Pellaea atropurpurea
purple-stem cliffbrake
Overview
Pellaea atropurpurea is a small, evergreen, rock-dwelling fern of the brake family native to limestone cliffs, ledges, and rocky slopes across much of North America. It forms tufted clumps 6-18 inches (15-45 cm) tall from a short, scaly rhizome, with stiff, wiry fronds rising on dark purple to blackish stalks that give the species its name. The leathery, blue-green, once- to twice-pinnate blades bear oblong segments 0.3-1 inch (8-25 mm) long, with fertile fronds taller and more divided than the sterile ones. Spore-bearing structures line the rolled-under margins on the underside of fertile segments. As a calciphile of dry rock, it grows in crevices with sharp drainage and tolerates heat and drought that few ferns endure, drawing moisture from limestone seeps. It is slow-growing and intolerant of wet, acidic, or rich soils, where the roots rot, which limits where it can be grown. In cultivation it is used in rock gardens, crevice plantings, troughs, and on dry stone walls in lime-rich, gritty media in part shade to sun.
Native Range
Native to North America from southern Canada through the United States to Mexico and Guatemala, most common on limestone and other calcareous rock. It grows in crevices of cliffs, ledges, and boulders, and on rocky, lime-rich slopes.Suggested Uses
Used in rock gardens, crevice gardens, troughs, and on dry limestone or mortared stone walls in lime-rich, gritty media. It suits xeric and alpine plantings where soft ferns fail.How to Identify
Appearance
Size & Dimensions
Height6" - 1'6"
Width/Spread6" - 1'
Colors
Foliage Colors
Fall Foliage Colors
Bloom Information
As a fern, it produces no flowers. It reproduces by spores borne along the rolled margins on the undersides of fertile fronds. Spores ripen from summer into autumn.
Detailed Descriptions
Foliage Description
blue-greenGrowing Conditions
Sun Requirements
Requires 3-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in gritty, sharply drained, alkaline media in part shade to full sun, set into rock crevices or a limestone wall. The species needs lime and dry conditions at the root, and rots in wet, acidic, or rich soils. Water lightly during establishment, then only in extended drought; it tolerates heat and dryness once settled. The fronds are evergreen and persist through winter in mild areas. It is slow to establish and does not transplant well once settled. Hardy in USDA zones 5-9.Pruning
No routine pruning is needed. Tattered or winter-burned fronds can be trimmed away in early spring before new growth unfurls. The evergreen fronds are otherwise left in place.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons