Claviceps nigricans Tul.

Description

Sclerotia formed in the fertile florets of spikelets and replacing the ovaries, semi-cylindrical, obtuse, often strongly curved, up to 12 mm long, black.

Conidia of one type

  • macroconidia formed on narrow, flask-shaped terminal conidiogenous cells on the sphacelium and later immersed in honeydew, oblong, 8-12 x 3-4 µm, hyaline, aseptate.

Ascostromata arising from sclerotia,each consisting of a globose capitulum 1.3-2 mm in diameter, dark violet-blackish violet, borne by a slender stipe up to 8 mm ling, dark violet.

Perithecia flask shaped.

Asci very long.

Ascospores filiform, 89-90 x 1 µm, hyaline.

Hosts
   
Host family: Poaceae
   
Host species: Eleocharis acuta

Distribution

NSW, SA

Comments

This rare fungus is the only Claviceps species recorded on a member of the Family Cyperaceae in Australia; it has been collected from just a few localities in N.S.W. and S.A. Specimens in Australian herbaria contain only the sclerotial and conidial states. The scant details of the sexual state are sourced from Tulasne’s original description of C. nigricans.

Highslide JS
Claviceps nigricans on Eleocharis acuta - BRIP 8181.
Scale bar = 1 cm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - DAR 59071. Scale bar = 5 mm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - DAR 59071. Scale bar = 5 mm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - DAR 59071.
Scale bar = 5 mm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - DAR 59071. Scale bar = 5 mm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - BRIP 8210.
Scale bar = 10 µm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - BRIP 8210.
Scale bar = 10 µm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - BRIP 8210.
Scale bar = 10 µm.
Highslide JS
Claviceps nigricans on Eleocharis acuta - BRIP 8210.
Scale bar = 10 µm.