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Hunting rare rusts in NW Wales
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Hunting rare rusts in NW Wales 2 ;FOE @ FO O M 1 MO JLLO DLF L)O = O D K G
7H 8 L M OO LO
he rusts are an amazing group of fungi infecting a wide range of higher plants. They are obligate parasites, incapable of a free-living existence and are dependent on their hosts. A single species can produce up to five different types of spores, each produced in a different structure and some species have to alternate between two taxonomically unrelated hosts to complete their complex life cycles. Dr Richard Shattock first introduced me to the rusts in 2002 while I was working on Phytophthora infestans at Bangor University. Richard was particularly interested at this time in microcyclic rusts; rust species which have evolved much shorter life cycles, no longer producing all the spore types and infecting only one host, (Quilliam & Shattock, 2003; Shattock, 2004). He showed me some ground elder, Aegopodium podagraria, infected with the black telia of Puccinia aegopodii (Fig. 1) that he had collected from near Llangollen and encouraged me to look out for it. I decided to go and investigate a nearby verge with ground elder and after some searching found a few infected leaves - the first record for Caernarfonshire, (VC49). This was easy! At the same time Nigel Stringer was requesting Welsh rust records and I determined to record as many species as I could. We are lucky in this area to have a huge variety of habitats ranging from coastal to mountain so the potential for host-rust associations is enormous. This was the beginning of my love affair/obsession with the rusts and by looking much more closely at both wild and cultivated plants I was soon generating lots of records. What do we mean by a ‘rare fungus’? The rarity, or perceived rarity status of a rust fungus can have several different explanations. A rust can be rare because its host plant is rare, or rare even though the host plant is very common. One host population may be especially susceptible while others are disease free, or just a few individuals within a huge stand of plants may be
infected. Where a rust species infects a range of hosts it may be common on one host and uncommon on another or even restricted to a single variety of the host. A rust may have a geographical rarity, being common in one area of the country while absent or uncommon in other areas. Recorder interest is a huge factor and I have proved this with my own efforts in NW Wales which have resulted in many new VC records. Finally recorder determination or sheer tenacity, a sharp eye for a sick plant or just a pale spot, plus a large element of luck also play a big part in finding the more uncommon species. I hope to illustrate these differences with some of my more notable records in this and future articles. Puccinia aegopodii should be a common rust with the amount of ground elder growing yet I have only found it at three further sites in Caernarfonshire and one on Anglesey despite careful searching of host populations and it must therefore be classed as locally uncommon but not rare in GB. At the first site only a few leaves were infected and required close inspection to locate while at other sites most of the plants were infected and the galled leaves were very obvious. This illustrates the variability of susceptibility of a host or pathogenicity of a rust. My first notable find of a genuinely rare rust was another microcyclic species, Puccinia fergussonii (Fig. 2) on marsh violet, Viola palustris, a fairly common plant of damp areas in Snowdonia. This was only the second record for VC49, the previous one being in 1941 and there are 22 records from 21 sites in the FRDBI. Richard’s reaction when I showed it to him was a delight! I now know of several sites in Snowdonia where this rust occurs but it is still quite a rare finding. Puccinia nemoralis (Fig. 3) is a very rare, heteroecious rust, (one alternating between two host plants), infecting common cow-wheat, Melampyrum pratense and purple moor-grass, Molinia caerulea. Bruce Ing first recorded it in
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doi:10.1016/j.fldmyc.2014.03.011
41
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J % && )! ( O O 666 O F N (' ' ) K :L J O O C N ?M 2MLN A ON IA>3 2 ;FO
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I K GH Britain in 1975 (Ing, 1978) and I was lucky enough to find it at a new site in Caernarfonshire on Melampyrum in 2005, and on the Molinia there in 2007. The white aecial cups readily distinguish this rust from the orange uredinia of Coleosporium tussilaginis which can also infect Melampyrum and many other plants. P. nemoralis is probably rare because the two host species do not commonly occur together; it is very rare in GB and is listed as vulnerable in the Red Data List of threatened British fungi. Wild primroses, Primula vulgaris are common flowers of hedgerows and woodland, but the rust that infects the plant appears to be quite rare especially in Wales. Up to 2004 there was only one known site locally for Puccinia primulae (Fig.4), a shady roadside bank on Anglesey, VC52, (Aron, 2005). I have since found infected