Produces its single leaf in fall, overwinters it, and absorbs it before flowering in summer. Some populations are obligately cleistogamous (flowers never open), abandoning insect pollination entirely.
Eric Hunt, CC BY-SA 4.0, via Wikimedia Commons
An unconventional calendar
The cranefly orchid (Tipularia discolor) operates on a schedule opposite to most plants in its habitat. In autumn, as deciduous trees drop their leaves, this orchid produces a single, distinctive leaf. This solitary leaf is typically ovate, green on its top surface, often with dark purple spots—and a vivid purple on the underside. It measures up to 12 cm long and 8 cm wide. This winter leaf persists through the cold months, lying flat against the forest floor. It takes advantage of the open canopy, photosynthesizing when sunlight can reach it without obstruction. By late spring, as the forest canopy closes, the leaf withers and dies back, its nutrients reabsorbed by the plant's underground corm. For a few weeks, the plant is completely invisible above ground.
A ghostly summer flower
From July to September, long after its leaf has vanished, the orchid sends up a leafless, reddish-brown flowering stalk that can reach heights of 20 to 65 cm. This stalk bears a loose raceme of 20 to 40 small flowers. The flowers themselves are a dull greenish-yellow to purplish-brown, and their shape gives the orchid its common name. The slender sepals and petals are said to resemble the gangly legs of a cranefly.
The flowers are asymmetrical, which is a rare trait for orchids, which are typically bilaterally symmetrical. This lopsided structure is a specific adaptation for pollination by noctuid moths, such as the armyworm moth (Mythimna unipuncta). As a moth probes for nectar in the flower's long spur, a sticky packet of pollen called a pollinium adheres to one of its compound eyes. The flower's slight tilt to the right or left determines which eye receives the pollen packet. The moth then carries this pollinium to the next flower it visits. In some populations, however, the flowers never open, a phenomenon known as cleistogamy. These orchids rely entirely on self-pollination, forgoing their interaction with moths.
Fungi and the forest floor
Tipularia discolor depends on mycorrhizal fungi, particularly during its early development. Its seeds are minuscule and dust-like, lacking the food reserves needed to germinate on their own. They must form a symbiotic relationship with specific fungi found in decaying wood to grow. The orchid seedling, or protocorm, is initially non-photosynthetic and derives all its nutrients by digesting fungal threads. Even after maturing and producing its winter leaf, the orchid often retains its fungal partners. This relationship explains why the orchid is most often found in humus-heavy, acidic soils of deciduous forests where rotting logs and stumps are plentiful.
💡Fun Facts
The species name *discolor* refers to the two different colors of the leaf: green on top and purple underneath.
The plant stores energy in a chain of underground, potato-like corms, which allows it to spread vegetatively.
Seedlings may remain underground for three to seven years before producing their first leaf.
The purple pigment on the leaf's underside is from anthocyanins, which may help with photosynthesis and heat absorption in winter.
Accessible year-round in natural forest habitats. The single leaf is visible from fall through late spring; the flower stalk appears in mid-to-late summer.
Admission
Free
Accessibility
Found in mixed hardwood forests, often on slopes. Access requires hiking on uneven, natural terrain.
