Woodsia obtusa
blunt woodsia
Overview
Woodsia obtusa is a small, tuft-forming fern in the family Woodsiaceae, producing clusters of fronds 8–18 inches (20–45 cm) long from a short, scaly rhizome. The fronds are lance-shaped in outline and twice-divided, with bluntly rounded, toothed lobes that give the plant its common name, blunt-lobed cliff fern. The leaf stalks and undersides bear small glandular hairs, and the round spore cases on the lower surface are partly cupped by tiny star-like membranes. New fronds unfurl in spring, and in milder parts of its range some stay green into winter. It grows on rocky ledges, cliff crevices, talus, and wooded slopes across eastern and central North America, on both acidic and limestone rock. It tolerates the periodic drying of exposed rock by curling its fronds, then refreshing them after rain. Plants are modest in size and spread slowly, forming small colonies in rock seams rather than broad sweeps.
Native Range
Woodsia obtusa is native to eastern and central North America, from Quebec and Ontario south to Georgia and west to the Great Plains and Texas. It grows on rock outcrops and slopes throughout much of this range.Suggested Uses
Woodsia obtusa is used in shaded rock gardens, on stone walls, and in crevice and trough plantings where its small size suits small pockets of soil. It naturalizes into cliff faces and shaded outcrops. It pairs with other small woodland and rock ferns in lightly shaded settings.How to Identify
Appearance
Size & Dimensions
Height8" - 1'6"
Width/Spread10" - 1'6"
Bloom Information
As a fern, Woodsia obtusa does not flower. It reproduces by spores borne in round clusters on the frond undersides, ripening from early summer into autumn. The dust-like spores are released to the wind and germinate on damp, shaded rock and soil.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 2-6 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
Woodsia obtusa grows in part to full shade on well-drained, rocky or gritty soil and is suited to rock gardens, crevices, and shaded walls. It needs steady moisture while fronds are expanding but tolerates short dry spells on its rocky perch. It grows on both acidic and limestone substrates, so soil pH is not limiting. It needs no fertilizer and little care once settled in a suitable crevice. Heavy, wet, poorly drained soil causes the rhizome to rot.Pruning
No pruning is needed. Tattered or winter-burned fronds are cut away in early spring before the new fronds unfurl. No other trimming is required through the season.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons