Stropharia semiglobata

🏷️ Description

This cosmopolitan mushroom, commonly called the Dung Roundhead, thrives on the dung of herbivores like cows, rabbits, moose, and even wallabies! Found across grasslands, lawns, and livestock corrals worldwide—from North America to Australia—this fungus favors manure-rich environments, often fruiting alongside other dung-loving species like Deconica coprophila. 🌾🐄

🔍 Key Features:

• Cap: Hemispherical, viscid (sticky), and straw-yellow to buff-tan in color.

• Gills: Start grayish, darkening to rich brown as they age.

• Stem: Slender, smooth, with a fragile, glutinous ring.

• Spores: Purple-brown, aiding in identification.

🍄 Edibility: While some guides list it as edible, others caution against consumption due to its dung-dwelling nature and potential toxins. When in doubt, treat it as toxic. ⚠️

🔬 Taxonomy & History: First described in 1786 by August Batsch as Agaricus semiglobatus, the species journeyed through various genera before French mycologist Lucien Quélet placed it in Stropharia in 1872. In 2013, Scott Redhead and colleagues proposed the genus Protostropharia, distinguishing it by unique astrocystidia (star-shaped cells) on its mycelium. Its name reflects its traits: "proto" (first) + "stropharia" (belted, referencing its ring), while "semiglobata" means "half a globe."

🌟 Fun Fact: Sometimes, this mushroom pops up on moss-covered dung, creating the illusion of growing straight from moss! 🍃

📍 Global Explorer: Spotted in Asia, Europe, the Americas, Australia, New Zealand, and beyond, Protostropharia semiglobata is a true world traveler, possibly hitching rides with livestock over centuries. 🚜🌏

📜 Common names: Dung Roundhead, The Halfglobe Mushroom, Hemispheric Stropharia.

🔎 Identification

🎩 Cap: The cap is hemispherical to convex, ranging from 1–4 cm (0.4–1.6 in) wide. Initially a light yellow, it matures to a dull yellow or whitish. The surface is smooth, viscid (sticky when moist), and glossy when dry.

🍂 Gills: The adnate gills attach to the stem with a slight decurrent tooth. Starting as grayish, they mature into a purplish-brown to dark purple, edged with white, fringed margins. The gills are broad and distantly spaced, giving them a distinct appearance.

📏 Stem: A slender, tall stem reaches 3–12 cm (1.2–4.7 in) in length and 0.2–0.5 cm (0.1–0.2 in) in width. It features a bulbous base, a delicate ring zone often darkened by spores, and a surface that is silky above the ring and sticky below. The stem flesh is white with a yellowish core and transitions from stuffed to hollow as it matures.

🦠 Spores & Spore Print: Producing a dark purple-brown spore print, the spores are ellipsoidal to ovoid, measuring 15–20 x 7.5–11 µm. They have a thick wall and an apical germ pore, adding to their microscopic beauty.

👃👅 Odor & Taste: The mushroom lacks a distinctive odor and has a mild to slightly bitter taste, though its edibility is debatable, with some sources listing it as inedible or potentially toxic.

🌍 Habitat & Ecology: This saprobic species thrives on animal dung and freshly manured fields, often appearing after rainy periods. It grows solitarily or in small groups and is widely distributed across North America, Europe, Asia, and beyond.

👀 Look-Alikes

1. Panaeolus semiovatus

   Also occurs on dung; it retains its stem ring and provides a black spore print.

2. Deconica coprophila and its close cousin Deconica merdaria

   Differs in having reddish-brown to brown sub-viscid caps and lack of a ring.

3. Panaeolus papilionaceus

   Has a grayish-brown, fringed, non-viscid cap and also lacks a ring.

4. Panaeolus semiovatus

   Larger, annulate species with a cream-colored, distinctively wrinkled, viscid cap.

5. Stropharia coronilla

   Differs in possessing a non-viscid, striate-margined annulus, and has brown, not purple-brown gills and spores.

6. Bolbitius titubans

   Occasionally fruits on dung. It has a viscid, yellowish cap with a striate margin, ochre-colored gills, and lacks a veil.

📜 Synonyms

• Agaricus glutinosus Curtis (1781)

• Agaricus semiglobatus Batsch (1786)

• Agaricus lustre Bulliard (1792)

• Agaricus praecox Schumacher (1803)

• Hypophyllum cereum Paulet (1808) [1793]

• Agaricus virosus Sowerby (1815)

• Coprinus semiglobatus (Batsch) Gray (1821)

• Psalliota semiglobata (Batsch) P. Kummer (1871)

• Geophila semiglobata (Batsch) Quélet (1886)

• Anellaria semiglobata (Batsch) J. Schröter (1889)

• Fungus semiglobatus (Batsch) Kuntze (1898)

• Fungus glutinosus Kuntze (1898)

• Psilocybe semiglobata (Batsch) Noordeloos (1995)

• Protostropharia semiglobata (Batsch) Redhead

Photo sources:

Photo 1 - Author: Dr. Hans-Günter Wagner (CC BY-SA 2.0)

Photo 2 - Author: Jason Hollinger (CC BY-SA 3.0)

Photo 3 - Author: Dr. Hans-Günter Wagner (CC BY-SA 2.0)

Photo 4 - Author: Dr. Hans-Günter Wagner (CC BY-SA 2.0)