Aseroe rubra

Description

Aseroe rubra is a widespread basidiomycete fungus recognizable for its foul odor of carrion and its sea anemone shape when mature. Found in gardens on mulch and in grassy areas, it resembles a red star-shaped structure covered in brownish slime on a white stalk. It attracts flies, which spread its spores.

It starts as a partly buried whitish egg-shaped structure 3 cm (1+1⁄4 in) in diameter, which bursts open as a hollow white stalk with reddish arms erupts and grows to a height of 10 cm (3.9 in). It matures into a reddish star-shaped structure with six to ten arms up to 4 cm (1+1⁄2 in) long radiating from the central area.

The top of the fungus is covered with dark olive-brown slime or gleba, which smells of rotting meat and contains spores on its surface. There is a cup-shaped volva at the base that is the remnants of the original egg.

It appears in tropical and subtropical areas. In the United States, Hawaii, and in the southeastern states, where it has been introduced. Also, noted in Australia, New Zealand, and southern Africa.

Despite young ovoid fruiting bodies being edible Ultimate Mushroom does not recommend collecting and eating this fungus.

Common names: Space Alien Fungus, Anemone Stinkhorn, Sea Anemone Fungus, Starfish Fungus.

Mushroom Identification

1. Immature Fruiting Body

   Like a whitish to brownish "egg" up to about 3 cm high; attached to numerous rhizomorphs; when sliced revealing the stinkhorn-to-be encased in a gelatinous substance.

2. Mature Fruiting Body

   Up to about 10 cm high; stem clearly defined, round in cross-section, with a horizontally furrowed surface, white to pink, red, or orange, encased at the base in a whitish volva; head portion flattened, covered with brown to olive-brown, foul-smelling slime; with 5–7 radiating tentacles that are arranged symmetrically around the edge of the head and measure up to about 4 cm long; tentacles doubled, white to pink, red, or orange.

3. Microscopic Features

   Spores 5–6.5 x 1.5–2 µm; cylindric; smooth; inamyloid; hyaline or yellowish in KOH; walls not cyanophilic. Sphaerocysts in stem subglobose; 20–40 µm wide. Volval hyphae interwoven; 2–7 µm wide; branching; smooth; hyaline in KOH; clamp connections not found.

4. Habitat

   Saprobic on plant litter and woody debris; growing alone or gregariously; found in woods or, more commonly, in cultivated areas and compost (in gardens, along paths, and so on); appearing year-round; common in Hawaii and frequently found in the southeastern United States; also found in tropical and subtropical areas across the globe (especially Australia, New Zealand, and southern Africa).

Look-Alikes

1. Clathrus archeri

   There is no stem and its arms are not bifurcated.

2. Lysurus gardneri

   Rare mushroom with a longer stem and whitish fruit bodies.

History

The first native Australian fungus to be formally described, Aseroe rubra was collected in 1792 in southern Tasmania and named by the French botanist Jacques Labillardière.

The scientific name is derived from the Ancient Greek words Asē/αση 'disgust' and roē/ροη 'juice', and the Latin ruber 'red'.

It is a member of the stinkhorn family Phallaceae, although has been placed by some mycologists in a separate family Clathraceae.

Photo sources:

Photo 1 - Author: Forest & Kim Starr (CC BY 3.0)

Photo 2 - Author: Mike Young (CC BY-SA 2.5)

Photo 3 - Author: Liz Popich (Lizzie) (CC BY-SA 3.0)

Photo 4 - Author: Len Worthington (lennyworthington) (CC BY-SA 3.0)

Photo 5 - Author: Rotational (Public Domain)