Paris quadrifolia

This article is about the plant species Paris quadrifolia. For other uses, see Paris (disambiguation).

Paris quadrifolia, the herb Paris^[4] or true lover's knot, is a species of flowering plant in the family Melanthiaceae. It occurs in temperate and cool areas throughout Eurasia, from Spain to Yakutia, and from Iceland to Mongolia.^[2] It prefers calcareous soils and lives in damp and shady places, especially old established woods and stream banks.

Paris quadrifolia
Paris quadrifolia in Ciemnik, Poland
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Liliales
Family:	Melanthiaceae
Genus:	Paris
Species:	P. quadrifolia
Binomial name
Paris quadrifolia L.
Synonyms[2]
Paris pentafolia P.Renault Paris trifolia P.Renault Paris quadrifolia var. angustiovata D.Z.Ma & H.L.Liu

1885 illustration^[3]

Flower

P. quadrifolia is in decline in Europe due to loss of habitat.^[5] In Iceland, for example, it is on the red list.^[6]

Description

P. quadrifolia is a perennial herbaceous plant that is 25 to 40 cm (10 to 15.5 in) tall. It may have 3–8 leaves but typically there are four leaves arranged as opposing pairs. The flowers are wispy and inconspicuous.^[5][7]

The plant flowers during the months of June and July.^[8] 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 of four leaves.

Each plant produces at most one blueberry-like berry, , which persists for an average of 46.2 days, and bears an average of 33.6 seeds per fruit. Fruits average 89.6% water, and their dry weight includes 14.5% carbohydrates and 2.6% lipids.^[9] The berry is poisonous, because it contains solanine, as are other plant tissues.^[10] Poisonings are rare because the plant's solitary berry has a repulsive taste that makes it difficult to mistake for a bilberry.

Raphides occur in at least the perianth,^[11] the stem, the smaller cells of the rhizome, and in abundance in the root.^[12] Its raphis-cells are elongated, pointed at the ends, and much longer than the contained raphides.^[11]

Taxonomy

It was described by Carl Linnaeus in 1753.^[13][5]

Ecology

In some patches studied by Ehrlén and Eriksson 1993, Clethrionomys glareolus and Apodemus sp. removed up to 80% of the fruits. They are graniviorous, consuming most of the seeds but only a small proportion of the fruit's pulp. As some seeds inevitably escape predation, they also act as seed dispersers.^[14]

Etymology

The specific epithet quadrifolia means four-leaved.^[15]

Conservation

It is categorised as a species of Least Concern (LC) according to the IUCN red list.^[1]

Gallery

• 
  Herb Paris with Fruit
• 
  Typical Herb Paris woodland habitat in Ayrshire, Scotland.
• 
  Fruit
• 
  Details of the leaves.
• 
  Typical limestone (cornstone) based woodlands rich in Herb Paris colonies.