Wall Fern or Polypody of the Oak (Polypodium quercinum) – Original Hand-Colored Engraving by Elisabeth Blackwell

This refined botanical engraving depicts the Wall Fern, also known as the Polypody of the Oak (Polypodium quercinum), presenting several mature fronds arising from a creeping rhizome, with clear views of leaf structure and fruiting surfaces.

The fronds are rendered with measured symmetry and a leathery texture, their rounded lobes arranged along a central midrib. Elisabeth Blackwell emphasizes diagnostic features by including multiple fronds at different stages, as well as detailed views of the underside of the leaves, where the sori are clearly visible.

Produced in the early eighteenth century, this plate forms part of A Curious Herbal, a work notable for its careful documentation of ferns and cryptogams—plants of recognized medicinal value despite their lack of flowers and complex modes of reproduction.

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Visual and Aesthetic Analysis

The composition is horizontally grounded by the creeping rhizome, from which upright fronds emerge in a balanced sequence. This arrangement conveys both stability and organic growth, guiding the eye naturally across the plate.

Restrained hand-colouring accentuates the fronds’ texture and form rather than decorative effect. Subtle green tonal variations articulate the leaf surfaces, while the darker rhizome and fine roots provide visual anchoring and structural contrast.

About the Subject

The wall fern, historically referred to as Polypodium quercinum, commonly grows on tree trunks, stone walls, and rocky substrates, particularly in association with oak trees. In early European medicine, its creeping rhizome was valued for expectorant and cleansing properties and was used in preparations for respiratory and digestive ailments. As with many ferns, correct identification depended on leaf shape, sori placement, and root structure rather than flowers. Blackwell’s detailed depiction reflects this practical medical focus, presenting the plant as a functional medicinal resource rather than a purely ornamental subject.

Condition Report

The engraving is in very good antique condition, printed on original handmade laid paper typical of early 18th-century botanical publications. The surface remains stable, with light, even age-related toning. A few very small and fine colour smudges are visible in the upper right area, along with a small light green stain measuring approximately 1 cm in diameter in the same area. These minor marks are unobtrusive and consistent with historical hand-colouring and handling. The impression remains clear and well defined, with intact engraved inscriptions, including the artist’s credit “Eliz. Blackwell delin. sculp. et pinx.”

Details

• Artist: Elisabeth Blackwell
• Work / Publication: A Curious Herbal
• Period: 1737–1739
• Technique: Original copper engraving, drawn, engraved, and hand-colored by Elisabeth Blackwell
• Paper: Original handmade laid paper
• Watermark: None observed
• Sheet size: approx. 37 × 22 cm

For further context on Elisabeth Blackwell and the medical significance of ferns and cryptogams in A Curious Herbal, see our editorial feature:

Elisabeth Blackwell – A Curious Herbal