Cypripedium flavum

The alternate Cypripedium flavum, close to C. reginae, is a garden orchid whose flowers, quite variable in their shades, are made up of pale pink to yellow sepals, and a yellow straw to cream lip. Quite rare, although it is vigorous, spectacular and very hardy, it spreads easily in bright green and fresh clumps. Where it thrives, in semi-shade, in moist and rather calcareous soil, it can form large colonies. Like many orchids, it is very easy to cultivate provided that its habitat is meticulously recreated.

The alternate Cypripedium flavum is native to high mountain valleys in western China. It develops there in the humus of valleys and rocky slopes, on a substrate rich in travertine, a limestone rock.

This Venus slipper forms, from spring onwards, a clump of large bright green leaves, oval to elliptical, with very pronounced parallel veins. In nature, it can reach up to 60cm (24in) in height. In our climates, it will reach 40 to 50cm (16 to 20in) in height. Flowering occurs in early summer, it is sometimes absent in certain years, and occurs when the plant is at least 4 or 5 years old. The solid and robust floral stem, measuring between 30 and 40cm (12 and 16in) in height, develops directly from a very large cylindrical rhizome. It is equipped with leaves up to the top. Alternating and distributed along these tall stems, one or two flowers appear, rarely 3 or 4. It has been observed that flowering is more generous when the soil is rich in calcium carbonate. They have the characteristic shape of Cypripedium flowers, and measure 4 to 6cm (2in) in diameter. They are quite variable, more or less yellow and more or less speckled with purple brown. They are composed of cream or pink sepals and petals, spotted with brown, dominating an imposing 'slipper' lip, very swollen, pale yellow to white depending on the plants. Note that the entire vegetation is covered with a fine down that can be allergenic and irritating to the skin. These urticating hairs are hosts to a fungus. During winter, the foliage disappears and the plant persists in the form of a rhizome.

The alternate Cypripedium flavum is demanding in terms of its habitat, but if the conditions are met, it will be a real attraction for the cool areas of the garden and the pride of the gardener who has managed to acclimatize it. It can be installed in clear undergrowth or at the edge of undergrowth, on the edge of a water feature, in semi-shade, in a carefully prepared substrate. It will associate well with ferns, hostas, and Rodgersias.

When you receive your orchids, handle them with care: these plants produce few roots and are delicate!