Claviceps purpurea (Fr.) Tul.

Synonyms

Sclerotium clavus DC.
Spermoedia clavus Fr.
Sphaeria purpurea Fr.
Sphacelia segetum Lév.
Kentrosporium microsceohalum Wallr.
Kentrosporium mitratum Wall.
Sphaeria ascus Trog
Claviceps microcephala (Wallr.) Tul.
Cordyceps setulosa Quel.
Claviceps sesleriae (Quel.) Sacc.
Spermoedia microcephala (Wallr.) Seaver

Description

Sclerotia formed in the fertile florets of spikelets, replacing the ovaries and protruding past the spikelet elements on most hosts, cylindrical-fusoid, straight or curved, 2–50 x 3-4 mm, purplish black, with rounded or tapered apex, surface often wrinkled or with longitudional ridges.

Conidia of 1 type

  • macroconidia formed on narrow, flask-shaped terminal conidiogenous cells on the sphacelium and later immersed in honeydew, elliptical, 4–14 x 2–7 µm, hyaline, aseptate.

Ascostromata up to 60 stromata per sclerotium, each consisting of a globose capitulum, up to 2 mm in diameter, rose red-violet or cream purple, collar around the base of the capitulum,  borne by a slender stipe, 5-25 mm long, purple violet-lilac, glabrous.

Perithecia up to 200 per capitulum, ovoid-pyriform, 100–170 x 150–300 µm.

Asci clavate, 80-140 µm x 2-5 µm, hemispherical cap perforated by a fine pore.

Ascospores 8 per ascus, filiform, 50–140 µm x 0.6-1 µm, hyaline, septate.

Hosts
   
Host family: Poaceae
   
Host species: Achnatherum caudatum
Agrostis sp.
Ammophila arenaria
Arrhenatherum avenaceum
Austrodanthonia procera
Austrofestuca hookeriana
Austrofestuca littoralis
Austrostipa gibbosa
Austrostipa rudis

Avena sativa
Bromus hordeaceous
Bromus inermis
Dactylis glomerata
Deayeuxia quadriseta
Diplachne parviflora

Elymus racemosus
Elymus scaber
Festuca arundinacea
Festuca ovina
Festuca pratensis
Holcus lanatus
Hordeum leporinum
Hordeum vulgare

Lolium multiflorum
Lolium perenne
Lolium rigidum
Microlaena stipoides
Microlaena tasmanica
Phalaris aquatica
Phalaris canariensis
Phalaris minor
Phragmites australis
Piptatherum mileaceum
Poa annua
Poa clivicola
Poa fawcettiae
Poa labilliardieri
Poa poiformis
Poa pratensis
Pucciniella stricta
Secale cereale
Stipa sp.
Triticum aestivum
Vulpia bromoides

Distribution

ACT, NSW, QLD, SA, TAS, VIC, WA

Comments

In Australia this fungus is confined to temperate grasses. On the Australian specimens of C. purpurea, the morphology of the sclerotia vary considerably from host to host, ranging from straight to curved, and from 2–3 x 1 mm on specimens of Phalaris aquatica to 30–35 x 3–4 mm on specimens of Secale cereale. Evidence suggests that populations of C. purpurea are not host–specialised, but habitat–specialised, implying that suggested taxa below species level are not valid. The species purpurea produces a range of alkaloids, including agroclavine, ergonine, β–ergoptine, α–ergosine, ergostinine, ergotamine, and lysergene which have caused mycotoxoses in mammals, including humans, throughout recorded history. For example, a malady called “St Anthony’s Fire” occurred during the Middle Ages in Europe, causing hallucinations and gangrene in peasants who ingested rye bread contaminated with sclerotia of C. purpurea.

Highslide JS
Claviceps purpurea on Hordeum vulgare - BRIP 49127.
Scale bar = 1 cm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362. Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362. Scale bar = 500 µm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Microlaena stipoides - BRIP 8362.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Triticum aestivum - VPRI 10143.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Unknown host.
Scale bar = 1 cm.
Highslide JS
Claviceps purpurea on Unknown host.
Scale bar = 1 cm.
Highslide JS
Claviceps purpurea on Triticum aestivum.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Triticum aestivum.
Scale bar = 2 mm.
Highslide JS
Claviceps purpurea on Phalaris tuberosa.
Scale bar = 1 mm.
Highslide JS
Claviceps purpurea on Lolium perenne - DAR 57774.
Scale bar = 20 µm.
Highslide JS
Claviceps purpurea on Lolium perenne - DAR 57774.
Scale bar = 20 µm.