Microsorum scolopendria aka Monarch Fern

Microsorum scolopendria is a fern in the polypody family. It is perennial, so it lives for more than one year. Garden sources also call it Phymatosorus scolopendria. Common names include wart fern, monarch fern, and serpent fern. It comes from tropical and subtropical parts of the Old World. Its home range spans Africa, Asia, Australia, and Polynesia. It grows in places with a dry tropical season. People have brought it to Florida, Bermuda, and Puerto Rico.

Garden plants reach 1–2 feet [0.30–0.61 metres] tall and wide. This width does not set the limit of their spread. Creeping stems, called rhizomes, can grow past the first clump. Dark brown to black scales cover these stems. Hairy roots grow from them. Plants spread over soil and can climb walls or trees. They also grow on rocks or as epiphytes, on other plants. Fronds hang down over the sides of baskets.

The smooth, leathery fronds can be light to dark green. They reach about 1.3 feet [0.41 metres] long and wide. Full-grown fronds have deep lobes along each side. Young fronds have a single blade with no lobes. Their shape ranges from oval to a narrow egg shape. The midrib and main veins stand out on both sides. This fern does not bloom. Rusty or orange-brown sori form on the fronds' lower side. These round or oval structures form uneven rows. They lie beside the midrib and sink into the blade. The top of the blade bulges above them. These bumps give wart fern its name.

Give this fern moist soil that drains well. Soil rich in organic matter suits it. North Carolina State advises part shade to deep shade. Missouri Botanical Garden also lists full sun to part shade. Both sources list USDA zones 10–11 for winter hardiness. Chicago Botanic Garden lists zones 6–11, a much wider range. The fern likes high humidity when grown indoors. Once plants take root, they can cope with some drought. They still prefer moist soil. Divide the rhizomes to make new plants.

Use it as ground cover where winters stay warm. It also suits beds, pots, hanging baskets, and indoor growing. Cut fronds add green leaves to displays of flowers. Sources report no major insect or disease problems. Its spread needs more care than its pests do. Plants can escape gardens and take root beyond planted areas. North Carolina State reports that it grows invasively in Hawaii's Haleakala National Park.