Strap Coral Identification Guide

The First Impression

Strap Coral is a species you find by looking down at the right forest floor. The setting is a cool, damp conifer wood, often at some altitude, with spruce or fir overhead and a deep, springy carpet of needles underfoot. Scattered through that carpet are dozens, sometimes hundreds, of small pale tongues standing upright, each 3 to 10 cm tall and no more than a finger width across, in warm buff and ochre tones that sit just far enough from the needle colour to catch the eye. A single fruit body is unremarkable and easy to dismiss; a slope covered in them is unmistakable, and gregariousness is itself part of the identification.

Shape and Size

Take one in hand and note that it is simple and unbranched, which immediately separates it from the true corals. It is a club: narrow and roughly cylindrical at the bottom, widening upward into a flattened, strap shaped or spatula like upper portion, and finishing in a rounded or bluntly wedge shaped tip. Many are slightly compressed with a shallow longitudinal groove down one face, and older ones are wavy or twisted. The critical negatives are that the tip is never sharply flattened into a truncated disc with a rim, and the club is never forked or branched, though occasional distorted specimens split shallowly at the apex. Heights of 3 to 10 cm and widths of 5 to 15 mm at the broadest point are typical, with the base often only 2 to 4 mm thick.

Colour and Surface

Colour runs through pale ochre, buff, warm cream, pinkish tan and light cinnamon, generally paler at the base than at the top. Very fresh material may carry a fine whitish bloom that rubs off. With age and drying the whole club dulls and browns, and handled or bruised areas take on a slightly deeper brownish tone without any abrupt or dramatic change. The surface is dry and matt, smooth when young, and developing shallow longitudinal wrinkles as it matures and shrinks. Wet fruit bodies look darker and slightly translucent at the margins.

The Fertile Surface

There is no gill, pore or tooth layer anywhere. The spore bearing tissue is a smooth layer covering the outside of the upper, broadened part of the club, and it simply stops somewhere on the narrower lower portion, sometimes with a faint change in texture marking the boundary. The sterile base is often finely downy and bound with white mycelial threads and needles where it enters the litter. Check this by rolling a club between your fingers: the top half is even and slightly velvety, the bottom is a little rougher and paler.

Flesh and Interior

Slice a club lengthwise. The flesh is white, soft and notably light for its bulk, and the centre becomes loose, cottony or partly hollow in mature specimens, so that a section shows a firm outer wall around a spongy or empty core. It does not have the tough, leathery or fibrous texture of the earthfans, nor the brittleness of the small brightly coloured club fungi. Cut surfaces stay white or dry slowly to a dingy cream, and there is no sharp colour change to record. The odour is faint and indistinct.

Taking a Spore Print

A print from a club fungus takes a little patience but is worth having. Lay several clubs horizontally on a sheet of dark paper or a glass slide over dark paper, cover them with a box or bowl to hold humidity, and leave them six to twelve hours somewhere cool. The deposit falls in a band along the length of the fertile upper part and is white to pale cream, sometimes with a faint ochre cast when heavy. Under the microscope the spores are the confirmation: long, narrowly ellipsoid, smooth, colourless and large, about 12 to 16 by 3 to 5 micrometres, and they do not stain blue in iodine reagents. Spores of that shape and length are unlike those of most agarics and of the coral fungi you might have in mind.

Substrate, Season and Ecology

Strap Coral is a species of conifer needle litter. It comes up through duff under Norway spruce, silver fir and pines, often in mossy, humid, upland or northern forest, and its mycelium runs through the buried needle layer, binding needles into a loose mat that you can see if you lift a patch of litter around a colony. It is a component of the litter processing community of those forests, and it usually appears in troops rather than singly, sometimes in extraordinary numbers along one damp slope while adjacent ground has none. Fruiting runs from late summer through autumn, later at low elevations, and the fruit bodies persist for a week or two, gradually browning and shrivelling. It is widespread across boreal and montane forests of the Northern Hemisphere.

Separating It from Look-alikes

• Clavariadelphus pistillaris is much bigger and heavier, reaching 10 to 30 cm tall with clubs 2 to 6 cm thick, widening to a fat rounded head. It grows in broadleaved woodland, especially under beech, comes singly or in a few scattered fruit bodies rather than dense troops, and discolours brownish or purplish where handled.
• Clavariadelphus truncatus has a head that broadens to a flat, sharply truncated top with a distinct rim, and it is a richer orange ochre. Any flat topped club with a defined edge is not Strap Coral.
• Clavariadelphus sachalinensis and its allies are very close, being similarly narrow conifer litter clubs; separation usually rests on spore length and habitat details rather than field characters.
• Clavulinopsis fusiformis and Clavulinopsis helvola are bright yellow to orange, brittle, tapered to a point rather than broadened at the top, and grow tufted in grassland and mossy ground.
• Clavaria fragilis forms white, extremely brittle, fused clusters of narrow clubs.
• Macrotyphula fistulosa is taller, thinner, tubular and tough elastic, and it grows from buried fallen twigs and branches of broadleaved trees rather than from needle litter.
• Spathularia flavida looks superficially similar but has a flattened yellow paddle sharply set off from a distinct paler stalk, with the fertile tissue running down the stalk as two flanges. Strap Coral tapers gradually and has no defined stalk.
• Ophiocordyceps ophioglossoides has a dark olive to blackish club on a slender stalk arising from a buried truffle like host, a completely different colour and attachment.

A Working Sequence

Confirm the following in order: many small unbranched clubs in conifer needle litter; upper part flattened and strap or spatula shaped with a blunt rounded tip and no truncated rim; ochre to buff colouring, paler below; soft white flesh becoming spongy or hollow in the centre; smooth fertile surface only on the upper portion; and a white to cream spore deposit with long, narrow, smooth spores.