Paphiopedilum concolor aka One Colored Paphiopedilum

Paphiopedilum concolor is an evergreen orchid in the Orchidaceae family. It comes from southern China and parts of Indochina. Its Chinese range includes southern Yunnan, southern Guizhou and western Guangxi. It grows in a wet tropical climate. This perennial can grow on rock or in partly terrestrial sites.

The plant forms clumps of leafy rosettes. In cultivation, its height and spread reach 0.3–1.6 feet [0.1–0.5 metres]. Plants take two to five years to reach full size. Each rosette has four to six firm, oval leaves. Dark green leaves show a pale green, net-like pattern. Purple spots mark their undersides. Leaves measure about 0.3–0.5 feet [0.10–0.15 metres] long. Their width is about 0.10–0.13 feet [0.03–0.04 metres]. The patterned leaves give interest beyond the flowering season.

Flowers appear in spring and summer on upright stems. These rise from the centre of each leaf rosette. The stems reach about 0.3 feet [0.10 metres] long. Each usually bears one flower, though two or three may appear. Each bloom spans about 0.23 feet [0.07 metres]. Rounded petals and sepals have a pale yellow base. Many maroon or purple spots cover their surface.

Grow this orchid indoors, in a conservatory or heated greenhouse. The RHS rates it H1A, for year-round growing under glass above 15°C. Give it bright, filtered light and more humidity in summer. Suggested summer temperatures are 20–25°C, with 18–22°C in winter. Use a bark-based mix made for terrestrial orchids. Add sphagnum moss and perlite, or crushed limestone chips. The RHS lists a neutral pH and good drainage. Water when the mix nears dryness, before it stays dry too long. The plant has no pseudobulbs to store water. Do not leave the pot standing in water. Avoid keeping the mix wet for long periods. Feed with every third watering.

This orchid needs no pruning and has few reported pest problems. Mealybugs may still attack it. Cold conditions and overhead watering can cause bacterial rot in rosette centres. Avoid heavy misting and watering from above. Divide mature clumps when they outgrow their pots. Keep at least three healthy, rooted rosettes in each division. These help support fresh growth after repotting. Raising plants from seed needs controlled laboratory conditions.