Stropharia melanosperma

What You Should Know

Stropharia melanosperma is a fungal species that was first described by Pierre Bulliard (1742–1793), and got its current name from Claude-Casimir Gillet in 1878. Stropharia melanosperma is part of the genus Kragskivlingar and the family Strophariaceae. It is widespread in North America but not often reported. Grows in grassy areas and fertilized landscaping areas.

Distinguishing features include the white cap fringed with tooth-like veil remnants, the whitish-then-gray gills, the white ring that features a lined upper edge, and microscopic features, including fairly large spores with a slightly truncated end and chrysocystidia.

"Stropharia melasperma" is an alternate spelling.

Stropharia melanosperma Mushroom Identification

1. Ecology

   Saprobic, growing scattered to gregariously in grassy areas; usually found in parks, lawns, gardens, landscaping areas, and waste places; widely reported in North America.

2. Cap

   2–5 cm; convex at first, becoming broadly bell-shaped or nearly flat; sticky when fresh; bald or very finely fibrillose; whitish overall, with a very pale, dull yellowish center—or sometimes pale straw color overall; the young margin scalloped with white, tooth-like partial veil remnants.

3. Gills

   Narrowly attached to the stem; close; short-gills frequent; whitish to very pale purplish-gray at first, becoming purplish gray; edges colored like the faces.

4. Stem

   4–8 cm long; 4–7 mm thick; equal above a slightly swollen base; bald or very finely fibrillose in places; with a high, tight ring that features a lined upper edge and which catches grayish-purplish spore dust in mature specimens; whitish; basal mycelium white.

5. Flesh

   White; unchanging when sliced.

6. Odor

   Not distinctive, or slightly foul and reminiscent of coal tar.

7. Chemical Reactions

   KOH on cap surface pale orangish pink.

8. Spore Print

   Dark purplish gray.

9. Microscopic Features

   Spores 10–13 x 6–7.5 µm; more or less ellipsoid, with one end, slightly truncated by a 1–1.5 µm pore; smooth; yellow-brown in KOH; thick-walled. Basidia 4-sterigmate. Chryso-cheilocystidia abundant; 30–40 x 5–10 µm; widely fusiform, becoming rostrate with a small extension; hyaline in KOH; thin-walled; often with yellowish-refractive inclusions. Chryso-pleurocystidia scattered; similar to chryso-cheilocystidia. Lamellar trama parallel. Pileipellis a cutis; hyaline in KOH; elements 2.5–7.5 µm wide, smooth.

10. Similar Species

    Stropharia coronilla is very similar but can be separated by its stockier stature, darker cap, and, more definitively, its smaller spores.

Stropharia melanosperma Synonyms

1. Stropharia melanosperma (Bull. ex Pers.: Fr.) Gillet, Hymén. Fr.: 579 (1874)

2. Agaricus melanospermus Bull., Hist. Champ. Fr.: pl. 540, fig. 2 (1792)

3. Agaricus melanospermus Bull. ex Pers., Syn. Meth. Fung.: 420 (1801)

4. Agaricus melanospermus Bull. ex Pers.: Fr., Syst. Mycol. 1: 283 (1821)

5. Geophila melanosperma (Bull. ex Pers.: Fr.) Quél., Enchir. Fung.: 111 (1886)

6. Psilocybe melanospermus (Bull. ex Pers.: Fr.) Noordel., Persoonia 16: 129 (1995)

Sources:

Photo 1 - Author: Jon (watchcat) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Jon Shaffer (watchcat) (Creative Commons Attribution-Share Alike 3.0 Unported)