primroses on a second Anglesey bank and on coastal grass near Holyhead and Trearddur Bay, plus just a few infected plants at a woodland site in Caernarfonshire, only a mile from my home. This was the first county record and the rust remains locally rare. The most pleasing discovery however, was finding P. primulae infecting cowslips, Primula veris, at Penrhos Nature Reserve, near Holyhead in 2006. There are only two confirmed records on this host in the FRDBI, both from the same site. I have always tried to look near to home for rusts before venturing further afield and this was especially successful with wood anemone, Anemone nemorosa. I wanted to find Tranzschelia anemones, a microcyclic rust I’d not seen, with only a single recent VC49 record. I searched a tiny patch of wood anemone within 100m of my house and I found the rust fairly easily but to my delight I also found Ochropsora ariae (Fig. 5), a second rust infecting the same host; easily differentiated by the white aecial cups instead of the dark-brown telia of T. anemones. I have now recorded T. anemones at many sites in both VCs 49 and 52, although it is never common here and I usually have to meticulously search huge stands before finding a few infected plants. In contrast O. ariae is much rarer both locally and in Wales; I have only found one site on Anglesey and I have a second record from Caernarfonshire. In 2007 I targeted rust species from my ‘wish list’ and went in search of Puccinia hydrocotyles (Fig. 6) and Chrysomyxa pirolata. Both species
had been recorded once previously on Anglesey but not in recent years. I spent a day scanning hundreds of leaves of marsh pennywort, Hydrocotyle vulgaris, in the dune slacks at Newborough Warren on Anglesey and was rewarded by finding a few leaves infected with P. hydrocotyles. The host is a very common plant of damp, marshy, boggy areas and dune slacks yet the rust is truly rare and is on the Red Data List as critically endangered, so it was very exciting to find it still occurring on this site. I failed to find the Chrysomyxa infecting the round-leaved wintergreen, Pyrola rotundifolia ssp. maritima, but I was more than compensated by also collecting Puccinia angelicae (Fig. 7) on wild angelica, Angelica sylvestris. I had been looking for this rust for several years without success. There is a single 1924 record from VC49 and only two other records for Wales despite the widespread occurrence of wild angelica so the rust must be quite rare or very uncommon, at least in Wales. I now have just one further record from Anglesey. There are many more rare or uncommon rusts occurring in this area but an exciting find in 2007 was recording Puccinia oxyriae. I was on a BSBI field trip on the slopes of Snowdon recording mountain plants. I found a single spot of the rust on a single leaf of mountain sorrel, Oxyria digyna (Fig. 8), yet this was enough to get me very excited much to the amusement of my companions. The rust had not been recorded in Wales since the only record in 1941. The rust was in the Red Data List as extinct as there were thought to be no recent records but it is now known to occur on the Scottish mountains, (pers. comm. A. Henrici). It poses a question “is the rust genuinely very rare?” The plant only occurs at higher altitudes but is not itself rare especially in Scotland and Snowdonia; however the number of rust recorders is low and the rarity may be of recorders who also climb mountains rather than the rust. I hoped to answer the question by targeting Oxyria in Snowdonia and to date I have not found any further records, suggesting it is genuinely uncommon/rare here. Rust recording is an exciting and rewarding passtime with the possibility of finding new VC records both for the individual rust species and for rusts occurring on new hosts. It additionally fills the gap in the spring and summer outside the main fungal season and can be thoroughly recommended!
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I K GH J 5 % && !'& O O 66 FO M M N !'& "' ) 7 June 2007, = L 8N @ON IAK 2 ;FO
J 7 % && (") O O 66N L O N ") !" :L
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References
Further Reading
Aron, C. (2005). Fungi of Northwest Wales. Self-published. Evans, S. (2007). The Red Data List of Threatened British Fungi. Ing, B. (1978). Puccinia nemoralis – a new British rust. Trans. Brit. Mycol. Soc. 71: 325–329. Quilliam, R.S. & Shattock, R.C. (2003). Haustoria of microcyclic rust fungi Uromyces ficariae and Puccinia tumida and other gall-forming species, U. dactylidis (macrocyclic), and P. smyrnii (demicyclic). Plant Pathology, 52: 104-113. Shattock, R. (2004). Microcyclic Rusts, M-Haustoria and…..Mycophyllas? Field Mycology, 5(4): 132-136.
Ellis, M.B, & Ellis, J.P. (1997). Microfungi on Land Plants - An Identification Handbook. Richmond Publishing. Henderson, D.M. (2000). A Checklist of the Rust Fungi of the British Isles. British Mycological Society. Henderson, D.M. (2004). The Rust Fungi of the British Isles - A Guide to Identification by their Host Plants. British Mycological Society. Termorshuizen, A.J. & Swertz, C.A. (2011). Roesten: Roesten van Nederland (Dutch Rust Fungi). Wilson, M. & Henderson, D.M. (1966). British Rust Fungi. Cambridge University Press.
