Spiranthes ochroleuca - Yellow Ladies' Tresses

Spiranthes ochroleuca is a charming garden orchid native to North America. Its local name, "yellow nodding lady's tresses," refers to its unique flowering. The inflorescences comprise dozens of small white-yellow flowers, which appear to be woven in a spiral along the flower stalks. This slightly fragrant botanical species exudes a wild charm that will be welcome in a natural garden. With unwavering hardiness, it grows in sunny to slightly shaded exposure.

The Spiranthes is one of the 850 genera in the Orchidaceae family, the largest in the plant world in terms of number of species (about 25,000!) and one of the most diverse. While most orchids are epiphytic (using trees as supports for growth), there are also garden ones, which, like Lady's Slipper Orchids (Cypripedium) or Spiranthes, grow rooted in the soil. This genus comprises about forty American species, with only three or four originating from Eurasia. It is easily identifiable by its spiral inflorescences (or, more precisely, circular helices).
Spiranthes ochroleuca is a North American botanical species whose natural range covers the entire area from Tennessee and South Carolina to southern Canada (Ontario). It is found in open dry forests, meadows, dry to moderately moist fields and heathlands, roadside edges, and any medium where vegetation is low and sparse. This deciduous perennial plant starts from a fine-rooted rhizome, from which three to five leaves emerge in spring, forming a rosette. The leaves are very elongated, measuring 5 to 21 cm long and 1 to 3-4 cm wide. They have a beautiful medium green colour and a pointed tip. They start from the base, upright, then slightly bend outward. Flowering is late, and it has been blooming in September-October for about a month. A floral stalk forms thin and leafless, reaching up to 50-55 cm in height in some individuals. The upper part is a spike measuring 7 to 12 cm in length. It comprises about fifty small white and yellow flowers, sessile (attached directly to the stalk without a peduncle).

The stalk and flowers are curiously covered with tiny inflorescence. The main unique feature is the flower's spiral arrangement, which appears to form a hair braid. Indeed, the white flowers are laterally curved, thus creating a distinctive pattern with the green floral bracts and miniature transformed leaves (only 15 mm long) at the base of each flower. It is these successive crossings that evoke a braided hairstyle. The flowers measure approximately 15 to 17 mm in length, the sepals from 6 to 14 mm, and the lip (the lower petal), often yellow, from 7 to 12 mm. Petals and sepals, three each, are not spread out as frequently seen in orchids, but close to each other, forming an almost tubular, bent flower that opens into a trumpet at the end. This morphology is perfectly adapted to pollination by bumblebees in its natural range. When flowering is over, the leaves wither, and the plant enters winter dormancy.

Spiranthes ochroleuca will appeal to enthusiasts of botanical species and natural gardens. Planted in the sun, it will find its counterpart in partial shade with the Bletilla striata, another charming garden orchid with small pink flowers beautifully highlighted by light green foliage. Blooming in June-July, this other species will offer you staggered flowering times. Grasses with a countryside look, such as Eragrostis spectabilis 'Great Plains', will also fit well into the spirit of your natural scene. Relatively inconspicuous for part of the year, it transforms in summer, covered with a cloud of pinkish-purple spikelets.