Mushroom Cap Margins
The cap margins are the edge of the cap, where the surface meets the underside. The margins can exhibit specific characteristics that will aid in identification. As the mushroom matures, the margin may change. When examining the cap margin, do you notice anything hanging from them? The partial veil could adhere to the margins of some species. If you see lines on the margins, are they raised, grooved, or smooth? On some species, the margins are translucent, allow you to see through to the gills.
Below you'll find the various characteristics associates with the cap margins.
Types of Cap Margins
Entire
There is a smooth transition from the top of the cap to its underside. No irregular attributes should be present on the edges. Also referred to as Smooth, Even, Seamless, Flush, or Regular.
Appendiculate
Remnants of a partial veil hang from the edge of the cap.
Striate
Fine and narrow stripes run parallel on the cap margins. The lines will often coincide with the gills underneath the cap. In some cases, the lines are only visible when the cap is wet. Also referred to as striped, furrowed, streaked, ribbed, lined, or wrinkled.
Sulcate
Narrow parallel grooves that line the margins of the cap. Sulcate margins are more defined than striate but less ridged than plicated. Also referred to as plicate-striate.
Plicate
Parallel pleated margins. They are best described as fan-like or umbrella-like as if the surface of the cap were folded. Plicate margins are more defined and ridged than Striate or Sulcate. Also referred to as pleated or ridged.
Eroded
Deteriorated, gnawed, or eaten away. The disfigured margins are usually found in older specimens and are the result of insects or deliquescence (common with Ink Caps). Also referred to as gnawed or ragged
Split
The edges of the cap are split apart or full of large crevices. Also referred to as cracked or rimose.
Lacerate
Many tears mark the edge of the cap. Similar to split margins, however, the cuts are smaller and more frequent. Also referred to as torn.
Hairy
The edge of the cap contains many fibrous hairs. Also referred to as tomentose, fimbriate, or fringed.
Undulating
The edges of the cap form a wave-like pattern as they rise and fall. Also referred to as wavy irregular or festoony.
Crenate
Semi-circle notches or round-toothed edges that are more blunted than serrate margins. Also referred to as scalloped.
Serrate
The edges of the cap appear jagged and saw-toothed. More pronounced than crenate margins.
Shapes of Cap Margins
Viewing a cross-section of a mushroom reveals the unique shape of the margins.
Straight
The margins remain uniform and do not curve.
Decurved
The margins curve slightly downwards.
Incurved
The margins curve down and inwards.
Involute
The margins curve downwards and roll inwards. Also known as inrolled.
Arched
The margins curve upwards between the edge and stipe (stem).
Uplifted
The margins curve upwards. Also known as elevated.
Revolute
The margins curve inwards and also rolled back.
Exceeding
The margins extend past the gills.
- DK