2,
Hunting rare rusts in NW Wales 2 ;FOE @ FO O M 1 MO JLLO DLF L)O = O D K G
7H 8 L M OO LO
he rusts are an amazing group of fungi infecting a wide range of higher plants. They are obligate parasites, incapable of a free-living existence and are dependent on their hosts. A single species can produce up to five different types of spores, each produced in a different structure and some species have to alternate between two taxonomically unrelated hosts to complete their complex life cycles. Dr Richard Shattock first introduced me to the rusts in 2002 while I was working on Phytophthora infestans at Bangor University. Richard was particularly interested at this time in microcyclic rusts; rust species which have evolved much shorter life cycles, no longer producing all the spore types and infecting only one host, (Quilliam & Shattock, 2003; Shattock, 2004). He showed me some ground elder, Aegopodium podagraria, infected with the black telia of Puccinia aegopodii (Fig. 1) that he had collected from near Llangollen and encouraged me to look out for it. I decided to go and investigate a nearby verge with ground elder and after some searching found a few infected leaves - the first record for Caernarfonshire, (VC49). This was easy! At the same time Nigel Stringer was requesting Welsh rust records and I determined to record as many species as I could. We are lucky in this area to have a huge variety of habitats ranging from coastal to mountain so the potential for host-rust associations is enormous. This was the beginning of my love affair/obsession with the rusts and by looking much more closely at both wild and cultivated plants I was soon generating lots of records. What do we mean by a ‘rare fungus’? The rarity, or perceived rarity status of a rust fungus can have several different explanations. A rust can be rare because its host plant is rare, or rare even though the host plant is very common. One host population may be especially susceptible while others are disease free, or just a few individuals within a huge stand of plants may be
infected. Where a rust species infects a range of hosts it may be common on one host and uncommon on another or even restricted to a single variety of the host. A rust may have a geographical rarity, being common in one area of the country while absent or uncommon in other areas. Recorder interest is a huge factor and I have proved this with my own efforts in NW Wales which have resulted in many new VC records. Finally recorder determination or sheer tenacity, a sharp eye for a sick plant or just a pale spot, plus a large element of luck also play a big part in finding the more uncommon species. I hope to illustrate these differences with some of my more notable records in this and future articles. Puccinia aegopodii should be a common rust with the amount of ground elder growing yet I have only found it at three further sites in Caernarfonshire and one on Anglesey despite careful searching of host populations and it must therefore be classed as locally uncommon but not rare in GB. At the first site only a few leaves were infected and required close inspection to locate while at other sites most of the plants were infected and the galled leaves were very obvious. This illustrates the variability of susceptibility of a host or pathogenicity of a rust. My first notable find of a genuinely rare rust was another microcyclic species, Puccinia fergussonii (Fig. 2) on marsh violet, Viola palustris, a fairly common plant of damp areas in Snowdonia. This was only the second record for VC49, the previous one being in 1941 and there are 22 records from 21 sites in the FRDBI. Richard’s reaction when I showed it to him was a delight! I now know of several sites in Snowdonia where this rust occurs but it is still quite a rare finding. Puccinia nemoralis (Fig. 3) is a very rare, heteroecious rust, (one alternating between two host plants), infecting common cow-wheat, Melampyrum pratense and purple moor-grass, Molinia caerulea. Bruce Ing first recorded it in
T
E? 1 LON - JN MMN 00K4 >?"
doi:10.1016/j.fldmyc.2014.03.011
41
I K GH J % && !((N O O 666 LM MN !(( # ( !) ) < C
> MOM FN O LN A ON IA>3 2 ;FO
J % && )! ( O O 666 O F N (' ' ) K :L J O O C N ?M 2MLN A ON IA>3 2 ;FO
J < % && #() ' O O / / N ' #") # ) :L
KN MM OMN A ON IA>3 2 ;FO
4)
I K GH Britain in 1975 (Ing, 1978) and I was lucky enough to find it at a new site in Caernarfonshire on Melampyrum in 2005, and on the Molinia there in 2007. The white aecial cups readily distinguish this rust from the orange uredinia of Coleosporium tussilaginis which can also infect Melampyrum and many other plants. P. nemoralis is probably rare because the two host species do not commonly occur together; it is very rare in GB and is listed as vulnerable in the Red Data List of threatened British fungi. Wild primroses, Primula vulgaris are common flowers of hedgerows and woodland, but the rust that infects the plant appears to be quite rare especially in Wales. Up to 2004 there was only one known site locally for Puccinia primulae (Fig.4), a shady roadside bank on Anglesey, VC52, (Aron, 2005). I have since found infected primroses on a second Anglesey bank and on coastal grass near Holyhead and Trearddur Bay, plus just a few infected plants at a