Clathrus columnatus

The species was first named by the French botanist Louis Augustin Guillaume Bosc in 1811.[1] Christian Gottfried Daniel Nees von Esenbeck transferred it into Laternea in 1858, a genus intended to accommodate those Clathrus-like species with arms arranged in columns rather than a network;[2] in its current meaning, Laternea includes species that have gleba suspended below the arch of the receptaculum by trabeculae (columns that extend from the peridium to the central core of the receptaculum).[3] Other genera to which the species has been transferred include Linderia by Gordon Herriot Cunningham in 1932,[4] Colonnaria by Eduard Fischer in 1933, and Linderiella by Cunningham in 1942. Colonnaria, Linderia and Linderiella are now considered obsolete genera, as they have been subsumed into Clathrus.[5][6][7]

The specific epithet columnatus is Latin, meaning "supported by pillars".[8] The mushroom is commonly known as the "column stinkhorn".[9] Curtis Gates Lloyd wrote in 1906 "in Florida, it is known to the natives as "Dead Men's Fingers."[10] however in recent times Dead Men's Fingers usually refers to Xylaria polymorpha.

Mature specimens showing the dark-colored gleba

The fruit body, or receptaculum, of Clathrus columnatus consists of two to five (usually four) spongy vertical columns, which are separate where they arise from the volva, but joined at the top in an arch. The columns are joined in pairs; the opposite pairs are joined by a short and broad arch similar in structure to the columns. The columns, which are narrower at the base than above, are reddish-orange above and yellowish-pink below. Young specimens have the fruit body compressed into the small interior space of an "egg",[11] which consists of a peridium that is surrounded by a gelatinous layer that encloses the compressed fruiting body. The egg, usually gray or grayish-brown,[11] typically reaches diameters of 3 to 5 cm (1.2 to 2.0 in) before the columns grow. The volva remains at the base of the fruit body as a thick, loose, whitish sack. The mycelial cords found at the base of the volva are made of two types of tissues: a central bundle of fine hyphae that extend in a longitudinal direction, and an outer cortical layer of coarser hyphae that form a loose but highly interwoven structure. Full-grown columns can extend to 5 to 8 cm (2.0 to 3.1 in) above the ground, a location that optimizes spore dispersal. The fetid-smelling gleba, the spore-bearing mass, is smeared on the upper inner surface of the columns.[12]

The spores are elliptical, smooth, and have dimensions of 3.5–5 by 2–2.5 µm.[11] They have thin walls, and are covered by a transparent envelope.[13]

Similar species

Clathrus ruber

Pseudocolus fusiformis

Pseudocolus fusiformis, Clathrus bicolumnatus, and C. ruber have similarities to Clathrus columnatus. The lattice stinkhorn, C. ruber, has a larger, more globular, lattice-like receptacle. The "stinky squid", P. fusiformis, has arms that are attached at the bases, and free at the top. It grows on rotting logs and chip-mulched soil, in contrast to C. columnatus, which grows on sandy soil.[9] C. bicolumnatus has a smaller stature (up to 9 cm tall), and only has two columns.[11]

The American botanist Edward Angus Burt published a detailed description of the development of C. columnatus in 1896. He found that the egg consists of cortical and medullary systems continued upward from the mycelial strand in the earliest stage. The cortical layer gives rise to the outer layer of the volva, the cortical plates and the pseudoparenchyma (thin-walled, usually angular, randomly arranged cells that are tightly packed) of the receptaculum. The medullary portion gives rise to the gelatinous masses of the gelatinous layer of the volva, to the gleba, and to the gelatinous tissue of the chambers of the receptaculum. The elongation of the receptacle begins at the base and after its elongation, the gleba hangs suspended from the arch of the receptaculum by medullary tissue constituting the chamber masses of the receptacle.[12]

Like all Phallaceae species, C. columnatus is saprobic, and uses extracellular digestion to acquire nutrients from dead and decaying organic matter, like wood. As a consequence of its predilection for dead wood, the fungus is often associated with disturbed habitats. It can often be found growing in and around gardens and residences where areas of cultivation or landscaping have resulted in accumulations of mulch, wood chips or other cellulose-rich materials. The mycelial cords can be traced to buried roots, stumps, and other woody material.[3] The species grows in sandy soil,[12] near woody debris, in lawns, gardens, and cultivated soil.[11] Fruit bodies appear singly, or scattered, and can arise in the summer, autumn, and early winter, especially after wet weather.[13]

Like other member of the family Phallaceae, the mature fungus attracts insects with its smell to help disperse its spores. Psilopyga fasciata, a stinkhorn beetle of the sap beetle family, has been recorded feeding on the gleba of Mexican specimens.[15]

In 1980 Donald Malcolm Dring summarized the known geographical distribution of C. columnatus; the fungus has been collected in Australia, New Zealand, Oceania, New Guinea, Africa, and North and South America;[16] According to Australian mycologist Tom May, the Australian distribution is "presumably erroneous", as it is based on only a single collection in 1948.[17] In Central America, it has been collected from Costa Rica.[18] It is also found in China, in Jiangsu, Fujian, and Guangdong.[19] The North American distribution extends south to Mexico, and north to New York;[11] it is also in Hawaii.[9] The fungus is less common in the southeastern and southern United States.[13] It is thought to have been introduced to North America, as it typically appear in landscaped areas or other locations where exotic plants have been established.[20]