Climacodon septentrionalis

C. septentrionalis was originally described by Elias Magnus Fries in 1821 under the genus Hydnum.[4][5] It was later transferred to Climacodon in 1881 by Petter Karsten.[6]

Underside of a C. septentrionalis cap with spines.

Individual caps are semicircular or kidney-shaped and can reach up to 30 cm across and 2.5-5.0 cm at the base.[2][3] They typically occur in large groups that can reach 80 cm in height.[2][3] Young caps range from mostly white to a yellow-cream color, and slowly become a yellow-brown as they age.[2][3] Although, the caps tend to persist for multiple weeks, allowing algae to grow, giving them a slightly green appearance.[3] The surface of the cap can be rough or even hairy, and can have concentric rings radiating out from the base.[3] The underside of the cap has many white spines (see left) that reach 1 cm in length and also yellow with age.[2] C. septentrionalis is edible but not palatable due to its tough flesh and bitter taste.[2][3] They can be found in the summer months and are a common cause of heart rot in hardwood trees in their native range.[2][3]

This species is native to northeastern North America, ranging from southern Canada to Kentucky, and as far west as the Great Plains.[2][3][7] C. septentrionalis is found on the trunks of living and recently deceased trees, especially beech (Fagus) and maple (Acer) species.[2][3]

C. septentrionalis was the first observed species fungus not in the genus Agaricus to secrete a toxin that it uses to immobilize and kill fungiphagous nematodes.[8][9] The mycelium of this species grows secretory cells the protrude outwards and develop branches that produce the substance in small droplets.[8] When a nematode comes in contact with a droplet, they become encased in it, and their motion is completely inhibited.[8] Death after contact occurs within several hours, but the rate at which a nematode was decomposed varied greatly, ranging from a few weeks to several days.[8]

C. septentrionalis has been found to produce a few different compounds that have potential to be used for a variety of products.[10] Esters are natural or synthetic, fragrant compounds that can be found in perfumes and flavorings, or used in paints, solvents, insecticides, and more.[11] The mycelium of this species produces esters that could be used in perfumes.[10][11] The compound furaneol is a commonly used in the cooking industry as a flavoring, with different forms having tastes ranging from a strawberry or pineapple to a caramel or honey flavor.[12] The furaneol found in C. septentrionalis is extracted from its fruiting bodies, and has a strawberry-like flavor and taste.[10]