Calystegia pulchra Brummitt & Heywood, Hairy Bindweed
Account Summary
Introduction, neophyte, a very rare garden escape.
17 September 1993; Northridge, R.H.; grounds of Portora Royal School, Enniskillen.
July to September.
This large pink-flowered garden species of bindweed has only been found in three widely spaced sites in Fermanagh. The details of the other two records are: near houses, Clabby Village, 21 June 1997, I. McNeill; on waste ground between road and lake in front of house at Bleanalung Bay, NE Lower Lough Erne, 4 October 2010, RHN & HJN.
C. pulchra is a hairy stemmed climbing perennial of unknown geographical origin. It may either have been introduced directly from NE Asia, or perhaps it may have arisen as a hybrid during European garden cultivation (Griffiths 1994). It is rather similar to C. sepium subsp. roseata, both bindweeds having either pure pink or pink and white striped flowers and short hairs on their stems, leaf-stalks and flower-stalks. The principal difference between them is the form of the bracteoles, which in C. pulchra are strongly inflated, pouch-like and overlapping one another, whilst those of C. sepium subsp. roseata are about as long as the calyx, not inflated and scarcely overlap at all (An Irish Flora 1996).
C. pulchra was probably first introduced to B & I around the 1850s or 1860s, since the first European herbarium specimens known are both dated 1867 (one from Twickenham Park (VC 21) and one from Sweden) (Brummitt & Heywood 1960). C. pulchra very frequently escapes from gardens and it has become naturalised locally. Nowadays, it is widely scattered throughout the whole of these islands and very probably it is still spreading (Clement & Foster 1994; G.M. Kay, in: Preston et al. 2002). It is also naturalised in Holland, France, Germany, Poland, Austria, Czechoslavia, Denmark and Sweden, and possibly elsewhere in Europe (Perring & Sell 1968). In Britain it appears to be most frequent in SE and NW England, and in the Glasgow and Edinburgh regions of Scotland, usually occurring close to habitation (Garrard & Streeter 1983; G.M. Kay, in: Preston et al. 2002).
The Cen Cat Fl Ir 2 indicates C. pulchra has been recorded from 25 of the 40 Irish VCs, and Cat Alien Pl Ir listed seven additional VCs, which brings the total to 32. Inspection of the New Atlas hectad map suggests that C. pulchra is more frequent and widespread in NI than is the case in the RoI.
Threats
The species does not set much or any seed, but it is actively spreading, probably as rhizome fragments transported with soil. It could easily become a nuisance over time, having the ability to overgrow native vegetation.