''Paris quadrifolia'', the herb Paris or true lover's knot, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Melanthiaceae Melanthiaceae, also called the bunchflower family, is a family of flowering herbaceous perennial plants native to the Northern Hemisphere. Along with many other lilioid monocots, early authors considered members of this family to belong to t ...

. It occurs in temperate and cool areas throughout

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelag ...

, from

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

Yakutia Sakha, officially the Republic of Sakha (Yakutia),, is the largest republic of Russia, located in the Russian Far East, along the Arctic Ocean, with a population of roughly 1 million. Sakha comprises half of the area of its governing Far E ...

, and from

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...

. It prefers

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...

soils and lives in damp and shady places, especially old established woods and stream banks. ''P. quadrifolia'' is in decline in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

due to

loss of habitat Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. In Iceland, for example, it is on the red list.

Characteristics

''P. quadrifolia'' is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widel ...

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition ...

that is tall. It may have 3–8 leaves but typically there are four leaves arranged as opposing pairs. The flowers are wispy and inconspicuous. The plant flowers during the months of June and July. It has a solitary flower with four narrow greenish filiform (threadlike) petals, four green petaloid sepals, eight golden yellow stamens, and a round purple to red ovary. The flower is borne above a single

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

of four leaves. Each plant produces at most one blueberry-like

berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, rasp ...

, which is poisonous, as are other plant tissues. Poisonings are rare because the plant's solitary berry has a repulsive taste that makes it difficult to mistake for a

bilberry Bilberries (), or sometimes European blueberries, are a primarily Eurasian species of low-growing shrubs in the genus '' Vaccinium'' (family Ericaceae), bearing edible, dark blue berries. The species most often referred to is ''Vaccinium myrti ...

Gallery

File:20170922-paris quadrifolia-einbeere.jpg, File:Little Sorn burnside.JPG, File:Paris quadrifolia fruit - Keila.jpg, File:Paris quadrifolia.JPG, File:Little Sorn and Cessnock Water.JPG,

References

External links

HoloGuides - photos
Melanthiaceae Flora of Europe Flora of Asia Plants described in 1753 Taxa named by Carl Linnaeus {{liliales-stub