GERANIUM PURPUREUM VILL. AND G. ROBERTIANUM L, : II 273 



It is necessary to explain why Hornemann's varietal name has not been used in 

 constructing the subspecific epithet. It has already been rejected by Wilmott (1921) on 

 the grounds that it is impossible to refer this name to any shingle form in particular. 

 Although, with the more widely cast boundaries of the subspecies used here, this objection 

 no longer applies, it is true that from Hornemann's original description it is not certain 

 that he had only shingle-beach plants in mind and, indeed, most subsequent authors have 

 used the name ruhricaule for any conspicuously reddened plants irrespective of their 

 habitat. Unfortunately Hornemann left no herbarium specimen which could serve as 

 a type. 



There is no ambiguity, however, concerning Babington's appropriately named 

 variety maritimum. Contrary to Wilmott's (1921) suggestion, there is no evidence that 

 Babington intended to restrict his seashore variety to the almost completely glabrous 

 plant found at Shoreham. In any case, the Shoreham plant merely represents the extreme 

 form in a long series (or cline) in which the hairiness increases (through Wilmott's var. 

 intermedium) to the extremely hirsute plants which grow on the Chesil Beach, on such 

 islands as Steep Holm and Flat Holm and on the cliffs at Berry Head in South Devon 

 (var. hispidum of Druce). Therefore it seems justifiable to raise Babington's variety to 

 the status of a subspecies and to include within it all the inherently prostrate maritime 

 plants. 



One character of these maritime plants to which Wilmott (1921) has drawn particular 

 attention is their prevailingly glabrous fruits. This is certainly a useful adjunct to the 

 identification of fragmentary and ill-labelled herbarium material in which the habit of 

 the original plant is often indistinguishable, but it is incorrect to assume, as does Wilmott, 

 that material of this subspecies may never have hairy fruits. Thus his exclusion of some 

 of the plants which grow on the shingle at Kingsdown (East Kent), for this reason, is 

 unnatural, especially as the cultivation of similar material from Three Cliffs Bay (Glam.) 

 has shown that its behaviour and habit are exactly the same as in glabrous-fruited maritime 

 plants. 



This, then, is the " var. purpureum " of most authors of local floras and it is largely 

 to them that the confusion between this subspecies and G. purpureum itself has been 

 due (vide Baker, 1955). The characters which distinguish the subspecies from typical 

 G. robertianum are often not well preserved in herbarium material and, in critical cases, 

 cultivation from seed may be necessary for certainty in determination. Nevertheless 

 there are strong physiological and ecological differences and some distinctive morphological 

 features, so that subspecific recognition is quite justified. 



Very few plants of subsp. maritimum flower in their first season, during which they 

 normally produce a prostrate, open rosette in which all petioles are much of the same 

 length. The leaves have characteristically narrower leaflet-segments and shorter petioles 

 than those of subsp. robertianum. There is a tendency for plants to rot at the crown 

 in moist garden soil and the rosette-leaves decay more easily than those of the type 

 subspecies. In cultivation subsp. maritimum tends to flower rather later and, in the 

 flowering condition, the stems lie prostrate or ascend arcuately from the crown. The 

 flowers are slightly smaller than those of subsp. robertianum (usually 1-3-1-4 cm. in 

 diameter) and the fruits are usually nearly or completely glabrous. 



It is found on stable shingle, particularly at the rear of fringing beaches, around the 

 coasts of the British Isles and, less frequently, on cliffs and seaside walls. It is unlikely 

 that a real climatic preference is to be seen in the greater frequency of this subspecies 

 in south-eastern England, where its abundance is surely related to the large number of 

 suitable beaches. Bocher (1947) has pointed out that, in its European distribution, this 

 subspecies may reach from Madeira to Norway and the Baltic, although there are many 



