Subspecies purpureum is an upright annual in stony or rocky places near the sea, on sheltered cliffs, disused railway lines, and particularly by roads and fields on the earth-and-stone sides of Cornish hedge banks. Subsp. forsteri is a prostrate plant of stabilised areas at the top of shingle beaches. Lowland.
Since the 1962 Atlas, G. purpureum has been lost from some outlying areas, but in Cornwall it has increased markedly since about the mid-1970s, possibly benefiting from modern road verge management and recent mild winters.
Count of 10km squares in Great Britain: 52
Count of 10km squares in Ireland: 4
Count of 10km squares in the Channel Isles: 11
Atlas Change Index: 0.22
RDB Species Accounts
Geranium purpureum Villars (Geraniaceae)
Little robin, Llys Robert Bychan
Status in Britain: LOWER RISK – Nationally Scarce.
Status in Europe: Not threatened.
G. purpureum is a plant of warm, open places, occurring in two distinct natural habitats in Britain. In the first, it grows as an upright plant in rocky places, cliffs and dry hills and hedge banks, where it has as associates Centranthus ruber, Dactylis glomerata, Galium aparine, G. mollugo, Geranium robertianum, Hedera helix, Lonicera periclymenum and Rubus fruticosus. In the second it grows as a prostrate plant in stabilised areas at the rear of shingle beaches, in a very open community with Atriplex species, Geranium robertianum, Glaucium flavum, Lathyrus japonicus and Silene uniflora. Both habitats are usually near the sea, and often in a rich soil (Baker 1955).
G. purpureum is an annual, usually self-pollinated, which sets copious seed. Flowering is generally from June onwards, though plants may flower (and seed) much earlier in Cornwall at least.
The plant seems to be contracting in its British range with records since 1992 only from Cornwall, Devon, Somerset, Dorset and Hampshire. However, the Cornwall population has increased considerably within the last twenty years, possibly because it seems to respond well to modern road verge management, and perhaps also because of recent mild winters (FitzGerald 1990c). There are small populations in the Avon Gorge and Devon, but a few more records from Hampshire where it seems to be holding its own, in populations ranging from a few individuals to many hundreds of plants. The native status of the quite substantial Dorset site, which occurs along an old railway, is unclear. Here the plant is threatened by possible road development and by occasional spraying. G. purpureum was formerly recorded from Sussex, Gloucestershire and Carmarthenshire. It may be somewhat overlooked, as it is difficult, if not impossible, to tell from G. robertianum in a vegetative state.
The plant is widespread in southern and western Europe, reaching its most northerly point in southern Ireland, (where plants occur both on rocks and beaches), and spreading east through the Mediterranean and North Africa to Turkey and Iran. It is naturalised in New Zealand.
Throughout its range, G. purpureum is a variable plant, some authorities (e.g. Baker 1955) having distinguished two subspecies, ssp. purpureum and ssp. forsteri, on the basis of vague characters. Current opinion is very much divided on the desirability of recognising these two segregates. Ssp. forsteri is found on stabilised shingle at several locations in Hampshire (Brewis, et al. 1996), and formerly in Sussex, while all other British populations appear to be ssp. purpureum. There is also confusion between G. purpureum and maritime variants of G. robertianum, and it is likely that the former has been over-recorded in the past for that reason. In the field the combination of small flowers and yellow anthers separates G. purpureum, which also differs in chromosome number, but these differences are useless in herbarium specimens.
D. A. Pearman
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
Atlas Supp (17a
1955. Geranium purpureum Vill. and G. robertianum L. in the British Flora: I. Geranium purpureum. Watsonia. 3:160-167.
1988. The Irish Red Data Book. 1. Vascular Plants.
1990. Rare Plant Survey of South-West England. Vol. 3. Cornwall. CSD Report, no. 1060.
1999. Flora of Cornwall.
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
1978. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols.
1999. British Red Data Books. 1. Vascular plants, edn 3.