History.—The term Maidenhair or Capillary (Capillaris, Apuleius; Capillaire, Fr.) has been applied to several species of fern which have been used in medicine. Dioscorides (lib. iv. cap. 136 and 137) and Pliny (lib. xxii. cap. 30) notice two kinds, one termed Adianton, Polytrichon, or Callitrichon (αδιαντον, πολυτριχον, καλλιτριχον), the other called Trichomanes (τριχομανες). The former is supposed by Sibthorp [Prodr. fl. Graecae, vol. ii.] to be the Adiantum Capillus Veneris, Linn., or True Maidenhair, the latter the Asplenium Trichomanes, Linn. Common Maidenhair Spleenwort of modern botanists. In later times, other ferns have been also employed under the name of Maidenhair; especially Asplenium Adiantum nigrum, Linn, or Black Maidenhair Spleenwort; Asplenium Ruta muraria, Linn. Wall-rue or White Maidenhair, formerly called Salvia Vita; Ceterach officinarum, DC., or Rough Spleenwort; and Scolopendrium vulgare, Smith, or Common Hart's-tongue. To these must be added, Adiatum pedatum, Linn, or Canadian Maidenhair, and Adiantum trapeziforme, Linn, or Mexican Maidenhair.
The only species which it will be necessary here to notice are, Adiantum Capillus Veneris and A. pedatum.
Botany. Gen. Char.—Sporangia placed on the distinct points of the veins in a linear or point-like receptacle, arranged in marginal sori. Indusia continuous with the edge of the frond, united to the receptacle, opening inward (Endlicher).
1. A. Capillus Veneris, Linn.; Frond bipinnate, pinnules thin, membranaceous, obovate-cuneate, inciso-sublobate, segments of the fertile pinnules terminated by a linear oblong sorus, sterile ones serrated (Hooker).—Indigenous. Perennial. May—September.
2. A. pedatum, Linn. Frond pedate, divisions pinnate, pinnae halved, oblong lunate, incised at the upper edge, the sterile segments toothed; sori linear, petiole smooth.—North America.
Description.—The officinal part of Maidenhair is the frond, or rather the whole plant without the root.
The herb of True Maidenhair (herba capillorum veneris) is sold at herb-shops in the dried state. When rubbed, it has a feeble odour, and its taste is sweetish and bitterish.
The herb of Canadian Maidenhair (herba capillorum veneris canadensis vel adianthi pedati) is more aromatic than the preceding.
Composition.—No analysis has been made of these species of Adiantum. The most important constituents appear to be tannic or gallic acid, bitter extractive, and a volatile oil.
Effects and Uses.—None of the sorts of Maidenhairs appear to be endowed with any active powers; though a great variety of imaginary properties have been ascribed to them. They are mucilaginous, bitterish, somewhat astringent, and aromatic substances; and in modern times have been used as pectorals in chronic catarrhs. The Canadian Maidenhair (Adianthum pedatum, Linn.) is the most esteemed sort, on account of its stronger and more agreeably aromatic qualities.
A Syrup of Maidenhair (Syrupus Adianthi; Syrupus Capilli Veneris; Sirop de Capillaire), prepared by adding sugar and orange-flower water to an infusion of Maidenhair, has long been popular. Both Baumé and the French Codex direct it to be prepared with the Canadian Maidenhair. When diluted with water, it forms a very refreshing beverage. But as the Maidenhair serves no essential purpose in this drink, it is usually omitted, and the syrup sold in the shops under the name of capillaire is nothing but clarified syrup flavoured with orange-flower water. The Prussian and Hamburgh Pharmacopoeias authorize this substitution by giving formulae for a syrupus florum aurantii to be used in "loco syrupi capillorum veneris."
The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1853.