A rust on leaves, petioles and stems of Circuta virosa (cowbane), visible as yellow-orange (aecidia), cinnamon (uredosori) or brown-black (teliosori) pustules on leaves and stems.
Spermogonia on both sides of leaves, between the aecidia, rounded, almost colourless, subepidermal, 100-125 µm diam., with projecting paraphyses. Aecidia on all sides of leaves, petioles and stems, on yellowish spots which become darker, in rounded ellipsoidal or elongated groups, up to 1.5 cm long, pustular, peridium cupulate or hemispherical, with entire margin, rather short, golden-yellow; aecidiospores globoid to ellipsoid, 17-26 x 10-20 µm, wall finely puctate, subhyaline. Uredosori generally on leaf undersides, scattered, minute, pulverulent, cinnamon; uredospores subgloboid to ovoid, yellow-brown, 18-28 x 14-22 µm, wall echinulate, with 3 equatorial pores. Teliosori similar, but blackish-brown; teliospores ellipsoid, or oblong, rounded at both ends or rarely attenuated downwards, not thickened above, generally constricted, wall 28-46 x 18-30 µm, wall somewhat verruculose or distinctly verrucose-reticulated, occasionally nearly smooth, brown, pore of upper cell apical, of lower cell subequatorial, pedicels hyaline, thin, short, falling off when mature. Auteu-form (all life stages associated with one host plant), aecidia developing in June, and uredospores and teliospores developing from July-October
Description adapted from Wilson, M., & Henderson, D. M. (1966). British rust fungi.
Not formally assessed. Considered extinct (EX 1956) in Great Britain and the Isle of Man, in the current but unofficial Red Data List of Threatened British Fungi (Evans et al., 2006). However, recent finds in 2011 and 2012 have indicated that this species is extant in at least two sites in East Norfolk and East Suffolk.
None known on this host.
Puccinia cicutae is an obligate biotrophic parasite and pathogen of Cicuta virosa (cowbane), and is only associated with this host plant.
In Great Britain, historically known only from seven sites throughout the Fens in Norfolk and Suffolk, England. Currently known only from two sites: Barnby Broad Estate, East Suffolk VC25, and Woodbastwick Fen NNR, East Norfolk VC27.
The host, Cicuta virosa, is considered Nationally Scarce (present in fewer than 100 hectads) in Britain, but stable as of 2002, with its main centres of population in central Ireland and the Shropshire-Cheshire plain, and patchily distributed elsewhere (see: Lockton, A.J. [08/03/2016]. Species account: Cicuta virosa. Botanical Society of the British Isles. www.bsbi.org.uk., at: http://sppaccounts.bsbi.org.uk/content/cicuta-virosa-0).