This genus of four species of usually annual grasses is native to C America. Zea mays (corn) has been cultivated for over 5500 years - possibly as long as 7000 years - in the Americas, from Chile to Canada. Following the Spanish conquest of Mexico and Peru in the 16th century, corn was taken to Africa, and spread worldwide. It tolerates a range of climates and is now a major crop in many parts of the world. Corn makes exotic feature plants; varieties with variegated leaves and multi-colored ears have been grown in containers and borders since at least the the 19th century. The culinary uses of corn are well known. There are five principle kinds: dent corn (mostly white to yellow grains); flint corn (which shrinks on drying, and may have white, yellow, red, purple, or blue-black grains, often striped or mottled); popcorn (a primative strain with hard grains, specifically grown for popcorn); sweet corn (with a higher sugar content and best as a vegetable); and waxy corn (containing starch with a waxy appearance). Dent and flint corn are widely grown for oil, cereals, flour, and animal fodder. Waxy corn yields a tapioca-like starch, used mainly in the Far East. Less familiar is the role of corn as a medicinal herb. The female flowers (cornsilk) were once used in spells and divination; they contain allantoin (as found in Symphytum officinale, See, Comfrey), alkaloids, and large amounts of potassium that compensate for the loss of urine due to the herb's diuretic effect. Aztec herbals mention the plant, which was apparently used to clear heat from the heart. It was also used in Mayan and Incan medicine. Zea mays reached China from N America after Li Shi Zhen's time (1518-93) and was first mentioned as an herb in the Sichuan Journal of Chinese Herbal Medicine in the 20th century. Its most recent use is in the form of a gel, extracted from corn bran, which is used as a medical dressing for leg ulcers, pressure sores, and other slow-healing skin conditions.

Corn silk, the long, silky, yellow threads that grow between the leaves and ears of corn, gets ist scientific name from the Greek word zea, which means "to live", and the Spanish word maiz, the name used for corn in Haiti, where corn is beleived to have originated. The corn silk threads, which are the female portion of the corn plant, are gathered once the plant sheds its pollen and used in the form or tea or powder to treat urinary problems.

Robust, upright annual with arching, pointed, lanceolate leaves, 30cm-1.5m (1-5ft) long. Male and female flowers are borne separately on the same plant in early summer; males in a tassel to 40cm (16in) long at the top of the stem; females in a cluster in the leaf axils, terminating in long filaments (cornsilk) and enclosed by overlapping leaf-like sheaths that form a husk. Female flowers are followed by an ear, about 20cm (8in) long, consisting of close-set rows of angular seeds, about 5mm (¼n) long.

Common Name:

Corn Silk

Other Names:

Corn, Indian Corn, Maize, Maize Silk, Stigmata Maydis

Botanical Name:

Zea mays

Genus:

Zea

Family:

Poaceae

Native Location:

Mexico

Cultivation:

Rich, well-drained soil in sun. Zea mays is wind-pollinated and fruits better if grown in a block. Birds may damage the ears.

Propagation:

By seed sown in spring at 18°C (64°F)

Harvest:

Cornsilk is collected in summer before the strands wither and is dried for use in decoctions, infusions, liquid extracts, and syrup. Ears are cut when immature for use as a vegetable, and when ripe for processing as cereals, flour, oil, and syrup.

Height:

2-3m (6-10ft)

Width:

45-60cm (18-24in)

Variations:

Black Aztec
Produces white, unripe seeds that turn blue-black when ripe. A pre-Columbian cultivar, reportedly grown for 2000 years.

Strawberry Corn
Bears rounded ears, 5cm (2in) long, of mahogany-red seeds, enclosed in yellow-green husks. Suitable for popping.
Height: 1-1.2m (3-4ft)
Width: 45cm (18in)

Variegata
Has yellow-seeded ears and creamy-white striped foliage.
Height: 90cm (36in)
Width: 30-45cm (12-18in)

Hardiness:

Half Hardy

Parts Used:

Stigmas and styles of female flowers (cornsilk, yu mi xu), fruits (ears), seeds, oil.