woodland site in Caernarfonshire, only a mile from my home. This was the first county record and the rust remains locally rare. The most pleasing discovery however, was finding P. primulae infecting cowslips, Primula veris, at Penrhos Nature Reserve, near Holyhead in 2006. There are only two confirmed records on this host in the FRDBI, both from the same site. I have always tried to look near to home for rusts before venturing further afield and this was especially successful with wood anemone, Anemone nemorosa. I wanted to find Tranzschelia anemones, a microcyclic rust I’d not seen, with only a single recent VC49 record. I searched a tiny patch of wood anemone within 100m of my house and I found the rust fairly easily but to my delight I also found Ochropsora ariae (Fig. 5), a second rust infecting the same host; easily differentiated by the white aecial cups instead of the dark-brown telia of T. anemones. I have now recorded T. anemones at many sites in both VCs 49 and 52, although it is never common here and I usually have to meticulously search huge stands before finding a few infected plants. In contrast O. ariae is much rarer both locally and in Wales; I have only found one site on Anglesey and I have a second record from Caernarfonshire. In 2007 I targeted rust species from my ‘wish list’ and went in search of Puccinia hydrocotyles (Fig. 6) and Chrysomyxa pirolata. Both species
had been recorded once previously on Anglesey but not in recent years. I spent a day scanning hundreds of leaves of marsh pennywort, Hydrocotyle vulgaris, in the dune slacks at Newborough Warren on Anglesey and was rewarded by finding a few leaves infected with P. hydrocotyles. The host is a very common plant of damp, marshy, boggy areas and dune slacks yet the rust is truly rare and is on the Red Data List as critically endangered, so it was very exciting to find it still occurring on this site. I failed to find the Chrysomyxa infecting the round-leaved wintergreen, Pyrola rotundifolia ssp. maritima, but I was more than compensated by also collecting Puccinia angelicae (Fig. 7) on wild angelica, Angelica sylvestris. I had been looking for this rust for several years without success. There is a single 1924 record from VC49 and only two other records for Wales despite the widespread occurrence of wild angelica so the rust must be quite rare or very uncommon, at least in Wales. I now have just one further record from Anglesey. There are many more rare or uncommon rusts occurring in this area but an exciting find in 2007 was recording Puccinia oxyriae. I was on a BSBI field trip on the slopes of Snowdon recording mountain plants. I found a single spot of the rust on a single leaf of mountain sorrel, Oxyria digyna (Fig. 8), yet this was enough to get me very excited much to the amusement of my companions. The rust had not been recorded in Wales since the only record in 1941. The rust was in the Red Data List as extinct as there were thought to be no recent records but it is now known to occur on the Scottish mountains, (pers. comm. A. Henrici). It poses a question “is the rust genuinely very rare?” The plant only occurs at higher altitudes but is not itself rare especially in Scotland and Snowdonia; however the number of rust recorders is low and the rarity may be of recorders who also climb mountains rather than the rust. I hoped to answer the question by targeting Oxyria in Snowdonia and to date I have not found any further records, suggesting it is genuinely uncommon/rare here. Rust recording is an exciting and rewarding passtime with the possibility of finding new VC records both for the individual rust species and for rusts occurring on new hosts. It additionally fills the gap in the spring and summer outside the main fungal season and can be thoroughly recommended!
4(
I K GH J > % && )# ' O O ON %)# ' ) C
4N O =L ?OFN 1 MN @ON IAK 2 ;FO
J K &$)(() ) O O M N #( #()( > C N F BN - JN A ON IA>3 2 ;FO
J 4 % && $")(&( "' O O 66 O / N ")(&( "' '! ) 5 :L
5 6 ML OBON = L 8N @ON IAK 2 ;FO
2+
I K GH J 5 % && !'& O O 66 FO M M N !'& "' ) 7 June 2007, = L 8N @ON IAK 2 ;FO
J 7 % && (") O O 66N L O N ") !" :L
5N A O G O O D M HN A O 2 ;FO
References
Further Reading
Aron, C. (2005). Fungi of Northwest Wales. Self-published. Evans, S. (2007). The Red Data List of Threatened British Fungi. Ing, B. (1978). Puccinia nemoralis – a new British rust. Trans. Brit. Mycol. Soc. 71: 325–329. Quilliam, R.S. & Shattock, R.C. (2003). Haustoria of microcyclic rust fungi Uromyces ficariae and Puccinia tumida and other gall-forming species, U. dactylidis (macrocyclic), and P. smyrnii (demicyclic). Plant Pathology, 52: 104-113. Shattock, R. (2004). Microcyclic Rusts, M-Haustoria and…..Mycophyllas? Field Mycology, 5(4): 132-136.
Ellis, M.B, & Ellis, J.P. (1997). Microfungi on Land Plants - An Identification Handbook. Richmond Publishing. Henderson, D.M. (2000). A Checklist of the Rust Fungi of the British Isles. British Mycological Society. Henderson, D.M. (2004). The Rust Fungi of the British Isles - A Guide to Identification by their Host Plants. British Mycological Society. Termorshuizen, A.J. & Swertz, C.A. (2011). Roesten: Roesten van Nederland (Dutch Rust Fungi). Wilson, M. & Henderson, D.M. (1966). British Rust Fungi. Cambridge University Press.
2,