Begonia masoniana aka Iron Cross Begonia

Begonia masoniana is known as iron cross begonia. It belongs to the begonia family, Begoniaceae. Its native range runs from Guangxi in China to Vietnam. It grows in a wet tropical climate. This tender perennial grows from a rhizome and keeps its leaves year-round. Gardeners grow it chiefly for its bold leaf pattern.

Plants form dense, upright clumps with a broad outline. They reach about 1–1.5 feet (0.30–0.46 m) tall and wide. RHS gives an upper size of about 1.6 feet (0.5 m). The bright green leaves have uneven sides and toothed edges. They reach about 0.67 feet (0.20 m) long. Each leaf has a dark brown, cross-shaped mark near its centre. Raised bumps give the surface a rough, puckered feel. A small red hair grows from each bump. The leaves provide colour through winter.

Small greenish-white flowers appear in spring and summer. They grow in branching clusters held above the leaves. Each flower measures about 0.06 feet (0.02 m) across. The foliage remains the main reason to grow this plant. It suits pots, indoor displays, and sheltered summer patios. In most climates, gardeners keep it as a houseplant. It can spend warm summers outdoors but needs protection from cold. USDA zones 11–12 suit year-round outdoor growth. RHS rates it H1B, for summer outdoor use.

Indoors, give it bright light without harsh direct sun. It prefers warmth around the low 70s°F and high humidity. Sources warn against temperatures below 55°F. Use a rich potting mix that holds moisture but drains well. Keep the soil evenly moist while the plant grows. Reduce watering when growth slows, letting the surface almost dry. Avoid excess water, and keep the leaves dry. A water-filled gravel tray can raise humidity around the pot. No routine pruning is needed. Leaf cuttings or rhizome sections can produce new plants.

Possible pests include aphids, mealybugs, mites, thrips, and vine weevils. Caterpillars may also attack it. Slugs and snails can reach outdoor pots on the ground. Diseases include leaf spot, blight, grey mould, and powdery mildew. Rot can affect the stems, crown, and rhizome. This is an ornamental plant, not a food crop. Its sap can irritate skin. Soluble calcium oxalates make it harmful to pets. Dogs and cats may vomit or drool after eating it. Grazing animals may suffer kidney failure. The underground parts pose the greatest risk.