Fluted Black Elfin Saddle

The Fluted Black Elfin Saddle is the dark counterpart of the White Saddle, sharing the same architecture but rendered in smoke grey, slate and charcoal. It belongs to the Helvellaceae, a family of stalked ascomycetes whose fertile surface is exposed on the outside of a saddle, ear or cup instead of being enclosed.

The name lacunosa refers to the lacunae - the pits and hollows - carved into the stalk. Deep rounded ribs run the length of the stem, branching and rejoining to enclose elongated pockets, so that a cross-section looks like a maze of chambers rather than a simple tube.

Molecular work has shown that what was once treated as one widespread species is a complex of several regionally distinct fungi. Helvella lacunosa in the strict sense is now generally applied to European material associated with broadleaf trees, with separate names used for western North American populations.

Head

The fertile head is 2-6 cm wide, irregularly saddle-shaped with two or three lobes that fold, twist and often press back against the stalk. Colour ranges from pale mouse grey through slate to nearly black, usually darkest on the upper spore-bearing surface. The margin is wavy and partly fused to the stem in places.

Surfaces

The upper surface is smooth, matt and the darkest part of the fungus. The underside is paler grey and finely downy or smooth, sometimes showing fine veins running down toward the stalk.

Stipe

3-10 cm tall, 1-2.5 cm thick, grey to blackish-grey, occasionally paler toward the base. It is deeply fluted with rounded longitudinal ribs that fork and reconnect, enclosing conspicuous elongated pits. The interior is chambered rather than a single hollow.

Flesh and spore print

The flesh is thin, greyish-white and brittle, with no colour change when cut. The spore deposit is white, and spores are smooth, ellipsoid and each contain a single prominent oil droplet.

It grows on soil, in leaf litter and among moss in broadleaf and mixed woodland, and often appears on disturbed ground such as path margins, banks, old burn sites, woodchip beds and grassy woodland edges. Beech, oak and other broadleaf trees are typical associates in its European range.

Fruiting runs from summer through autumn, peaking after periods of steady rain, and can continue into early winter in mild seasons. The species is widespread across temperate Europe, with closely related members of the complex occurring in North America and Asia.

Helvella lacunosa is regarded as ectomycorrhizal, forming nutrient-exchanging sheaths around the fine roots of broadleaf trees. The fungus supplies water and mineral nutrients drawn from a wide soil volume and receives carbohydrates from its host, which is why fruit bodies recur under the same trees.

Some members of the wider complex appear opportunistically on burned ground and heavily disturbed soil, suggesting a tolerance for habitats where competing fungi have been cleared. Ascospores are released from the exposed upper surface of the saddle, and the tall fluted stalk raises that surface above the litter layer, improving the chance that spores are carried away on air currents.

Helvella crispa is structurally almost identical but cream to ivory throughout instead of grey-black. Helvella vespertina of western North America is larger and stouter with a thicker fluted stalk and grows with conifers, while Helvella dryophila is a smaller western species found with live oak.

Helvella atra is much smaller, with a dark saddle on a slender stalk that is smooth or only slightly grooved and never deeply chambered. Helvella macropus is grey but cup-shaped rather than saddle-shaped, with a downy, unfluted stalk. Helvella corium is a small blackish cup on a short stalk, again without the branching stalk ribs.