Florivern Herbarium · Sheet HERB-07
Det. — species determination
Adiantum raddianum
Delta Maidenhair Fern
Fam.
Pteridaceae
Lithophytic vascular cryptogam with lustrous ebony stipes and fan-shaped hydrophobic pinnae that shed water droplets like mercury.
Hab. — where it grows wild
Shaded wet limestone cliffs and stream banks of the Neotropics
HERB-07
Characters
Group
Architectural Palms & Ferns
Setting
Indoor
Size class
Tabletop / Compact (< 40 cm)
Temperament
Specialist / Collector
Animals
Pet Safe (ASPCA Non-Toxic)
Sheet II — Conditions of cultivation
How it has been grown,
and what changes it.
Delicate one-cell-thick pinnae desiccate irreversibly if the rhizome dries out even once. Keep the substrate continuously moist—comparable to a wrung-out natural sponge—using a self-watering terracotta reservoir or daily inspection in dry seasons.
65% – 85% RH
16°C – 24°C (60°F – 75°F); keep away from heating vents
Air temperature as recorded for this species in cultivation. Cold drafts matter more than the average.
Humus-rich, moisture-buffering fern substrate: 50% fine coco peat, 25% composted leaf mold, 15% fine perlite, 10% calcareous grit.
Height 30–45 cm; arching black-wired rachis fronds
Sheet III — Animals and households
If a cat, a dog or a child shares the room
Recorded non-toxic
Listed as non-toxic to cats and dogs. Non-toxic is not the same as edible — chewed leaves can still upset a stomach.
The record
True maidenhair ferns (Adiantum spp.) are non-toxic to cats and dogs.
Florivern is a herbarium and a shop, not a veterinary authority. If you suspect a plant has been eaten, call your veterinarian or an animal poison control line.
Sheet IV — Monograph
Notes toward cultivation
Lithophytic Seepage Ecology
Adiantum raddianum colonizes calcareous rock seeps where its creeping rhizomes stay perpetually bathed in oxygenated moisture while its fronds remain dry in moving humid air. If superficial fronds crisp due to a missed watering, prune stems to the crown and maintain steady moisture to regenerate new crosiers.
A fern that must not dry out
Maidenhair fronds are extremely thin, and they shrivel quickly once the roots dry. At the same time, the plant dislikes sitting in water. The goal is soil that stays consistently moist but never waterlogged.
In cultivation
Give bright, indirect light without direct sun, steady temperatures and high humidity. A bathroom with a window, a terrarium or a group of plants can help. Water whenever the surface begins to feel dry, and keep it away from heating vents and drafts.
Recovery after drying out
If fronds crisp after a missed watering, the plant is often not lost. Cut the damaged fronds back to the base, keep the soil evenly moist and wait; new fiddleheads can rise from the rhizome within weeks.
Propagation
The easiest method is division: in spring, separate a well-rooted clump into sections, each with its own rhizome and fronds, and pot them up in a moisture-retentive mix.
Supplementary plates
Plates show cultivated individuals, not a type specimen. Leaf form, color and habit vary between plants of the same species.
Sheet V — Cited in the Journal
Further reading on this plant
Held in the Store
Specimens and materials
Shigaraki Reduction-Fired Cylinder Vessel
In Stock
$120
Forged Sanjo Carbon-Steel Satsuki Shears
Low Stock
$88
Each specimen is an individual plant; size and form differ from the plates on this sheet.