Properties:

A sweet, cooling, soothing herb that is diuretic, lowers blood sugar levels, stimulates bile flow, and prevents formation of urinary stones.

Medicinal Uses:

Internally for cystitis, urinary stones, urethritis, prostatitis, and enuresis in children. Combines well with Elymus repens (See, Quack Grass) and Arctostaphylos uva-ursi (See, Bearberry) or Agathoshma species (See, Oval-leaf Buchu) for cystitis; with Agrimonia eupatoria (See, Agrimony) and Equisetum arvense (See, Field Horsetail) for enuresis; and with Aphanes arvensis (See, Parsley Piert) and Eupatorium purpureum (See, Hemp Agrimony) for urinary stones. Used similarly in Chinese medicine for urinary problems, also for gallstones, jaundice, hepatitis, and cirrhosis. Externally, in the form of a poultice made from cornmeal, for sores or boils.
To treat disorders of the liver and urinary tract.

Typical Dose:

A typical daily dose of corn silk may range from 4 to 8 gm of dried stigma.

Possible Side Effects:

Corn silk's side effects include lowered levels of potassium in the blood.

Drug Interactions:

Taking corn silk with these drugs may increase the risk of hypokalemia (low levels of potassium in the blood):
Acetazolamide, (Apo-Acetazolamide, Diamox Sequels)	Azosemide, (Diat)	Bumetanide, (Bumex, Burinex)	Chlorothiazide, (Diuril)
Chlorthalidone, (Apo-Chlorthalidone, Thalitone)	Ethacrynic Acid, (Edecrin)	Etozolin, (Elkapin)	Furosemide, (Apo-Furosemide, Lasix)
Hydrochlorothiazide, (Apo-Hydro, Microzide)	Hydroflumethiazide, (Diucardin, Saluron)	Indapamide, (Lozol, Nu-Indapamide)	Mannitol, (Osmitrol, Resectisol)
Mefruside, (Baycaron)	Methazolamide, (Apo-Methazolamide, Neptazane)	Methyclothiazide, (Aquatensen, Enduron)	Metolazone, (Mykrox, Zaroxolyn)
Olmesartan and Hydrochlorothiazide, (Benicar HCT)	Polythiazide, (Renese)	Torsemide, (Demadex)	Trichlormethiazide, (Metatensin, Naqua)
Urea, (Amino-Cerv, UltraMide)		Xipamide, (Diurexan, Lumitens)

Taking corn silk with this drug may be harmful:

Warfarin, (Coumadin, Jantoven)—May increase risk of bleeding or bruising.

Disease Effects:

May interfere with the control of blood sugar in diabetes.
May interfere with control of blood pressure in those with elevated or lowered blood pressure.
May worsen cases of potassium loss.

Culinary Uses:

Immature ears are eaten whole as a vegetable. Fresh, unripe seeds are cooked as a vegetable, or roasted and dried for soups, stews, and chili sauces. Cornmeal is used to make polenta, tortillas, tacos, tamales, and enchiladas, and in breads and cakes. Ripe seeds are heated to make popcorn. Fresh leaves and husks are used for wrapping foods, especially tamales.

Economic Uses:

Dried, ripe seeds are processed as cereals and flower (cornstarch, cornmeal, grits, cornflakes), fermented to make alcoholic drinks, such as chicha (beer), or pressed for oil. Corn syrup is extracted from fresh corn and may be blended with molasses.

Bibliography:

The Encyclopedia of Herbs by Deni Bown Copyright © 1995, 2005. Dorling Kindersley Limited. pg 410.
The Essential Herb-Drug-Vitamin Interaction Guide by Geo. T. Grossberg,MD and Barry Fox,PhD Copyright©2007 Barry Fox,PhD Pp.168-169