Arum maculatum L., Sp. Pl. 966 1753. (syn: Arisarum maculatum (L.) Raf.; Arum alpinum subsp. pyrenaeum (Dufour) Nyman; Arum gracile Unverr. ex Schott; Arum heldreichii Orph. ex Boiss.; Arum immaculatum (Rchb.) Rchb.; Arum italicum var. amoenum Engl.; Arum maculatum var. flavescens Melzer ex Janch. [Invalid] ……………..; Arum malyi Schott; Arum orientale subsp. amoenum (Engl.) R.R.Mill; Arum pyrenaeum Dufour; Arum trapezuntinum Schott ex Engl.; Arum vernale Salisb.; Arum vulgare Lam.; Arum zelebori Schott) ?;
Arum maculatum is a common woodland plant species of the Araceae family. It is widespread across most of Europe, as well as Turkey and the Caucasus. It is known by an abundance of common names including snakeshead, adder’s root, arum, wild arum, arum lily, lords-and-ladies, devils and angels, cows and bulls, cuckoo-pint, Adam and Eve, bobbins, naked girls, naked boys, starch-root, wake robin, friar’s cowl, and jack in the pulpit. The name “lords-and-ladies” and other gender-related names refer to the plant’s likeness to male and female genitalia symbolising copulation. 
The purple-spotted leaves of A. maculatum appear in the spring (April–May) followed by the flowers borne on a poker-shaped inflorescence called a spadix, which is is partially enclosed in a pale green spathe or leaf-like hood. The flowers are hidden from sight, clustered at the base of the spadix with a ring of female flowers at the bottom and a ring of male flowers above them.
Above the male flowers is a ring of hairs forming an insect trap. Insects, especially owl-midges Psychoda phalaenoides, are attracted to the spadix by its faecal odour and a temperature up to 15°C warmer than the ambient temperature. The insects are trapped beneath the ring of hairs and are dusted with pollen by the male flowers before escaping and carrying the pollen to the spadices of other plants, where they pollinate the female flowers. The spadix may also be yellow, but purple is the more common.
In autumn, the lower ring of (female) flowers forms a cluster of bright red berries which remain after the spathe and other leaves have withered away. These attractive red to orange berries are extremely poisonous. The berries contain oxalates of saponins which have needle-shaped crystals which irritate the skin, mouth, tongue, and throat, and result in swelling of throat, difficulty breathing, burning pain, and upset stomach. However, their acrid taste, coupled with the almost immediate tingling sensation in the mouth when consumed, means that large amounts are rarely taken and serious harm is unusual. It is one of the most common causes of accidental plant poisoning based on attendance at hospital emergency departments.
The root-tuber may be very big and is used to store starch. In mature specimens, the tuber may be as much as 400 mm below ground level.
All parts of the plant can produce allergic reactions in many people and the plant should be handled with care. Many small rodents appear to find the spadix particularly attractive; finding examples of the plant with much of the spadix eaten away is common. The spadix produces heat and probably scent as the flowers mature, and this may attract the rodents.
(from Wikipedia on 25.10.16)
Plant for ID: EU-ARKOCT15 : 8 posts by 3 authors. Attachments (4)
This was growing on the wet forest floor near Rhine falls near Zurich, Switzerland. There was no opened flower.
Requested to please provide ID.
Looks like Arum maculatum (Lords and Ladies/ Cuckoo Pint) see http://eol.org/pages/1133264/media
It is probably Arum maculatum – the species commonly has plain green leaves despite the name.
Seems to be Arum italicum but without an open flower very difficult to be 100% certain.
Only two sp. Arum cylindraceum Gasp. and Arum italicum Mill. , have got distribution in Switzerland and Arum cylindraceum Gasp. looks more close.