A very odd little aroid, Arisarum proboscideum , has an appendix that mimics the appearance of a fungus. While several arisaemas are pollinated by fungus gnats and invite their visitors by giving out mushroomy smells, none are known to go to this extreme. Commonly known as the mouse plant, A. proboscideum is popular in cultivation for its spathes, which have brown tails about 7 in. long that protrude above the dense mass of glossy sagitate leaves, looking as if a family of mice has just dived for cover. The species is found wild in woods in Italy and Spain, but not in Albania as stated in Cecil Prime's Lords and Ladies . The confusion probably arose from a collection in the herbarium at the Royal Botanic Gardens, Kew; made in 1867 and labelled In montibus Albanis , the specimen came from the Alban hills southeast of Rome. The inflorescences are on pale stalks about 6 in.

tall and are held slightly inclined towards the ground. The lower portion of the spathe forms a tube 2-3 in. long with a slightly velvety brown hood and a white base. The only opening is a small hole beneath the point where the hood marrows into the elongated curve of the tail. To appreciate this inflorescence fully, it is necessary to cut away one side. Inside is the crooked spadix with a few female flowers at the base and a larger number of male flowers above. Then, fitting exactly into the hood of the spathe, is the whites spongy appendix, a perfect replica of the underside of a fungus. Its faint mushroomy scent attracts female fungus gnats.

Once inside the inflorescence the insects are stimulated to lay their eggs by the appearance and humidity of the imitation fungus. The eggs are deposited in the cavities of the spongy tissies, and the larvae subsequently hatch, only to starve on the fake food. After egg-laying, the gnats enter the spathe chamber by either falling into it or being guided downwards by the bright refractive base. As they struggle to escape they drop any pollen they may be carrying from a previously visited inflorescence and pick up a new load before they leave. The flowering of this cunning little aroid is timed to coincide with the first springtime generation of gnats. The insects are compelled to breed when few real fungi can be found, so that their desperate search for somewhere to lay their eggs they are readily taken in by this aroid's enticing guise. Such behaviour has earned the inflorescences the description of "parasites on the ecosystem" (Vogel 1973). This strange case of mimicry was first described in 1891 by an Italian botanist who referred to Arisum proboscideum as "the most peculiar herb in Europe" (Arcangeli 1891).