Spiropes guareicola (F. Stevens) Cif., Sydowia 9(1-6): 302, 1955

Bermudez-Cova, Miguel A., Hofmann, Tina A., Yorou, Nourou S. & Piepenbring, Meike, 2024, Systematic revision of species of Atractilina and Spiropes hyperparasitic on Meliolales (Ascomycota) in the tropics, MycoKeys 103, pp. 167-213 : 167

Spiropes guareicola (F. Stevens) Cif., Sydowia 9(1-6): 302, 1955

Fig. 12

Helminthosporium guareicola ≡ Helminthosporium guareicola F. Stevens [as ' Helmisporium guareicolum '], Bot. Gaz. 65(3): 241, 1918.

Pleurophragmium guareicola ≡ Pleurophragmium guareicola (F. Stevens) S. Hughes, Can. J. Bot. 36: 797, 1958.

Cladosporium elegans = Cladosporium elegans var. singaporense Sacc., Bull. Orto Bot. Regia Univ. Napoli 6: 60, 1921.

Helminthosporium flagellatum = Helminthosporium flagellatum H.S. Yates [as ' Helmisporium '], Philipp. J. Sci. (Bot.) 13: 383, 1918.

Helminthosporium spirotrichum = Helminthosporium spirotrichum Sacc. [as ' Helmisporium '], Boll. Orto bot. 6: 61, 1921.

Description.

Colonies effuse, dark brown to black, hairy. Hyphae superficial, branched, septate, 2-4 µm wide, pale olivaceous-brown, smooth. Conidiophores arising singly or in groups, as lateral branches on the hyphae, erect, sterile lower part straight or flexuous, upper fertile part in zigzag shape, septate, up to 400 µm long, 6-9 µm thick, brown to dark brown, paler towards the apex, more or less smooth, with numerous well-defined, dark conidial scars. Conidia solitary, broadly fusiform, truncate at the base, with 3 to 5 pseudosepta, (25-)35-52(-60) × (7-)8-10(-13) µm, 3.5-5 µm wide at the base, pale to dark brown or olivaceous-brown, smooth as seen by SEM.

Specimen examined.

On leaves of Cyrtophyllum fragrans ( Gentianaceae ), Singapore, 1921, Baker (IMI 49160, type of Helminthosporium spirotrichum ); on Meliola sp. on leaves of Daniellia thurifera ( Fabaceae ), Sierra Leone, 1936, F.C. Deightonii M1267 (IMI 10010).

Illustrations.

This species was illustrated by Ellis (1968).

Known hosts and distribution.

On colonies of Asteridiella spp., Irenopsis spp. and Meliola spp. on living leaves of various plants in Bougainville Islands, Ghana, India, Indonesia, Malaysia, Philippines, Puerto Rico, Sabah, Sierra Leone, Solomon Islands and Uganda ( Ellis 1968).

Notes.

Spiropes guareicola is the type species of the genus Spiropes and it differs from other species of the genus by the presence of zigzag-shaped conidiophores in the fertile upper parts ( Ellis 1968). S. guareicola presents smooth conidia, a feature that is only evident by SEM.

Figures

Figure 12. Spiropes guareicola (IMI 10010) a conidiophore with scars and a young conidium shown in optical section b base of a conidiophore growing on a hypha of Meliola sp. shown in optical section c conidia shown in optical section (two drawings on the left-hand side) and as seen by SEM (two drawings on the right-hand side) d, e as seen by SEM d zigzag-shaped conidiophore with scars e conidium. Scale bars: 5 μm (a - c); 8 μm (d); 10 μm (e).