Sherardia

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Sherardia arvensis
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Gentianales
Family: Rubiaceae
Subfamily: Rubioideae
Tribe: Rubieae
Genus: Sherardia
Species: S. arvensis
Binomial name
Sherardia arvensis
L.

Sherardia is a monotypic genus containing a single species, Sherardia arvensis (or Field Madder), which is a flowering plant in the Rubiaceae family. It is native to Europe, northern Africa and southwest Asia. Sherardia arvensis is closely related to the bedstraws (genus Galium). It is mainly noted as a weed but has sometimes found use as a dye plant.

Description

It is an annual plant with trailing and upright stems growing up to 40 cm long, having a square cross-section. The rough pointed bristly leaves of about 1 cm in length are in whorls of four to six (normally six at the ends of the shoots, but four nearer the root).

The tiny pale lilac or pink flowers are approximately 3mm in diameter and have a long tube, with only the end part of the four petals free. The flowers grow in "heads" of two or three together in an involucral structure formed out of a ring of six bracts.

The fruit are dry and about 3mm long with two lobes giving rise to the two seeds (nutlets).

The four-angled stems with whorls of bristly leaves and tiny flowers are reminiscent of the Bedstraws and other related Rubiaceae, but Sherardia is distinguished by its mauve/pink flowers which have a long tube, and which only in this case are in heads.[1][2]

Importance

This is a common weed of fields, pasture, grassland, and disturbed areas.[2] The roots can be used as a red dye but this plant is considered inferior to true Madder.[3]

Taxonomy

The species and genus were described by Linnaeus in Hortus Cliffortianus in 1736[4] and also appeared in his masterwork Species Plantarum in 1753.[5] The genus was named in memory of the prominent English botanist William Sherard (1659–1728).[6]

The Latin epithet arvensis means that it is found in fields. It is called Field Madder because of its resemblance to Madder (Rubia tinctorum), which is a better known dye plant of the same botanical tribe.

A supposed second species of the same genus, Sherardia orientalis Boiss. & Hohen., has been referred to, notably in ITIS,[7] but in fact this is a nomen nudum and it actually refers to Asperula orientalis Boiss. & Hohen..[8] This has now been corrected in ITIS.

  • Flowers

  • Groundcover

  • Illustration

References

  1. ↑ A. R. Clapham, T. G. Tutin, E. F. Warburg (1981). Excursion Flora of the British Isles (3rd ed.). Cambridge: Cambridge University Press. p. 299. 
  2. ↑ 2.0 2.1 IPM.ucdavis.edu
  3. ↑ See "Chest of Books" page
  4. ↑ C. Linnaeus (1737). Hortus Cliffortianus. Amsterdam: George Clifford. p. 33.  See also the George Clifford Herbarium. The relevant page is on-line at the German BioLib site. At the end of the Sherardia entry, Linnaeus mentions that the plant was named in memory of William Sherard.
  5. ↑ C. Linnaeus (1753). Species Plantarum ... p. 102.  The relevant page is on-line at the Biodiversity Heritage Library.
  6. ↑ (French) (Latin) Sébastien Vaillant, L'Établissement de trois nouveaux genres de plantes … Sherardia …, p. PA46, at Google Books, 1718
  7. ↑ ITIS.gov
  8. ↑ The USDA site is plants.usda.gov. See this mirror page of Hamburg university for the exclusion of S. orientalis.

External links

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