Geranium purpureum

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Geranium purpureum
Geranium purpureum 3.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Geraniales
Family: Geraniaceae
Genus: Geranium
Species:
G. purpureum
Binomial name
Geranium purpureum
Synonyms [2]
Homotypic synonyms
    • Geranium robertianum proles purpureum(Vill.) Rouy
    • Geranium robertianum subsp. purpureum(Vill.) Nyman
    • Geranium robertianum purpureum(Vill.) Pers.
    • Geranium robertianum var. purpureum(Vill.) DC.
    • Robertium purpureum(Vill.) Fourr.
    • Robertium vulgare var. purpureum(Vill.) Picard
Heterotypic synonyms
    • Geranium eginenseHausskn. & Sint. ex R.Knuth
    • Geranium mediterraneumJord.
    • Geranium minutiflorumJord.
    • Geranium modestumJord.
    • Geranium purpureum var. forsteriWilmott
    • Geranium purpureum subsp. forsteri(Wilmott) H.G.Baker
    • Geranium purpureum var. intricatum(Gren. ex Rouy) Graebn.
    • Geranium purpureum var. mediterraneum(Jord.) Graebn.
    • Geranium purpureum var. minutiflorum(Jord.) Loret & Barrandon
    • Geranium purpureum var. modestum(Fourr.) Hausskn.
    • Geranium purpureum var. modestum(Fourr.) Nyman
    • Geranium purpureum f. subeglandulosumH.Lindb.
    • Geranium robertianum var. incisumA.St.-Hil.
    • Geranium robertianum f. intricatum(Gren. ex Rouy) Merino
    • Geranium robertianum var. intricatumGren. ex Rouy
    • Geranium robertianum subvar. mediterraneum(Jord.) Litard.
    • Geranium robertianum var. mediterraneum(Jord.) Rouy
    • Geranium robertianum f. minutiflorum(Jord.) Merino
    • Geranium robertianum var. minutiflorum(Jord.) St.-Lag.
    • Geranium robertianum f. modestum(Fourr.) F.N.Williams
    • Geranium robertianum var. modestum(Fourr.) St.-Lag.
    • Geranium robertianum subvar. modestum(Fourr.) Litard.
    • Geranium robertianum var. parviflorumViv.
    • Geranium robertianum var. rubricauleHornem.
    • Geranium robertianum f. subeglandulosumH.Lindb.
    • Geranium robertianum var. villarsianum(Jord.) Rouy & Foucaud
    • Geranium semiglabrumJord. ex Boreau
    • Geranium simileJord. ex Nyman
    • Geranium villarsianumJord.
    • Robertium minutiflorum(Jord.) Fourr.
    • Robertium modestumFourr.
    • Robertium semiglabrum(Jord. ex Boreau) Fourr.
    • Robertium simileFourr.

Geranium purpureum, the little-robin, is a species of flowering plant in the geranium family Geraniaceae. It is native to Europe, Africa, and western Asia, and introduced on all continents except Antarctica. It is similar in appearance to Geranium robertianum , a close relative.

Contents

Description

Geranium purpureum is an annual (sometimes biennial), herbaceous, flowering plant. It has small flowers with 5  sepals and 5  petals, each petal being 6.3–8.4 mm long and 1.5–2.0 mm wide. The flower has 10  stamens, each with a yellow anther. In the center of the flower, a single fused style supports 5  stigmas. The fruit is a schizocarp, which splits into 5 one-seeded mericarps at maturity.

Identification

Flower with corolla approximately 7 mm in diameter Geranium purpureum sl10.jpg
Flower with corolla approximately 7 mm in diameter

Geranium purpureum is often confused with Geranium robertianum , a close relative. The primary character that distinguishes the two species is flower size. The corolla of Geranium purpureum is approximately 7.5 mm in diameter while that of Geranium robertianum is at least twice that size (15–20 mm). [3] (For comparison, a U.S. dime is approximately 18 mm in diameter.) An identification key for genus Geranium in California distinguishes the two species as follows: [4]

Other keys emphasize the hairs on the sepals as a distinguishing characteristic. [3] All keys include anther color but since both species have yellow pollen, plants can be difficult to distinguish based on anther color alone. Geranium purpureum and Geranium robertianum have chromosome numbers 2n = 32 and 2n = 64, respectively.

Taxonomy

Illustration of Geranium purpureum (lower righthand corner) published by Villars in 1789 Geranium argenteum-purpureum-rivale Dominique Villars 1789.jpg
Illustration of Geranium purpureum (lower righthand corner) published by Villars in 1789

Geranium purpureum was first described and named by the French botanist Domínique Villars in February 1786. [1] [7] A second description was published by Villars in June of the same year. [8] Taken together, he described a plant growing on the rocks with red leaves and a tiny reddish-pink corolla. In 1788, he further described the leaves as pinnately lobed with 5 segments. [9] Finally he published an illustration of Geranium purpureum in 1789. [10]

Geranium purpureumVill. is a member of Geranium section Ruberta in family Geraniaceae. [11] As of September 2025, the name Geranium purpureumVill. is widely accepted. [2] [12] Some authorities accept the name Geranium robertianum subsp. purpureum(Vill.) Nyman, [13] a homotypic synonym of Geranium purpureumVill. [14]

Distribution and habitat

Geranium purpureum growing along the tracks at the Wien Floridsdorf railway station in Vienna Geranium purpureum sl1.jpg
Geranium purpureum growing along the tracks at the Wien Floridsdorf railway station in Vienna

Geranium purpureum ranges from Great Britain southeastward to the Caucasus, with native populations occurring as far south as central Africa. [2] Non-native populations occur on all continents except Antarctica. Introduced populations are often found along railway corridors. [15] [16] [17]

Ecology

Geranium purpureum can not survive winters with an average January temperature of 4 °C (39 °F) or less. [18]

References

  1. 1 2 "Geranium purpureumVill.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 4 September 2025.
  2. 1 2 3 "Geranium purpureumVill.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 2 September 2025.
  3. 1 2 Kim et al. (2019), p. 210.
  4. Aedo, Carlos (2024). "Key page for Geranium". Jepson eFlora, Revision 13. University of California, Berkeley. Retrieved 4 September 2025.
  5. Aedo, Carlos (2024). "Geranium purpureum". Jepson eFlora, Revision 13. University of California, Berkeley. Retrieved 4 September 2025.
  6. Aedo, Carlos (2024). "Geranium robertianum". Jepson eFlora, Revision 13. University of California, Berkeley. Retrieved 6 September 2025.
  7. Villars (1786a), p. 272.
  8. Villars (1786b), pp. 72–73.
  9. Villars (1788), p. 374.
  10. Villars (1789), Plate XL.
  11. Aedo (2017).
  12. "Geranium purpureumVill.". World Flora Online. Retrieved 6 September 2025.
  13. NRCS (6 September 2025), "Geranium robertianum L. ssp. purpureum (Vill.) Nyman", PLANTS Database, United States Department of Agriculture (USDA)
  14. "Geranium robertianum subsp. purpureum(Vill.) Nyman". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 6 September 2025.
  15. "Little-Robin, Geranium purpureumVill.". Plant Atlas 2020. Botanical Society of Britain and Ireland. Retrieved 4 September 2025.
  16. Eliáš (2011).
  17. Kim et al. (2019).
  18. Kim et al. (2019), pp. 213–214.

Bibliography