Osmunda regalis L.

Royal Fern

© SRTurner

Family - Osmundaceae

Habit - Perennial, rhizomatous, homosporous.

Leaves - To 1.5 m. Petioles with scattered scales and matted tufts of hair near the base, becoming mostly glabrous with age. Blades 2 time pinnately compound, ovate in outline. Pinnae lacking tuft of hairs at base. Vegetative pinnae mostly spreading, unlobed, with minutely toothed margins. Fertile pinnae usually produced at the tip of otherwise vegetative leaves.

	Leaves.
© SRTurner

	Leaflets, adaxial.
© SRTurner

	Leaflets, abaxial.
© SRTurner

	Leaf rachis.
© SRTurner

	Fertile pinnae.
© SRTurner

	Sporangia.
© SRTurner

	Mature sporangia.
© SRTurner

Sporulating - May - September.

Habitat - Acid seeps, shaded bluffs on sandstone and granite, bottomland forests in sandy substrate.

Origin - Native to North America.

Other info. - With its large leaves bearing large, discrete pinnules, this is one of the easier of Missouri's ferns to recognize. The sporangia are borne in clusters at the tips of fertile fronds, rather than underneath the pinnules. The plant is generally found on acidic substrates.

Photographs taken at LaBarque Creek Conservation Area, Jefferson County, MO, 6-21-2011, and at Don Robinson State Park, Jefferson County, MO, 4-23-2017, 5-18-2017, and 4-26-2019 (SRTurner).